View source for Running

{{Short description|Method of terrestrial locomotion allowing rapid movement on foot}}
{{distinguish|Gait}}
{{other uses|Run (disambiguation)|Runner (disambiguation)|Runners (disambiguation)|Running (disambiguation)}}
{{pp|small=yes}}
{{Use dmy dates|date=August 2023}}
[[File:Runners JFK Memorial.jpg|thumb|[[Dallas Marathon]] runners passing by the [[John Fitzgerald Kennedy Memorial]] in 2024]]
[[File:Ludovic and Lauren (8425515069).jpg|thumb|[[Marathon]] runners at [[Carlsbad Marathon]], US, 2013]]
[[File:Running form.ogv|thumb|Video of human running action]]

'''Running''' is a method of [[terrestrial locomotion]] by which humans and other animals move quickly on foot. Running is a [[gait]] with an aerial phase in which all feet are above the ground (though there are exceptions).<ref>{{cite journal|title=Gait selection in the ostrich: mechanical and metabolic characteristics of walking and running with and without an aerial phase|date=22 May 2004|journal=Proceedings of the Royal Society of London B: Biological Sciences|volume=271|issue=1543|pages=1091–1099|doi=10.1098/rspb.2004.2702|pmid=15293864|pmc=1691699|last1=Rubenson|first1=Jonas|last2=Heliams|first2=Denham B.|last3=Lloyd|first3=David G.|last4=Fournier|first4=Paul A.}}</ref> This is in contrast to [[walking]], a slower form of movement where at least one foot is always in contact with the ground, the legs are kept mostly straight, and the [[center of gravity]] vaults over the stance leg or legs in an [[inverted pendulum]] fashion.<ref name="Bie">Biewener, A. A. 2003. Animal Locomotion. Oxford University Press, US. {{ISBN|978-0-19-850022-3}}, [https://books.google.com/books?id=yMaN9pk8QJAC&q=biomechanics+biewener books.google.com]</ref> A feature of a running body from the viewpoint of [[Spring mass system|spring-mass mechanics]] is that changes in [[Kinetic energy|kinetic]] and [[potential energy]] within a stride co-occur, with energy storage accomplished by springy tendons and passive muscle elasticity.<ref>{{Cite journal | last1 = Cavagna | first1 = G. A. | last2 = Saibene | first2 = F. P. | last3 = Margaria | first3 = R. | title = Mechanical Work in Running | journal = Journal of Applied Physiology | volume = 19 | issue = 2 | pages = 249–256 | year = 1964 | pmid = 14155290| doi=10.1152/jappl.1964.19.2.249}}</ref> The term "running" can refer to a variety of speeds ranging from [[jogging]] to [[Sprint (running)|sprinting]].

Running in humans is associated with improved health and [[life expectancy]].<ref>{{cite journal |last1=Pedisic |first1=Zeljko |last2=Shrestha |first2=Nipun |last3=Kovalchik |first3=Stephanie |last4=Stamatakis |first4=Emmanuel |last5=Liangruenrom |first5=Nucharapon |last6=Grgic |first6=Jozo |last7=Titze |first7=Sylvia |last8=Biddle |first8=Stuart JH |last9=Bauman |first9=Adrian E |last10=Oja |first10=Pekka |title=Is running associated with a lower risk of all-cause, cardiovascular and cancer mortality, and is the more the better? A systematic review and meta-analysis |journal=British Journal of Sports Medicine |date=4 November 2019 |volume=54 |issue=15 |pages=bjsports–2018–100493 |doi=10.1136/bjsports-2018-100493|pmid=31685526 |s2cid=207895264 |url=https://vuir.vu.edu.au/40291/1/Pedisic_etal%282020%29-Is_running_associated_with_alower_risk.pdf |archive-url=https://web.archive.org/web/20211010190733/https://vuir.vu.edu.au/40291/1/Pedisic_etal%282020%29-Is_running_associated_with_alower_risk.pdf |archive-date=10 October 2021 |url-status=live }}</ref>

It is hypothesized that the ancestors of humankind developed the ability to run for long distances about 2.6&nbsp;million years ago, probably to [[Hunting|hunt animals]].<ref>{{cite web|url=http://discovermagazine.com/2006/may/tramps-like-us|title=Born To Run – Humans can outrun nearly every other animal on the planet over long distances.|year=2006|page=3|work=Discover Magazine}}</ref><ref>{{cite book |last=Heinrich |first=Bernd |date=7 May 2009 |title=Why we run: A natural history |publisher=Harper Collins |isbn=978-0060958701}}</ref> Competitive running grew out of religious festivals in various areas. Records of competitive [[racing]] date back to the [[Tailteann Games (ancient)|Tailteann Games]] in [[Ireland]] between 1171 BCE and 632 BCE,<ref>{{Cite web|url=https://search.credoreference.com/content/entry/galefit/running/0|title = Running &#124; the Gale Encyclopedia of Fitness - Credo Reference}}</ref><ref name=":0">{{Cite book|title=What Is Sport: A Controversial Essay About Why Humans Play Sports|last=Alpha|first=Rob|publisher=BookBaby|year=2015|isbn=9781483555232}}</ref><ref>{{Cite web|url=https://healthandfitnesshistory.com/explore-history/history-of-running/|title=History of Running|date=23 November 2018|website=Health and Fitness History|access-date=23 November 2018}}</ref> while the first recorded [[Ancient Olympic Games|Olympic Games]] took place in 776 BCE. Running has been described as the world's most accessible sport.<ref>Soviet Sport: The Success Story. p. 49, V. Gerlitsyn, 1987</ref>
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==History==
{{See also|History of physical training and fitness}}
[[File:Long Distance Runners, Ancient Greece, Amphora.png|thumb|An early 20th Century drawing depicting long-distance runners. It is copied from a [[Panathenaic amphora]] from Ancient Greece, circa 333 BCE<ref>{{cite book |last1=Gardiner |first1=E. Norman |title=Greek Athletic Sports and Festivals |date=1910 |publisher=MacMillan |page=280, Fig. 51}}</ref>]]
[[File:Atalanta Lepautre Louvre MR1804.jpg|thumb|A statue of [[Atalanta]] the mythical runner who could not be beaten in a race. Produced circa 1703-1705, this statue is a copy of a Roman statue which itself was copied from a Hellenistic original.]]

It is thought that human running evolved at least four and a half million years ago out of the ability of the ape-like [[Australopithecus]], an early ancestor of humans, to [[bipedalism|walk upright on two legs]].<ref>{{cite web |url=http://www.runtheplanet.com/resources/historical/runevolve.asp |title=The Evolution of Human Running: Training & Racing |publisher=runtheplanet.com |access-date=26 June 2010 }}</ref>

Early humans most likely developed into endurance runners from the practice of [[persistence hunting]] of animals, the activity of following and chasing until a prey is too exhausted to flee, succumbing to "chase [[myopathy]]" (Sears 2001), and that human features such as the [[nuchal ligament]], abundant [[sweat glands]], the [[Achilles tendon]]s, big [[knee joint]]s and muscular [[glutei maximi]], were changes caused by this type of activity (Bramble & Lieberman 2004, et al.).<ref>{{cite journal | author = Ingfei Chen |url=http://discovermagazine.com/2006/may/tramps-like-us |title=Born To Run |journal=Discover |date=May 2006 |access-date=26 June 2010 }}</ref><ref name="Liebenberg ">{{cite journal |jstor=10.1086/508695 |author=Louis Liebenberg |title=Persistence Hunting by Modern Hunter-Gatherers |journal=Current Anthropology |date=December 2006 |publisher=Current Anthropology & The University of Chicago Press |volume=47 |issue=6 |pages=1017–1026|doi=10.1086/508695 |s2cid=224793846 }}</ref><ref name="Sears ">{{cite book |url=https://books.google.com/books?id=vxxOw3FvOgwC&q=History+of+Running|author=Edward Seldon Sears |title=Running Through the Ages |publisher=McFarland, 2001| access-date=9 April 2012|isbn=9780786450770 |date=22 December 2008 }}</ref> The theory as first proposed used comparative physiological evidence and the natural habits of animals when running, indicating the likelihood of this activity as a successful hunting method. Further evidence from observation of modern-day hunting practices also indicated this likelihood (Carrier et al. 1984).<ref name="Sears "/><ref name=" David R. Carrier, A. K. Kapoor, Tasuku Kimura, Martin K. Nickels, Satwanti, Eugenie C. Scott, Joseph K. So and Erik Trinkaus">{{cite journal|author=David R. Carrier, A. K. Kapoor, Tasuku Kimura, Martin K. Nickels, Satwanti, Eugenie C. Scott, Joseph K. So and Erik Trinkaus |title=The Energetic Paradox of Human Running and Hominid Evolution and Comments and Reply |journal=Current Anthropology |volume=25 |issue = 4|pages=483–495 |publisher=The University of Chicago Press|jstor=2742907 |year=1984 |doi=10.1086/203165 |s2cid=15432016 }}</ref> According to Sears (p.&nbsp;12) scientific investigation (Walker & Leakey 1993) of the [[Nariokotome skeleton]] provided further evidence for the Carrier theory.<ref name="Walker, & Leakey  ">{{cite book |url=https://books.google.com/books?id=3jNburL7OcgC&q=running |author1=Alan Walker |author2=Richard Leakey |title=The Nariokotome Homo Erectus Skeleton | page= 414|publisher=Springer, 1993| access-date=9 April 2012|isbn=9783540563013 |date=16 July 1996 }}</ref>

Competitive running grew out of religious festivals in various areas such as Greece, Egypt, Asia, and the [[East African Rift]] in Africa. The [[Tailteann Games (ancient)|Tailteann Games]], an Irish sporting festival in honor of the goddess [[Tailtiu]], dates back to 1829 BCE and is one of the earliest records of competitive running.<ref>{{Cite book|last=Matthews|first=Peter|url=https://books.google.com/books?id=dQFHe9RwE0wC&pg=PA2|title=Historical Dictionary of Track and Field|date=2012|publisher=Scarecrow Press|isbn=978-0-8108-6781-9|language=en}}</ref> The [[Ancient Olympic Games#Origin mythology|origins of the Olympics]] and [[marathon|Marathon running]] are shrouded by myth and legend, though the first recorded games took place in 776 BCE.<ref>{{cite book |url=https://books.google.com/books?id=cgkzWTugSj0C&pg=PA201|title=The Ancient Olympics|isbn=978-0-19-280604-8 |year=2006 |last1=Spivey |first1=Nigel |publisher=Oxford University Press }}</ref> [[Running in Ancient Greece]] can be traced back to these games of 776 BCE.

{{Blockquote|...I suspect that the sun, moon, earth, stars, and heaven, which are still the gods of many barbarians, were the only gods known to the aboriginal Hellenes. Seeing that they were always moving and running, from their running nature they were called gods or runners (Thus, Theontas)...|[[Socrates]] in [[Plato]] – ''[[Cratylus]]''<ref>Plato (translated by B.Jowett) - [http://classics.mit.edu/Plato/cratylus.html Cratylus] MIT [Retrieved 2015-3-28]</ref>}}

The culture of running was not limited to men in Ancient Greece and is demonstrated by the mythical [[Atalanta]]. Her [[suitors]] were required to beat her in a race or forfeit their lives. As she was unbeatable, all failed except for [[Hippomenes]] who was aided by the goddess [[Venus]]. He distracted Atalanta during the race by throwing golden apples, given to him by Venus, which she stooped to pick up. The details of the event illuminate the running technique which was considered effective in the contemporary culture.<ref>{{cite book |last1=Sears |first1=Edward S. |title=Running Through The Ages |date=2001 |publisher=McFarland and Company |location=Jefferson |isbn=978-0-7864-4094-8 |page=17}}</ref>  In ''[[Metamorphoses]]'' the Roman writer [[Ovid]] gives Venus's spoken account of the start of the race: {{Blockquote|The trumpet sounded the start: The pair, each crouching low, shot forward, skimming the sand with flying feet, so lightly they could run on waves and never wet their sandals, they could run on fields of grain and never bend them. He heard them cheering: Go Hippomenes, lean to the work, use all your strength: go, go, you are sure to win!<ref>{{cite book |last1=Sears |first1=Edward S. |title=Running Through The Ages |date=2001 |publisher=McFarland and Company |location=Jefferson |isbn=978-0-7864-4094-8 |page=17}}</ref> }} 

Such involvement of women in running found concrete representation in the [[Heraean Games]]. These were a series of events which took place immediately before the [[Ancient Olympic Games]] and which only women could compete in.<ref>Gardiner, E. Norman, 'The Rise of the Athletic Festival' in ''Greek Athletic Sport and Festivals'', London:MacMillan, 1910, pp. 47–48</ref> Writing in the early 20th Century, the historian E. Norman Gardinier states: {{Blockquote| At the festival there were races for maidens of various ages. Their course was 500 feet, or one-sixth less than the men's stadium. The maidens ran with their hair down their backs, a short tunic reaching just below the knee, and their right shoulder bare to the breast. The victors received crowns of olive and a share of the heifer sacrificed to Hera. They had, too, the right of setting up their statues in the Heraeum.<ref>Gardiner, E. Norman, 'The Rise of the Athletic Festival' in ''Greek Athletic Sport and Festivals'', London:MacMillan, 1910, pp. 47–48</ref>}}

==Description==
[[File:Muybridge runner.jpg|thumb|[[Eadweard Muybridge]] photo sequence]]

Running gait can be divided into two phases regarding the lower [[Limb (anatomy)|extremity]]: stance and swing.<ref name="Anderson 1996 76–89">{{cite journal|last=Anderson|first=T|title=Biomechanics and Running Economy|journal=Sports Medicine|year=1996|volume=22|issue=2|pages=76–89|doi=10.2165/00007256-199622020-00003|pmid=8857704|s2cid=22159220}}</ref><ref name="Nicola 2012 187–201">{{cite journal |last1=Nicola |first1=T. L. |last2=Jewison |first2=D. J. |title=The Anatomy and Biomechanics of Running|journal=Clinical Journal of Sport Medicine|year=2012|volume=31|issue=2 |pages=187–201|doi=10.1016/j.csm.2011.10.001|pmid=22341011 }}</ref><ref name="Novacheck 1998 77–95">{{cite journal|last=Novacheck|first=T.F.|title=The biomechanics of running|journal=Gait & Posture|year=1998|volume=7|issue=1|pages=77–95|doi=10.1016/s0966-6362(97)00038-6|pmid=10200378|s2cid=2057865 }}</ref><ref name="Schache 1999 30–47">{{cite journal|last=Schache|first=A.G.|title=The coordinated movement of the lumbo-pelvic-hip complex during running: a literature review|journal=Gait & Posture|year=1999|volume=10|issue=1|pages=30–47|doi=10.1016/s0966-6362(99)00025-9|pmid=10469939}}</ref> These can be further divided into absorption, propulsion, initial swing, and terminal swing.  Due to the continuous nature of running gait, no certain point is assumed to be the beginning.  However, for simplicity, it will be assumed that absorption and footstrike mark the beginning of the running cycle in a body already in motion.

===Footstrike===
Footstrike occurs when a plantar portion of the foot makes initial contact with the ground.  Common footstrike types include forefoot, midfoot, and heel strike types.<ref name="Daoud 2012 1325–34">{{cite journal|last=Daoud|first=A.I.|title=Foot Strike and Injury Rates in Endurance Runners: a retrospective study|journal= Medicine and Science in Sports and Exercise|year=2012|volume=44|issue=7|pages=1325–1334|doi=10.1249/mss.0b013e3182465115|pmid=22217561|s2cid=14642908|doi-access=free}}</ref><ref>{{cite journal|last=Larson|first=P|title=Foot strike patterns of recreational and sub-elite runners in a long-distance road race|journal=Journal of Sports Sciences|year=2011|volume=29|issue=15|pages=1665–1673|doi=10.1080/02640414.2011.610347|pmid=22092253|s2cid=12239202}}</ref><ref>{{cite journal|last=Smeathers|first=J.E.|title=Transient Vibrations Caused by Heel Strike|journal= Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine|year=1989|volume=203|issue=4|pages=181–186|doi=10.1243/PIME_PROC_1989_203_036_01|pmid=2701953|s2cid=36483935}}</ref> These are characterized by initial contact of the ball of the foot, ball and heel of the foot simultaneously and heel of the foot respectively.  During this time, the [[hip joint]] is undergoing extension from being in maximal flexion from the previous swing phase.  For proper force absorption, the knee joint should be flexed upon the footstrike, and the ankle should be slightly in front of the body.<ref name="Davis 1980 1590–95">{{cite journal|last=Davis|first=G.J.|title=Mechanisms of Selected Knee Injuries|journal=Journal of the American Physical Therapy Association|year=1980|volume=60|pages=1590–1595}}</ref> Footstrike begins the absorption phase as forces from initial contact are attenuated throughout the lower extremity. Absorption of forces continues as the body moves from footstrike to midstance due to vertical propulsion from the toe-off during a previous gait cycle.

===Midstance===
Midstance is when the lower extremity limb of focus is in knee flexion directly underneath the trunk, pelvis, and hips.  At this point, propulsion begins to occur as the hips undergo hip extension, the knee joint undergoes extension, and the ankle undergoes plantar flexion.  Propulsion continues until the leg is extended behind the body and toe-off occurs.  This involves a maximal hip extension, knee extension, and plantar flexion for the subject, resulting in the body being pushed forward from this motion, and the ankle/foot leaves the ground as the initial swing begins.

===Propulsion phase===
Research, especially in the footstrike debate, has primarily focused on identifying and preventing injuries during the absorption phases of running. The propulsion phase, which occurs from midstance to toe-off, is crucial for understanding how the body moves forward.<ref name="Nicola 2012 187–201" /><ref name="Novacheck 1998 77–95" /><ref name="Hammer 2010 2709–16">{{cite journal |last=Hammer |first=S.R. |year=2010 |title=Muscle contributions to propulsion and support during running |journal=Journal of Biomechanics |volume=43 |issue=14 |pages=2709–2716 |doi=10.1016/j.jbiomech.2010.06.025 |pmc=2973845 |pmid=20691972}}</ref> 

In a full stride length model, elements of both the terminal swing and footstrike contribute to propulsion.<ref name="Schache 1999 30–47" /><ref name="Ardigo 2008 17–22">{{cite journal |last=Ardigo |first=L.P. |year=2008 |title=Metabolic and mechanical aspects of foot landing type, forefoot, and rearfoot strike, in human running |journal=Acta Physiologica Scandinavica |volume=155 |issue=1 |pages=17–22 |doi=10.1111/j.1748-1716.1995.tb09943.x |pmid=8553873}}</ref> 
The setup for propulsion begins at the end of the terminal swing when the hip joint flexes, allowing the hip extensors to generate force as they accelerate through the maximal range of motion.

As the hip extensors transition from inhibitory to primary muscle movers, the lower extremity moves back towards the ground, aided by the [[stretch reflex]] and gravity.<ref name="Schache 1999 30–47" /> The footstrike and absorption phases follow, leading to two possible outcomes.

With a heel strike, this phase may be just a continuation of momentum from the stretch reflex, gravity, and light hip extension, offering little force absorption through the ankle joint.<ref name="Hammer 2010 2709–16" /><ref name="Bergmann 2000 817–827">{{cite journal |last=Bergmann |first=G. |year=2000 |title=Influence of shoes and heel strike on the loading of the hip joint |journal=Journal of Biomechanics |volume=28 |issue=7 |pages=817–827 |doi=10.1016/0021-9290(94)00129-r |pmid=7657680}}</ref><ref name="Lieberman 2010 531–535">{{cite journal |last=Lieberman |first=D. |year=2010 |title=Foot strike patterns and collision forces in habitually barefoot versus shod runners |journal=Nature |volume=463 |issue=7280 |pages=531–535 |bibcode=2010Natur.463..531L |doi=10.1038/nature08723 |pmid=20111000 |s2cid=216420}}</ref> On the other hand, a mid/forefoot strike helps in shock absorption, supporting plantar flexion from midstance to toe-off.<ref name="Lieberman 2010 531–535" /><ref name="Williams 2000 210–218">{{cite journal |last=Williams |first=D.S. |year=2000 |title=Lower Extremity Mechanics in Runners with a Converted Forefoot Strike Pattern |journal=Journal of Applied Biomechanics |volume=16 |issue=2 |pages=210–218 |doi=10.1123/jab.16.2.210}}</ref>

The actual propulsion begins when the lower extremity enters midstance.<ref name="Hammer 2010 2709–16" /> The hip extensors continue contracting, assisted by gravity and the stretch reflex from maximal hip flexion during the terminal swing. Hip extension pulls the ground underneath the body, propelling the runner forward.

During midstance, the knee should be slightly flexed due to elastic loading from the absorption and footstrike phases, preserving forward momentum.<ref name="Kubo 2000 181–187">{{cite journal |last=Kubo |first=K. |year=2000 |title=Elastic properties of muscle-tendon complex in long-distance runners |journal=European Journal of Applied Physiology |volume=81 |issue=3 |pages=181–187 |doi=10.1007/s004210050028 |pmid=10638375 |s2cid=10044650}}</ref><ref name="Magness">{{cite web |last=Magness |first=S. |date=4 August 2010 |title=How to Run: Running with proper biomechanics |url=http://www.scienceofrunning.com/2010/08/how-to-run-running-with-proper.html |access-date=3 October 2012}}</ref><ref name="Thys 1975 281–286">{{cite journal |last=Thys |first=H. |year=1975 |title=The role played by elasticity in an exercise involving movements of small amplitude |journal=European Journal of Physiology |volume=354 |issue=3 |pages=281–286 |doi=10.1007/bf00584651 |pmid=1167681 |s2cid=21309186}}</ref> The ankle joint is in [[dorsiflexion]] at this point, either elastically loaded from a mid/forefoot strike or preparing for stand-alone concentric plantar flexion.

The final propulsive movements during toe-off involve all three joints: ankle, knee, and hip.<ref name="Hammer 2010 2709–16" /><ref name="Bergmann 2000 817–827" /><ref name="Lieberman 2010 531–535" /><ref name="Williams 2000 210–218" /> The plantar flexors push off from the ground, returning from dorsiflexion in midstance. This can occur either by releasing the elastic load from an earlier mid/forefoot strike or through concentric contraction from a heel strike.

With a forefoot strike, the ankle and knee joints release their stored elastic energy from the footstrike/absorption phase.<ref name="Kubo 2000 181–187" /><ref name="Magness" /><ref name="Thys 1975 281–286" /> The quadriceps group/knee extensors fully extend the knee, pushing the body off the ground. Simultaneously, the knee flexors and stretch reflex pull the knee back into flexion, initiating the initial swing phase. The hip extensors extend to the maximum, contributing to forces pulling and pushing off the ground, as well as initiating knee flexion and the initial swing phase.

===Swing phase===
Initial swing is the response of both stretch reflexes and concentric movements to the propulsion movements of the body.  Hip flexion and knee flexion occur, beginning the return of the limb to the starting position and setting up for another foot strike.  The initial swing ends at midswing when the limb is again directly underneath the trunk, pelvis, and hip with the knee joint flexed and hip flexion continuing.  Terminal swing then begins as hip flexion continues to the point of activation of the stretch reflex of the hip extensors.  The knee begins to extend slightly as it swings to the anterior portion of the body.  The foot then makes contact with the ground with a foot strike, completing the running cycle of one side of the lower extremity.
Each limb of the lower extremity works opposite to the other.  When one side is in toe-off/propulsion, the other hand is in the swing/recovery phase preparing for footstrike.<ref name="Anderson 1996 76–89"/><ref name="Nicola 2012 187–201"/><ref name="Novacheck 1998 77–95"/><ref name="Schache 1999 30–47"/> Following toe-off and the beginning of the initial swing of one side, there is a flight phase where neither extremity is in contact with the ground due to the opposite side finishing terminal swing.  As the footstrike of the one hand occurs, the initial swing continues.  The opposing limbs meet with one in midstance and midswing, beginning the propulsion and terminal swing phases.

===Upper extremity function===
[[file:Police running in North Point lockdown area 20210128.gif|thumb|upright=1.1|Video of man running]]
The upper extremity function serves mainly in providing balance in conjunction with the opposing side of the lower extremity.<ref name="Nicola 2012 187–201"/> The movement of each leg is paired with the opposite arm, which serves to counterbalance the body, particularly during the stance phase.<ref name="Hammer 2010 2709–16"/> The arms move most effectively (as seen in elite athletes) with the elbow joint at approximately 90 degrees or less, the hands swinging from the hips up to mid-chest level with the opposite leg, the Humerus moving from being parallel with the trunk to approximately 45 degrees shoulder extension (never passing the trunk in flexion) and with as little movement in the transverse plane as possible.<ref name="Cavanagh 1990">{{cite book|last=Cavanagh|first=P.R.|title=Biomechanics of Distance Running|year=1990|publisher=Human Kinetics Books|location=Champaign, I.L}}</ref> The trunk also rotates in conjunction with arm swing. It mainly serves as a balance point from which the limbs are anchored.  Thus trunk motion should remain mostly stable with little motion except for slight rotation, as excessive movement would contribute to transverse motion and wasted energy.

===Footstrike debate===
Recent research into various forms of running has focused on the differences in the potential [[injury]] risks and shock absorption capabilities between heel and mid/forefoot footstrikes.  It has been shown that heel striking is generally associated with higher rates of injury and impact due to inefficient shock absorption and inefficient biomechanical compensations for these forces.<ref name="Daoud 2012 1325–34"/> This is due to pressures from a heel strike traveling through bones for shock absorption rather than being absorbed by muscles.  Since bones cannot disperse forces easily, the forces are transmitted to other parts of the body, including ligaments, joints, and bones in the rest of the lower extremities up to the lower back.<ref>{{cite journal|last=Verdini|first=F.|title=Identification and characterization of heel strike transient|journal=Gait & Posture|year=2005|volume=24|issue=1|pages=77–84|doi=10.1016/j.gaitpost.2005.07.008|pmid=16263287|hdl=11566/25362 }}</ref> This causes the body to use abnormal compensatory motions in an attempt to avoid serious bone injuries.<ref>{{cite journal|last=Walter|first=N.E.|title=Stress fractures in young athletes|journal=The American Journal of Sports Medicine|year=1977|volume=5|issue=4|pages=165–170|doi=10.1177/036354657700500405|pmid=883588|s2cid=39643507}}</ref> These compensations include internal rotation of the tibia, knee, and hip joints.  Excessive compensation over time has been linked to a higher risk of injuries in those joints and the muscles involved in those motions.<ref name="Bergmann 2000 817–827"/> Conversely, a mid/forefoot strike has been associated with greater efficiency and lower injury risk due to the [[Triceps surae muscle|triceps surae]] being used as a lever system to absorb forces with the muscles eccentrically rather than through the bone.<ref name="Daoud 2012 1325–34"/> Landing with a mid/forefoot strike has also been shown to properly attenuate shock and allow the triceps surae to aid in propulsion via reflexive plantarflexion after stretching to absorb ground contact forces.<ref name="Ardigo 2008 17–22"/><ref>{{cite journal|last=Perl|first=D.P|title=Effects of Footwear and Strike Type of Running Economy|journal= Medicine & Science in Sports & Exercise|year=2012|volume=44|issue=7|pages=1335–1343|doi=10.1249/mss.0b013e318247989e|pmid=22217565|s2cid=449934|doi-access=free}}</ref> Thus a mid/forefoot strike may aid in propulsion.
However, even among elite athletes, there are variations in self-selected footstrike types.<ref>{{cite journal|last=Hasegawa|first=H.|title=Foot Strike Patterns of Runners at the 15-km Point During Elite-Level Half Marathon|journal=Journal of Strength and Conditioning Research|year=2007|volume=21|issue=3|pages=888–893|doi=10.1519/00124278-200708000-00040|pmid=17685722}}</ref> This is especially true in longer distance events, where there is a prevalence of heel strikers.<ref>{{cite journal|last=Larson|first=P.|title=Foot strike patterns of recreational and sub-elite runners in a long-distance road race|journal=Journal of Sports Sciences|year=2011|volume=29|issue=15|pages=1665–1673|doi=10.1080/02640414.2011.610347|pmid=22092253|s2cid=12239202}}</ref> There does tend however to be a greater percentage of mid/forefoot striking runners in the elite fields, particularly in the faster racers and the winning individuals or groups.<ref name="Cavanagh 1990"/> While one could attribute the faster speeds of elite runners compared to recreational runners with similar footstrikes to physiological differences, the hip, and joints have been left out of the equation for proper propulsion.  This raises the question of how heel-striking elite distance runners can keep up such high paces with a supposedly inefficient and injurious foot strike technique.

===Stride length, hip and knee function===
Biomechanical factors associated with elite runners include increased hip function, use, and stride length over recreational runners.<ref name="Cavanagh 1990"/><ref name="Pink 1994 541–549">{{cite journal|last=Pink|first=M.|title=Lower Extremity Range of Motion in the Recreational Sport Runner|journal=American Journal of Sports Medicine|year=1994|volume=22|issue=4|pages=541–549|doi=10.1177/036354659402200418|pmid=7943522|s2cid=1744981}}</ref> An increase in running speeds causes increased ground reaction forces, and elite distance runners must compensate for this to maintain their pace over long distances.<ref name="Weyand 2010 1991–1999">{{cite journal|last=Weyand|first=P.G.|title=Faster top running speeds are achieved with greater ground forces not more rapid leg movements|journal=Journal of Applied Physiology|year=2010|volume=89|issue=5|pages=1991–1999|doi=10.1152/jappl.2000.89.5.1991|pmid=11053354|s2cid=2448066|doi-access=free}}</ref>
These forces are attenuated through increased stride length via increased hip flexion and extension through decreased ground contact time and more energy being used in propulsion.<ref name="Weyand 2010 1991–1999"/><ref>{{cite journal|last=Mercer|first=J.A.|title=Individual Effects of Stride Length and Frequency on Shock Attenuation during Running|journal= Medicine & Science in Sports & Exercise|year=2003|volume=35|issue=2|pages=307–313|doi=10.1249/01.mss.0000048837.81430.e7|pmid=12569221|s2cid=23896334 |doi-access=free}}</ref><ref>{{cite journal|last=Stergiou|first=N.|title=Subtalara and knee joint interaction during running at various stride lengths|journal=Journal of Sports Medicine and Physical Fitness|year=2003|volume=43|issue=3|pages=319–326|pmid=14625513 }}</ref> With increased propulsion in the horizontal plane, less impact occurs from the decreased force in the vertical plane.<ref>{{cite journal|last=Mercer|first=J.A.|title=Relationship between shock attenuation and stride length during running at different velocities|journal=European Journal of Applied Physiology|year=2002|volume=87|issue=4–5|pages=403–408|doi=10.1007/s00421-002-0646-9|pmid=12172880|s2cid=26016865}}</ref> Increased hip flexion allows for increased use of the hip extensors through midstance and toe-off, allowing for more force production.<ref name="Hammer 2010 2709–16"/>
The difference even between world-class and national-level 1500-m runners has been associated with more efficient hip joint function.<ref name="Leskinen 2009 1–9">{{cite journal|last=Leskinen|first=A.|title=Comparison of running kinematics between elite and national-standard 1500-m runners|journal=Sports Biomechanics|year=2009|volume=8|issue=1|pages=1–9|doi=10.1080/14763140802632382|pmid=19391490|s2cid=25422801}}</ref> The increase in velocity likely comes from the increased range of motion in hip flexion and extension, allowing for greater acceleration and speed.  The hip extensors and extension have been linked to more powerful knee extension during toe-off, contributing to propulsion.<ref name="Cavanagh 1990"/>
Stride length must be appropriately increased with some degree of knee flexion maintained through the terminal swing phases, as excessive knee extension during this phase along with footstrike has been associated with higher impact forces due to braking and an increased prevalence of heel striking.<ref>{{cite journal|last=Lafortune|first=M.A.|title=Dominant role of interface over knee angle for cushioning impact loading and regulating initial leg stiffness|journal=Journal of Biomechanics|year=2006|volume=29|issue=12|pages=1523–1529|doi=10.1016/s0021-9290(96)80003-0|pmid=8945650}}</ref> Elite runners tend to exhibit some degree of knee flexion at footstrike and midstance, which first serves to eccentrically absorb impact forces in the quadriceps muscle group.<ref name="Leskinen 2009 1–9"/><ref>{{cite journal|last=Skoff|first=B.|title=Kinematic analysis of Jolanda Ceplak's running technique|journal=New Studies in Athletics|year=2004|volume=19|issue=1|pages=23–31}}</ref><ref>{{cite journal|last=Skoff|first=B|title=Kinematic analysis of Jolanda Ceplak's running technique|journal=New Studies in Athletics|year=2004|volume=19|issue=1|pages=23–31}}</ref> Secondly it allows for the knee joint to contract concentrically and provides significant aid in propulsion during toe-off as the quadriceps group is capable of producing large amounts of force.<ref name="Hammer 2010 2709–16"/>
Recreational runners have been shown to increase stride length through increased knee extension rather than increased hip flexion, as exhibited by elite runners, which provides an intense braking motion with each step and decreases the rate and efficiency of knee extension during toe-off, slowing down speed.<ref name="Pink 1994 541–549"/> Knee extension, however, contributes to additional stride length and propulsion during toe-off and is seen more frequently in elite runners as well.<ref name="Cavanagh 1990"/>

==Good technique==
{{How-to|date=October 2022}}
{{multiple image |perrow = 1
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|width2 = 250 |image2 = Running Wild (5849602135).jpg |caption2 =
|footer= The runner's posture should be upright and slightly tilted forward.}}

===Upright posture and slight forward lean===
Leaning forward places a runner's [[center of mass]] over the front part of the foot, which avoids landing on the heel and facilitates the use of the spring mechanism of the foot. Additionally, it facilitates avoiding the braking effect that occurs when a runner lands their foot in front of the center of mass. Although maintaining an upright posture is crucial, runners should also keep their frame relaxed and engage their core to keep their posture stable. This helps prevent injury as long as the body is neither rigid nor tense. The most common running mistakes are tilting the chin up and scrunching shoulders.<ref name="Dr. Michael Yessis 2000">{{cite book |author= Michael Yessis |title= Explosive Running |publisher= McGraw-Hill Companies, Inc. |edition= 1st |year= 2000 |isbn= 978-0-8092-9899-0 |url-access= registration |url=https://archive.org/details/explosiverunning0000yess }}</ref>

===Stride rate and types===

During running, the [[speed]] at which the runner moves may be calculated by multiplying the [[cadence (gait)|cadence]] (steps per minute) by the stride length. {{anchor|Pace}}Running is often measured in terms of '''pace''',<ref>{{cite web|url=http://revelsports.com/pace_Chart.htm|title=Revel Sports Pace Chart|work=revelsports.com|date=25 November 2021}}</ref> expressed in [[Unit of measurement|units]] of minutes per mile or minutes per kilometer (the [[Multiplicative inverse|inverse]] of speed, in mph or km/h).
Some coaches advocate training at a combination of specific paces related to one's fitness to stimulate various physiological improvements.<ref>{{cite web |url=http://pfitzinger.com/marathontraining.shtml |title=Pete Pfitzinger – Training Information for Runners – Optimal Marathon Training |publisher=Pfitzinger.com |accessdate=21 August 2012 |archive-date=7 February 2016 |archive-url=https://web.archive.org/web/20160207220219/http://pfitzinger.com/marathontraining.shtml |url-status=dead }}</ref>

===Left and right balance===
{{See also| Unilateral training}}
It is common for a runner to have an asymmetric gait pattern which has a dominant side. The leg on this side applies slightly more power than the other leg and has a slightly longer stride length.<ref>{{cite book |last1=Houglum, Peggy A. & Bertoti, Dolores B. |title=Brunnstrom's Clinical Kinesiology |date=2012 |publisher=F. A. Davis Company |location=Philadelphia |isbn=978-0-8036-2352-1 |page=547 |edition=6th}}</ref> However, if the dominant leg is excessively stronger than the non-dominant leg, which is excessively weaker, then this can lead to problems with the person’s running technique, reduce efficiency, and increase the risk of injury. It can therefore be advantageous to even up the strength of the legs in order to achieve a more balanced gait overall.<ref>{{cite journal |last1=Holland |first1=Tom |title=Unilateral Strength |journal=Running Times |date=Sep 2007 |pages=14–16 |url=https://books.google.com/books?id=8sUDAAAAMBAJ&dq=running+unilateral+exercise+muscle+imbalance&pg=PA14 |access-date=26 July 2025}}</ref> 

This may be achieved in several ways. The gait can be altered so that the non-dominant leg is used as the dominant leg for a period of time i.e. by making its stride length slightly longer than that of the other leg and by applying the additional power needed to achieve this. The gait can then be periodically alternated so that both legs are used alternatively as the dominant leg. For example, during a run the left leg is used as the dominant leg with a slightly longer stride length than the right. Then, after a period of time, there is a change so that the right leg is used as the dominant leg with a slightly longer stride length than the left. And so forth in a pattern of alternation. This more even use of the legs overall means that any strength imbalances that have developed are reduced.<ref>{{cite book |last1=Beck |first1=Kevin |title=Run Strong |date=2005 |publisher=Human Kinetics |location=Champaign |isbn=0-7360-5362-X |chapter=Striving for symmetry, Developing proper alignment, Perfecting running form}}</ref> This can also be achieved by running around in a circle, first in one direction and then in the other. This is standardly practiced by runners who use oval running tracks. For example, when running anti-clockwise the inside left stride is shorter and the outside right stride is longer.<ref>{{cite journal |last1=Maćkała, Krzysztof & Michalski, Ryszard & Ćoh, Milan |title=Asymmetry of Step Length in Relationship to Leg Strength in 200 meters Sprint of different Performance Levels |journal=Journal of Human Kinetics |date=2010 |volume=25 |issue=2010 |page=106 |doi=10.2478/v10078-010-0037-y |doi-access=free }}</ref> In order to prevent a large muscle imbalance developing, runners also practice running clockwise so that, conversely, the right inside stride length is shorter and the left longer. This develops both the left and right sides more evenly.<ref>{{cite web |last1=Henricks |first1=Mark |title=Why you have one side stronger than the other and how to fix it |url=https://www.runnersworld.com/uk/health/a775316/why-you-have-one-side-stronger-than-the-other-and-how-to-fix-it/ |website=Runners World |date=December 2016 |access-date=26 July 2025}}</ref> Exercises which work the legs in a unilateral manner are also used. Using the legs one at a time, with the same range of movement for each, helps to ensure a more even strength ratio existing between them. For example, doing one legged squats on the left leg, before switching to do them on the right leg, ensures each leg performs the same amount of work and thereby evens up their strength levels.<ref>{{cite journal |last1=Holland |first1=Tom |title=Unilateral Strength |journal=Running Times |date=Sep 2007 |pages=14–16 |url=https://books.google.com/books?id=8sUDAAAAMBAJ&dq=running+unilateral+exercise+muscle+imbalance&pg=PA14 |access-date=26 July 2025}}</ref> Standardly, higher performance runners have more of an even balance between the relative strengths of their legs.<ref>{{cite journal |last1=Kong, Pui W. & de Heer, Hendrick |title=Anthropometric, Gait and Strength Characteristics of Kenyan Distance Runners |journal=Journal of Sports Science and Medicine |date=2008 |volume=7 |issue=7 |pages=499–504 |pmid=24149957 |pmc=3761913 |url=https://www.jssm.org/jssm-07-499.xml%3EFulltext# |access-date=26 July 2025}}</ref><ref>{{cite journal |last1=Carpesa, Felipe P. &, Motab, Carlos B. & Faria, Irvin E. |title=On the bilateral asymmetry during running and cycling - A review considering leg preference |journal=Physical Therapy in Sport |date=2010 |issue=11 |page=138 |url=https://www.researchgate.net/publication/47699656 |access-date=26 July 2025}}</ref>

==Health benefits==

=== Cardiovascular ===
While there exists the potential for injury while running (just as there is in any sport), there are many benefits. Some of these benefits include potential [[weight loss]], improved [[Circulatory system|cardiovascular]] and [[Respiratory system|respiratory]] health (reducing the risk of cardiovascular and respiratory diseases), improved cardiovascular fitness, reduced total blood [[cholesterol]], strengthening of bones (and potentially increased bone density), possible strengthening of the [[immune system]] and an improved self-esteem and emotional state.<ref>{{Cite news |url=http://well.blogs.nytimes.com/2009/11/04/phys-ed-why-doesnt-exercise-lead-to-weight-loss/ | title = Phys Ed: Why Doesn't Exercise Lead to Weight Loss? | date = 4 November 2009 | author = Gretchen Reynolds | work = [[The New York Times]] }}</ref> Running, like all forms of regular exercise, can effectively slow<ref>{{cite news |url=https://www.washingtonpost.com/wp-dyn/content/article/2008/01/28/AR2008012801873.html | title = Exercise Could Slow Aging of Body, Study Suggests | author = Rob Stein | newspaper = [[The Washington Post]] | date = 29 January 2008 }}</ref> or reverse<ref>{{cite web|url=https://news.bbc.co.uk/2/hi/health/270266.stm|title=Health - Exercise 'can reverse ageing'|work=bbc.co.uk}}</ref> the effects of aging. Even people who have already experienced a heart attack are 20% less likely to develop serious heart problems if engaging more frequently in running or any type of aerobic activity.<ref>{{Cite web |title=The science of exercise shows benefits beyond weight loss {{!}} Harvard Medical School Commentaries on Health - Credo Reference |url=https://search.credoreference.com/content/entry/hhphoh/the_science_of_exercise_shows_benefits_beyond_weight_loss/0 |archive-url=https://web.archive.org/web/20230404023050/https://search.credoreference.com/content/entry/hhphoh/the_science_of_exercise_shows_benefits_beyond_weight_loss/0 |archive-date=4 April 2023 |access-date=2025-08-21 |website=search.credoreference.com |language=en |url-status=live }}</ref>

Although an optimal amount of vigorous [[aerobic exercise]] such as running might bring benefits related to lower [[cardiovascular disease]] and life extension, an excessive dose (e.g., [[marathon]]s) might have an opposite effect associated with [[cardiotoxicity]].<ref>{{cite journal|doi=10.1016/j.mayocp.2015.08.001|pmid=26362561|title=Effects of Running on Chronic Diseases and Cardiovascular and All-Cause Mortality|journal=Mayo Clinic Proceedings|volume=90|issue=11|pages=1541–1552|year=2015|last1=Lavie|first1=Carl J.|last2=Lee|first2=Duck-Chul|last3=Sui|first3=Xuemei|last4=Arena|first4=Ross|last5=O'Keefe|first5=James H.|last6=Church|first6=Timothy S.|last7=Milani|first7=Richard V.|last8=Blair|first8=Steven N.|doi-access=free}}</ref>

=== Metabolic ===
{{Further|Neurobiological effects of physical exercise}}
{{multiple image|perrow = 1
|width1 = 250 |image1 = How to achieve your weight loss goals.jpg |caption1 = A U.S. Army soldier wearing [[sportswear]] runs to maintain his [[physical fitness|fitness]].
|width2 = 250 |image2 = Speedsuit.jpg |caption2 = A woman running in a [[speedsuit]].}}

Running can assist people in losing weight, staying in shape and improving body composition. Research suggests that the person of average weight will burn approximately 100 calories per mile run.<ref name="running.competitor.com">{{Cite web|url=http://running.competitor.com/2015/03/training/many-calories-running-burn_123951|title=How Many Calories Does Running Burn? {{!}} Competitor.com|date=2 March 2015|access-date=2 August 2016|archive-date=22 July 2016|archive-url=https://web.archive.org/web/20160722220440/http://running.competitor.com/2015/03/training/many-calories-running-burn_123951|url-status=dead}}</ref> Running increases one's [[metabolism]], even after running; one will continue to burn an increased level of calories for a short time after the run.<ref>{{Cite web|url=http://www.runnersworld.com/weight-loss/4-ways-running-is-best-for-weight-loss/slide/1|title=4 Ways Running is Best for Weight Loss|date=18 July 2016|access-date=2 August 2016}}</ref> Different speeds and distances are appropriate for different individual health and fitness levels. For new runners, it takes time to get into shape. The key is consistency and a slow increase in speed and distance.<ref name="running.competitor.com"/> While running, it is best to pay attention to how one's body feels. If a runner is gasping for breath or feels exhausted while running, it may be beneficial to slow down or try a shorter distance for a few weeks. If a runner feels that the pace or distance is no longer challenging, then the runner may want to speed up or run farther.<ref>{{Cite web|url=http://www.active.com/running/articles/how-fast-should-beginners-run|title=How Fast Should Beginners Run?|access-date=2 August 2016|date=February 2013}}</ref>

=== Mental {{anchor|Mental benefits}} ===
Running can also have psychological benefits, as many participants in the sport report feeling an elated, euphoric state, often referred to as a "[[runner's high]]".<ref>{{Cite journal
| last1 = Boecker
| first1 = H.
| last2 = Sprenger
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| title = The Runner's High: Opioidergic Mechanisms in the Human Brain
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|url=http://mediatum.ub.tum.de/doc/693893/document.pdf
| doi-access = free
}}{{Dead link|date=February 2022 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> Running is frequently recommended as therapy for people with clinical depression and people coping with addiction.<ref>{{cite web |url=http://www.freediets.com/endurance-training/the-benefits-of-running |title = Health benefits of running |publisher = Free Diets |access-date = 16 October 2008 |archive-date = 27 July 2009 |archive-url=https://web.archive.org/web/20090727095909/http://www.freediets.com/endurance-training/the-benefits-of-running |url-status = dead }}</ref> A possible benefit may be the enjoyment of nature and scenery, which also improves psychological well-being<ref>{{Cite journal
| last1 = Barton | first1 = J.
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| doi = 10.1021/es903183r
| title = What is the Best Dose of Nature and Green Exercise for Improving Mental Health? A Multi-Study Analysis
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}}</ref> (see [[Ecopsychology#Practical benefits|Ecopsychology § Practical benefits]]).

In animal models, running has been shown to increase the number of [[neurogenesis|newly created neurons]] within the brain.<ref name="pmid10195220">{{cite journal |vauthors=van Praag H, Kempermann G, Gage FH |title=Running increases cell proliferation and neurogenesis in the adult mouse dentate gyrus |journal=Nat. Neurosci. |volume=2 |issue=3 |pages=266–270 |date=March 1999 |pmid=10195220 |doi=10.1038/6368 |s2cid=7170664 }}</ref> This finding could have significant implications in aging as well as learning and memory. A recent study published in ''[[Cell Metabolism]]'' has also linked running with improved memory and learning skills.<ref>{{cite web|url=http://www.medicalnewstoday.com/articles/311152.php|title=Memory improved by protein released in response to running|website=Medical News Today|date=24 June 2016}}</ref>

Running is a great technique to lower inflammation, stress, anxiety, and depression. People with seasonal affective disorder benefit from running outside in warm, sunny weather. Running can improve mental alertness and sleep.<ref>{{cite journal | last1=Kalak | first1=Nadeem | title=Daily morning running for 3 weeks improved sleep and psychological functioning in healthy adolescents compared with controls. |url=https://www.sciencedirect.com/science/article/pii/S1054139X12001115| journal=Journal of Adolescent Health | year=2012 | volume=51 | issue=6 | pages=615–622 | doi=10.1016/j.jadohealth.2012.02.020 | pmid=23174473 | url-access=subscription }}</ref> Both research and clinical experience have shown that exercise can be a treatment for serious depression and anxiety even some physicians prescribe exercise to most of their patients.<ref>{{cite journal | last1=Greist | first1=John | title=Running as treatment for depression |url=https://dx.doi.org/10.1016/0010-440X%2879%2990058-0 | journal=Comprehensive Psychiatry | year=1979 | volume=20 | issue=1 | pages=41–54 | doi=10.1016/0010-440X(79)90058-0 | pmid=759100 | url-access=subscription }}</ref> Running can have a longer-lasting effect than anti-depressants.<ref>Alic, M. (2012). Mental health and exercise. In J. L. Longe, The Gale encyclopedia of fitness. Farmington, MI: Gale. Retrieved from https://search.credoreference.com/content/entry/galefit/mental_health_and_exercise/0</ref> The non-threatening environment offered by running generates a sense of achievement and belonging which helps with mental illness.<ref>{{Cite journal |last1=Morris |first1=Paul |last2=Scott |first2=Helen |date=2019-07-03 |title=Not just a run in the park: a qualitative exploration of parkrun and mental health |url=https://www.tandfonline.com/doi/full/10.1080/18387357.2018.1509011 |journal=Advances in Mental Health |language=en |volume=17 |issue=2 |pages=110–123 |doi=10.1080/18387357.2018.1509011 |issn=1838-7357|url-access=subscription }}</ref>

==Injuries==
{{Further|Running-related injuries}}

=== High impact ===
[[File:Bad-running-form.png|thumb|left|Person with a bad running form. Heel striking and leaning forward are some of the most common mistakes and cause of injuries among beginners.]]
Many injuries are associated with running because of its high-impact nature. Change in running volume may lead to development of [[patellofemoral pain syndrome]], [[iliotibial band syndrome]], [[patellar tendinopathy]], [[plica syndrome]], and [[medial tibial stress syndrome]]. Change in running pace may cause [[Achilles tendinitis]], [[gastrocnemius]] injuries, and [[plantar fasciitis]].<ref>{{cite journal|last=Nielsen|first=R.O|title=Classifying running-related injuries based upon etiology, with emphasis on volume and pace|journal=International Journal of Sports Physical Therapy|year=2013|volume=8|issue=2|pages=172–179|pmid=23593555|pmc=3625796}}</ref> Repetitive stress on the same tissues without enough time for recovery or running with improper form can lead to many of the above. Runners generally attempt to minimize these injuries by warming up before exercise,<ref name="Davis 1980 1590–95" /> focusing on proper running form, performing strength training exercises, eating a well balanced diet, allowing time for recovery, and "icing" (applying ice to sore muscles or taking an ice bath).

Some runners may experience injuries when running on concrete surfaces. The problem with running on [[concrete]] is that the body adjusts to this flat surface running, and some of the muscles will become weaker, along with the added impact of running on a harder surface. Therefore, it can be beneficial to change terrain occasionally – such as trail, beach, or grass running. This is more unstable ground and allows the legs to strengthen different muscles. Runners should be wary of twisting their ankles on such terrain. Running downhill also increases knee stress and should, therefore, be avoided. Reducing the frequency and duration can also prevent injury.

[[Barefoot running]] has been promoted as a means of reducing running related injuries,<ref name="Barefoot">{{cite news|url=http://www.post-gazette.com/pg/06157/696125-114.stm|title=Health Journal: Is barefoot better?|last=Parker-Pope|first=T|date=6 June 2006|work=[[The Wall Street Journal]]|access-date=6 November 2011}}</ref> but this remains controversial and a majority of professionals advocate the wearing of appropriate shoes as the best method for avoiding injury.<ref>{{cite news|url=https://www.nytimes.com/2009/08/30/business/30shoe.html|title=Wiggling Their Toes at the Shoe Giants|last=Cortese|first=A|date=29 August 2009|work=[[The New York Times]]}}</ref> However, a study in 2013 concluded that wearing neutral shoes is not associated with increased injuries.<ref>{{cite journal |last1=Nielsen |first1=Rasmus Oestergaard |last2=Buist |first2=Ida |last3=Parner |first3=Erik Thorlund |last4=Nohr |first4=Ellen Aagaard |last5=Sørensen |first5=Henrik |last6=Lind |first6=Martin |last7=Rasmussen |first7=Sten |year=2013 |title=Foot pronation is not associated with increased injury risk in novice runners wearing a neutral shoe: a 1-year prospective cohort study |url=http://bjsm.bmj.com/content/early/2013/06/12/bjsports-2013-092202.short?rss=1 |journal=British Journal of Sports Medicine |volume=48 |issue=6 |pages=440–447 |doi=10.1136/bjsports-2013-092202 |pmid=23766439 |s2cid=9880090|url-access=subscription }}</ref>

=== Chafing ===
[[File:Chafing.jpg|thumb|upright=0.75|Chafing of skin following a marathon run]]
Another common, running-related injury is [[Chafing (skin)|chafing]], caused by repetitive rubbing of one piece of skin against another, or against an article of clothing. One common location for chafe to occur is the runner's upper thighs. The skin feels coarse and develops a rash-like look. A variety of deodorants and special anti-chafing creams are available to treat such problems. Chafe is also likely to occur on the [[jogger's nipple|nipple]]. There are a variety of home remedies that runners use to deal with chafing while running such as band-aids and using grease to reduce friction. Prevention is key which is why form fitting clothes are important.<ref>{{Cite web|url=http://www.runnersworld.com/chafing/how-to-prevent-treat-chafing|title=How to Prevent & Treat Chafing|date=27 May 2015|access-date=2 August 2016}}</ref>

=== Iliotibial band syndrome ===
An iliotibial band is a muscle and tendon that is attached to the hip and runs the length of the thigh to attach to the upper part of the tibia, and the band is what helps the knee to bend. This is an injury that is located at the knee and shows symptoms of swelling outside the knee. Iliotibial band syndrome is also known as "runner's knee" or "jogger's knee" because it can be caused by jogging or running. Once pain or swelling is noticeable it is important to put ice on it immediately and it is recommended to rest the knee for better healing.<ref>Rothfeld, G. S., & Romaine, D. S. (2017). jogger's knee. In G. S. Rothfeld, & D. Baker, Facts on File library of health and living: The encyclopedia of men's health (2nd ed.). New, NY: Facts on File. Retrieved from https://search.credoreference.com/content/entry/fofmens/jogger_s_knee/0</ref> Most knee injuries can be treated by light activity and much rest for the knee. In more serious cases, arthroscopy is the most common to help repair ligaments but severe situations reconstructive surgery would be needed.<ref>Dupler, D., & Ferguson, D. (2016). Knee injuries. In Gale (Ed.), Gale encyclopedia of children's health: Infancy through adolescence (3rd ed.). Farmington, MI: Gale. Retrieved from https://search.credoreference.com/content/entry/galegchita/knee_injuries/0</ref> A survey was taken in 2011 with knee injuries being 22.7% of the most common injuries.<ref name="iup.klnpa.org">Newton, D. E. (2012). Running. In J. L. Longe, The Gale encyclopedia of fitness. Farmington, MI: Gale. Retrieved from https://search.credoreference.com/content/entry/galefit/running/0</ref>

=== Medial tibial stress syndrome ===
A more known injury is [[medial tibial stress syndrome]] (MTSS) which is the accurate name for shin splints. This is caused during running when the muscle is being overused along the front of the lower leg with symptoms that affect {{convert|2|to|6|in|cm|order=flip|round=5}} of the muscle. Shin splints have sharp, splinter-like pain, that is typically X-rayed by doctors but is not necessary for shin splints to be diagnosed. To help prevent shin splints it is commonly known to stretch before and after a workout session, and also avoid heavy equipment especially during the first couple of workout sessions.<ref>shinsplints. (2017). In G. S. Rothfeld, & D. Baker, Facts on File library of health and living: The encyclopedia of men's health (2nd ed.). New, NY: Facts on File. Retrieved from https://search.credoreference.com/content/entry/fofmens/shinsplints/0</ref> Also to help prevent shin splints do not increase the intensity of a workout more than 10% a week.<ref>Shin splints. (2017). In Harvard Medical School (Ed.), Health reference series: Harvard Medical School health topics A-Z. Boston, MA: Harvard Health Publications. Retrieved from https://search.credoreference.com/content/entry/hhphealth/shin_splints/0</ref> To treat shin splints it is important to rest with the least amount of impact on your legs and apply ice to the area. A survey showed that shin splints make up 12.7% of the most common injuries in running, with blisters being the top percentage at 30.9%.<ref name="iup.klnpa.org"/>

==Events==
[[File:2012 Olympics - Mens 10000 m.jpg|thumb|right|Competitors in the men's [[10,000 metres|10,000-metre run]] at the [[2012 Summer Olympics]].]]
Running is both a competition and a type of training for sports that have running or [[endurance]] components. As a sport, it is split into events divided by distance and sometimes includes permutations such as the obstacles in [[Steeplechase (athletics)|steeplechase]] and [[hurdles]]. Running races are contests to determine which of the competitors is able to run a certain distance in the shortest time. Today, competitive running events make up the core of the [[sport of athletics]]. Events are usually grouped into several classes, each requiring substantially different athletic strengths and involving different tactics, training methods, and types of competitors.

Running competitions have probably existed for most of humanity's history and were a key part of the [[ancient Olympic Games]] as well as the modern Olympics. The activity of running went through a period of widespread popularity in the United States during the [[running boom of the 1970s]]. Over the next two decades, as many as 25&nbsp;million Americans were doing some form of running or jogging – accounting for roughly one tenth of the population.<ref>{{cite web|url=http://www.motleyhealth.com/fitness/running-and-jogging-for-fitness|title=Health Benefits of Jogging and Running|work=MotleyHealth|date=14 July 2020 }}</ref> Today, road racing is a popular sport among non-professional athletes, who included over 7.7&nbsp;million people in America alone in 2002.<ref>USA Track & Field (2003). [http://www.usatf.org/news/specialReports/2003LDRStateOfTheSport.asp "Long Distance Running – State of the Sport."] {{Webarchive|url=https://web.archive.org/web/20080311181007/http://www.usatf.org/news/specialReports/2003LDRStateOfTheSport.asp |date=11 March 2008 }}</ref>

===Limits of speed===

[[Footspeed]], or sprint speed, is the maximum speed at which a human can run. It is affected by many factors, varies greatly throughout the population, and is important in athletics and many sports. Air resistance for top sprinters can take up to 5% of their energy.<ref name="r344">{{cite journal |last=Hill |first=A. V. |author-link=Archibald Vivian Hill |year=1928 |title=The air-resistance to a runner |journal=Proceedings of the Royal Society of London. Series B, Containing Papers of a Biological Character |publisher=The Royal Society |volume=102 |issue=718 |pages=380–385 |doi=10.1098/rspb.1928.0012 |issn=0950-1193 |doi-access=free}}</ref> 

The fastest human footspeed on record is {{cvt|44.7|km/h|m/s mph}}, seen during a 100-meter sprint (average speed between the 60th and the 80th meter) by [[Usain Bolt]].<ref>[http://berlin.iaaf.org/mm/document/competitions/competition/05/30/83/20090817081546_httppostedfile_wch09_m100_final_13529.pdf IAAF (International Association of Athletics Federations) Biomechanical Research Project: Berlin 2009.] {{webarchive|url=https://web.archive.org/web/20140514050117/http://berlin.iaaf.org/mm/document/competitions/competition/05/30/83/20090817081546_httppostedfile_wch09_m100_final_13529.pdf |date=14 May 2014 }}</ref>

=== Speed over increasing distance based on world record times ===
[[File:Human speed distance portrait.png|thumb|Maximum human speed [km/h] and pace [min/km] per distance]]
{| class="wikitable"
|-
! Distance metres
! Men m/s
! Women m/s
|-
| 100
| 10.44
| 9.53
|-
| 200
| 10.42
| 9.37
|-
| 400
| 9.26
| 8.44
|-
| 800
| 7.92
| 7.06
|-
| 1,000
| 7.58
| 6.71
|-
| 1,500
| 7.28
| 6.51
|-
| 1,609 ([[Mile run|mile]])
| 7.22
| 6.36
|-
| 2,000
| 7.02
| 6.15
|-
| 3,000
| 6.81
| 6.17
|-
| 5,000
| 6.60
| 5.87
|-
| 10,000 track
| 6.34
| 5.64
|-
| 10,000 road
| 6.23
| 5.49
|-
| 15,000 road
| 6.02
| 5.38
|-
| 20,000 track
| 5.91
| 5.09
|-
| 20,000 road
| 6.02
| 5.30
|-
| 21,097 [[Half marathon]]
| 6.02
| 5.29
|-
| 21,285 [[One hour run]]
| 5.91
| 5.14
|-
| 25,000 track
| 5.63
| 4.78
|-
| 25,000 road
| 5.80
| 5.22
|-
| 30,000 track
| 5.60
| 4.72
|-
| 30,000 road
| 5.69
| 5.06
|-
| 42,195 [[Marathon]]
| 5.69
| 5.19
|-
| 90,000 [[Comrades Marathon|Comrades]]
| 4.68
| 4.23
|-
| 100,000
| 4.46
| 4.24
|-
| 303,506 [[24-hour run]]
| 3.513
| 2.82
|}

===Types===
;Track
{{Main|Track running}}
[[File:Grayson running the 4x100.jpg|thumb|267x267px|A man running with a baton during a relay race.]]
Track running events are [[individual sport|individual]] or [[relay race|relay]] events with athletes racing over specified distances on an oval running track. The events are categorized as [[sprint (running)|sprints]], [[middle-distance running|middle]] and [[Long-distance track event|long-distance]], and [[hurdling]].

;Road
{{Main|Road running}}
Road running takes place on a measured course over an established road (as opposed to [[track running|track]] and [[cross country running]]). These events normally range from distances of 5 kilometers to longer distances such as [[half marathon]]s and [[marathons]], and they may involve scores of runners or wheelchair entrants.

;Cross-country
{{Main|Cross country running|Fell running|Trail running}}
Cross country running takes place over the open or rough terrain. The courses used for these events may include [[Poaceae|grass]], [[mud]], woodlands, hills, flat ground and water. It is a popular participatory sport and is one of the events which, along with track and field, road running, and [[racewalking]], makes up the umbrella sport of athletics.

;Vertical
{{Main|Fell running|Mountain running|Skyrunning|Trail running|Tower running}}
The majority of popular races do not incorporate a significant change in elevation as a key component of a course. There are several, disparate variations that feature significant inclines or declines. These fall into two main groups.

The naturalistic group is based on outdoor racing over geographical features. Among these are the cross country-related sports of [[fell running]] (a tradition associated with Northern Europe) and [[trail running]] (mainly [[ultramarathon]] distances), the running/climbing combination of [[skyrunning]] (organised by the [[International Skyrunning Federation]] with races across North America, Europe and East Asia) and the mainly trail- and road-centred [[mountain running]] (governed by the [[World Mountain Running Association]] and based mainly in Europe).

The second variety of vertical running is based on human structures, such as stairs and man-made slopes. The foremost type of this is [[tower running]], which sees athletes compete indoors, running up steps within very tall structures such as the [[Eiffel Tower]] or [[Empire State Building]].

===Distances===

====Sprints====
{{Main|Sprint (running)}}
[[File:Sina Schielke (192) wins the 100 metres race - ISTAF 2006 - Berlin, 3 September.jpg|thumb|upright=1.5|International-level women athletes competing in 100 m sprint race at [[ISTAF Berlin]], 2006]]

Sprints are short running events in athletics and track and field. Races over short distances are among the oldest running competitions. The first 13 editions of the [[Ancient Olympic Games]] featured only one event – the [[stadion race]], which was a race from one end of the stadium to the other.<ref name=Instone>Instone, Stephen (15 November 2009). [https://www.bbc.co.uk/history/ancient/greeks/greek_olympics_01.shtml#two The Olympics: Ancient versus Modern]. [[BBC]]. Retrieved 23 March 2010.</ref> There are three sprinting events which are currently held at the Olympics and outdoor World Championships: the [[100 metres]], [[200 metres]], and [[400 metres]]. These events have their roots in races of [[imperial measurement]]s which were later altered to metric: the 100&nbsp;m evolved from the [[100-yard dash]],<ref>[http://www.iaaf.org/community/athletics/trackfield/newsid=4661.html 100 m – Introduction]. [[IAAF]]. Retrieved 26 March 2010.</ref> the 200&nbsp;m distances came from the [[furlong]] (or 1/8 of a mile),<ref>[http://www.iaaf.org/community/athletics/trackfield/newsid=4677.html 200 m Introduction]. [[IAAF]]. Retrieved 26 March 2010.</ref> and the 400&nbsp;m was the successor to the [[440-yard dash]] or quarter-mile race.<ref name="400M"/>

At the professional level, sprinters begin the race by assuming a crouching position in the [[starting blocks]] before leaning forward and gradually moving into an upright position as the contest progresses and momentum is gained.<ref name="100 m – For the Expert">[http://www.iaaf.org/community/athletics/trackfield/newsid=4666.html 100 m – For the Expert]. [[IAAF]]. Retrieved 26 March 2010.</ref> Athletes remain in the same lane on the running track throughout all sprinting events,<ref name=400M>[http://www.iaaf.org/community/athletics/trackfield/newsid=4682.html 400 m Introduction]. [[IAAF]]. Retrieved 26 March 2010.</ref> with the sole exception of the 400&nbsp;m indoors. Races up to 100&nbsp;m are largely focused upon acceleration to an athlete's maximum speed.<ref name="100 m – For the Expert"/> All sprints beyond this distance increasingly incorporate an element of endurance.<ref>[http://www.iaaf.org/community/athletics/trackfield/newsid=4673.html 200 m For the Expert]. [[IAAF]]. Retrieved 26 March 2010.</ref> [[Human physiology]] dictates that a runner's near-top speed cannot be maintained for more than thirty seconds or so as [[lactic acid]] builds up, and leg muscles begin to be deprived of [[oxygen]].<ref name=400M />

The [[60 metres]] is a common indoor event and it an indoor world championship event. Other less-common events include the [[50 metres]], [[55 metres]], [[300 metres]] and [[500 metres]] which are used in some high and [[college athletics|collegiate]] competitions in the United States. The [[150 metres]], is rarely competed: [[Pietro Mennea]] set a world best in 1983,<ref name=150M>[https://news.bbc.co.uk/sport2/hi/athletics/8039407.stm Superb Bolt storms to 150m record ]. [[BBC Sport]] (17 May 2009). Retrieved 26 March 2010.</ref> Olympic champions [[Michael Johnson (athlete)|Michael Johnson]] and [[Donovan Bailey]] went [[Bailey–Johnson 150-metre race|head-to-head]] over the distance in 1997,<ref>Tucker, Ross (26 June 2008). [http://www.sportsscientists.com/2008/06/fastest-man-in-world.html Who is the fastest man in the world?] {{Webarchive|url=https://web.archive.org/web/20120523165116/http://www.sportsscientists.com/2008/06/fastest-man-in-world.html |date=23 May 2012 }}. The Science of Sport. Retrieved 26 March 2010.</ref> and [[Usain Bolt]] improved Mennea's record in 2009.<ref name=150M />

====Middle distance====
{{Main|Middle-distance running}}
Middle-distance running events are track races longer than sprints up to 3000 metres. The standard middle distances are the [[800 metres]], [[1500 metres]] and [[mile run]], although the [[3000 metres]] may also be classified as a middle-distance event.<ref>[http://www.britannica.com/EBchecked/topic/381174/middle-distance-running Middle-distance running]. ''[[Encyclopædia Britannica]]''. Retrieved 5 April 2010.</ref> The 880-yard run, or half-mile, was the forebear to the 800&nbsp;m distance and it has its roots in competitions in the United Kingdom in the 1830s.<ref name=IAAF800>[http://www.iaaf.org/community/athletics/trackfield/newsid=9389.html 800 m – Introduction]. [[IAAF]]. Retrieved 5 April 2010.</ref> The 1500&nbsp;m came about as a result of running three laps of a 500&nbsp;m track, which was commonplace in continental Europe in the 1900s.<ref name=IAAF1500>[http://www.iaaf.org/community/athletics/trackfield/newsid=9397.html 1500 m – Introduction]. [[IAAF]]. Retrieved 5 April 2010.</ref>

====Long distance====
{{main|Long-distance running}}
Examples of longer-distance running events are [[Long-distance track event|long-distance track races]], [[half marathon]]s, [[marathon]]s, [[Ultrarunning|ultramarathons]], and [[multiday races]].

==See also==
<!-- Please add related links to [[Outline of running]] -->
* [[Endurance running hypothesis]]
* ''[[The Horse in Motion]]''
* [[Level and incline running]]
* [[List of people killed while running]]
* [[Naruto run]]
* [[Outline of running]]
* [[Running energetics]]
* [[Skyrunning]]
* [[Speedrunning]]

==References==
{{Reflist|30em}}

== Further reading ==
* {{Cite journal|last1=Nilson|first1=Finn|last2=Lundkvist|first2=Erik|last3=Wagnsson|first3=Stefan|last4=Gustafsson|first4=Henrik|date=19 December 2019|title=Has the second 'running boom' democratized running? A study on the sociodemographic characteristics of finishers at the world's largest half marathon|journal=Sport in Society|volume=24|issue=4|pages=659–669|doi=10.1080/17430437.2019.1703687|issn=1743-0437|doi-access=free}}

==External links==
{{Sister project links |wikt=Running |commons=Running |b=no |n=no |q=Running |s=no |v=Running}}
* {{Cite EB1911|wstitle=Running}}

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please don't as they'll be removed immediately. The links are spam. Read up on Wikipedia:External Links for more info. -->

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