Endurance and Speed DevelopmentTracy E. DockeryCaliforniaUniversity of Pennsylvania In many ways, sprinting and long distance running areat opposite ends of the athletic spectrum. Sprinting lasts a matter of secondsand endurance running goes on for hours.
When you look at a sprinter’s anddistance runner’s body you will notice a physical difference. Typically, a sprinter’s body has high muscledensity and is built for speed and power. A distance runner’s body tends to be comprised of long, lean muscle. Sprinters and endurance runners also differbased on physiological demands. Thisdiscussion will highlight key physiological requirements to be a successfullong distance runner and compare the requirements for endurance running to the physiologicalneeds associated with speed development.The body contains three muscle fiber types: slow-twitchred (type I), fast-twitch red (type IIa) and fast-twitch white (type IIb).
Dintiman and Ward (2011) state that slow-twitchred muscle fibers, or type I fibers, produce slow muscle contractions, haveslow twitch time, have high aerobic capacity, have low power output and arehighly resistant to fatigue (high endurance). This means long distance runners operate primarilythrough the use of their slow-twitch muscle fibers. According to Dintiman and Ward (2011) fast-twitchwhite muscles fibers, or type IIb fibers, produce fast contractions, have shorttwitch time, have high power output, have high anaerobic capacity and fatiguequickly. Sprinters, or speed developers, mainly utilize fast-twitch white musclefibers. Our body’s use different metabolic pathways to provideenergy during different running activities: the adenosine triphosate/creatine phosphatesystem (ATP/CP), lactic acid system (glycolytic system) and oxidativesystem. According to Berg (1982), the ATP/CPsystem providesenergy at a rapid rate for activities lasting 15 seconds or less.
The lacticacid system, provides energy for activities lasting fifteen seconds to twominutes. Lastly, the oxidative system provides energy for activities lastinglonger than two minutes. Hoefs(2017) states, endurance development utilizes the oxidative system about 95percent of the time and the glycolytic system about five percent. Short-distance sprints use primarily the ATP/CPsystem with the lactic acid system being used in middle-distance sprints likethe 400 meters.As stated by Dintiman and Ward (2011), the anaerobic threshold,also known as lactate threshold (LT) or lactate inflection point (LIP), refersto the point at which exercise intensity causes lactic acid to build up in theblood stream. When athletes engage indistance runs and stay below the anaerobic threshold, muscle lactate ismetabolized and little to no build-up occurs. This results in less fatigue and higher endurance.
During speed development, pace is increased,lactate is produced and blood lactate accumulates in the bloodstream causingthe athlete to fatigue more quickly.Running involves a complex number of physiologicalresponses. As shown in this paper, runningis much more than speed or distance. Allforms of running involve many processes in order to develop your athlete andtheir goals. It is amazing what the bodymust do in order to execute the simplest movements, or not so simple movements,like running.