Ultimate test puts body through its paces

To break the two-hour barrier for the marathon, Eliud Kipchoge will have to summon his reserves of mental strength.

During a marathon, every part of the body has to perform at an extreme level, hour after hour. For example, the heart has to pump four times the amount of blood needed than at its usual resting rate.

Heat and sweat are produced by a runner to keep body temperature at between 36 and 38 degrees C.

A runner will typically produce three to six liters of sweat during a marathon. Proper hydration is crucial. Without it, heat loss will be reduced, heart rate will rise and fatigue set in. Energy is also essential to fuel the body, with glucose being the most efficient source.

However, the body can store only limited amounts of glucose, and without gels or sports drinks is likely to need to rely on fat after about 30 kilometers. But fat is a less-efficient fuel, hence many runners experience hitting "the wall".

During a marathon, athletes take about 40,000 strides. Each one places stress on the joints and muscles, leading to soreness and potential cramp.

Elite runners train to ensure they have a higher maximum oxygen capacity, so that more oxygen gets to their muscles.

Such runners operate at 75 percent of their maximum oxygen capacity, compared with recreational runners, who can only operate at 60 percent.

Elite athletes also train to ensure they have more efficient biomechanics, leading to improved running economy and a lower risk of injury. They even have more efficient tendons that store and release energy in a similar way to springs.

Anatomy is also a crucial consideration for such runners. Athletes with a smaller stature and lower muscle mass are more suited to distance running than those with a more muscular build.

Ineos 1:59 Challenge

(China Daily Global 10/10/2019 page2)