Energy Economics of Marathon Runners Compared to 800m Runners

The purpose of this essay is to research and compare the energy economics of marathon runners and 800m runners, both during and after the event. It also looks at the difference in dietary preparation and the effect it has on the athlete’s energy systems. The different training regimes for each event will also be compared and the differences will be observed and interpreted.

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The purpose of this essay is to research and compare the energy economics of marathon runners and 800m runners, both during and after the event. It also looks at the difference in dietary preparation and the effect it has on the athlete’s energy systems. The different training regimes for each event will also be compared and the differences will be observed and interpreted.

The energy systems the human body uses can be broken down into three separate systems; Adenosine Tri-phosphate Phospho-creatine (ATP-PC), Lactic Acid, and Aerobic. The ATP-PC system “is used only for very short durations of up to 10 seconds. The ATP-PC system neither uses oxygen nor produces lactic acid if oxygen is unavailable and is thus said to be alactic anaerobic. This is the primary system behind very short, powerful movements like a golf swing or a 100 m sprint.” (http://en.wikipedia.org/wiki/Energy_systems#ATP-PC_System). In both events, ATP-PC system will be used at several times, even during a non explosive race such as a marathon, where it will be used during the first and last couple of hundred meters, as well as when the athlete may choose to accelerate past another competitor.  During the 800m race, ATP-PC is mostly all used during the first 10-15 seconds of a race and in the last 100m, when high energy demands peak.

The second energy system is the lactic acid (also called glycolytic or anaerobic) system which is capable of “releasing energy to resynthesise ATP without the involvement of oxygen and is called anaerobic glycolysis.” (http://www.brianmac.co.uk/lactic.htm). The lactic acid system generally only lasts for between 2 to 5 minutes, after which the aerobic energy system is used. Despite popular belief, lactic acid is not responsible for both the extreme burn in your muscles while exercising intensely or the soreness that comes after it, instead lactate is resynthesised in the liver, and forms glucose which your body uses as energy.  The burn athletes feel comes from the by-products of this reaction, which include carbon dioxide. Lactic acid plays a major role in 800m running events as lactic acid starts to build when an athlete hits 85-90% of their maximum heart rate, and will continue to build until the athlete finishes the race “For the women, the lactic acid energy contributions for the 400 m, 800 m and 1500 m averaged 62%, 33% and 17%, respectively. For the men, the lactic acid contributions averaged 63%, 39% and 20%, respectively” (http://www.ncbi.nlm.nih.gov/pubmed/10404496). Marathon runners on the other hand will generally only use the lactic acid system at the end of a race when they might speed up as most will run under the anaerobic threshold (the time when lactic starts to build).

The aerobic system is the third energy system to be used, and is the most influential energy system for marathon runners, providing up to 98% of the energy requirements. “The aerobic energy system utilises proteins, fats and carbohydrate (glycogen) for resynthesising ATP.”(http://www.brianmac.co.uk/energy.htm) While 800m runners do not use the aerobic system as a major energy source, it still plays a vital role in an athlete’s performance as a high aerobic threshold allows an athlete to recover faster and allows easier removal of lactate. This can be done through intense training to increase the aerobic threshold, allowing a higher work rate before lactic acid begins to be produced at an unmanageable level. As the aerobic system is used when the athlete is running at a steady medium pace, it is essential for marathon and other long distance sport athletes to build up a high threshold to allow them to work at a higher rate for longer.

All three energy systems need carbohydrates, proteins, and fat to function and it is essential for all athletes that a correct dietary regime is upheld. An 800m runner relies heavily on carbohydrates but a high amount of protein should also be consumed while training and carbohydrates should be stored before a race. A sample diet for an 800m athlete could be as seen in the appendix (Article A). A marathon runner needs a strong diet, but it is essential that a very high level of carbohydrates are consumed to avoid “hitting the wall”, an experience that occurs when the levels of glucose in the athletes bloodstream gets to low and it becomes hard for the athlete to function and think correctly. An example can be seen in the appendix as article B. It can be seen from the differences between the two dietary recommendations that an 800m runner has more balance between protein and carbohydrates as they have no risk if running low on glucose, while a marathon runner will focus mostly on loading as many carbohydrates into their system as possible.

The training sessions for the 800m and marathon runners are fairly similar; however there are some differences, with 800m runners focusing more on lactic acid tolerance than marathon runners, while marathon runners focus more on length and duration with a high aerobic threshold rather than the intensity of an 800m runner. An 800m training regime may look like this:

 Sat: Fartlek – 2’+3’+4’+3’+2’ off 2’ recovery + 2 x 5 x 100m Hill Sprints
Sun: 60’ easy to steady running + circuit training
Mon: 30’ easy to steady + abdominal and lower limb strengthening exercises
Tue: 30’ easy to steady + circuit or weight training
Wed: 45’ easy to steady + abdominal and lower limb strengthening exercises
Thu: 15’ threshold run + 5 x 200m at 1500m pace with 100m easy jog recovery
Fri: Rest

(http://www.completetrackandfield.com/800-meter.html)

While a marathon runners training regime may look like the following

MONDAY DAY OFF

TUESDAY Strength Endurance – 12km including 2km tempo then 5×2 minute hill repeats

WEDNESDAY Recovery Run – 5km

THURSDAY Tempo – 14km with 3×10 minute tempo efforts with a 2 minute recovery

FRIDAY Aerobic + Strides – 10km including 6×100m downhill strides

SATURDAY DAY OFF

SUNDAY Long Aerobic Run – 28km

(http://www.vaam-power.com/running_marathon/training-schedule.html)

As you can see, 800m runners focus on muscular strength (For the “Sprint kick” at the end of a race) and lactic tolerance, while marathon runners focus on long distance with brief spurts of acceleration and power to add to the endurance aspect. This requires a high anaerobic tolerance for 800m runners and an exceptionally high aerobic threshold for marathon runners.

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