To prepare for the cross-country meet, a skier decides to significantly increase the amount of carbohydrates in his diet (a technique also known as carbohydrate loading). Why might this be beneficial to the cross-country skier? Check all that apply. Carbohydrates are used to build actin filaments in the myofibrils, which increases muscle bulk and performance. The liver can store copious amounts of ingested carbohydrates as glycogen, which can then be slowly broken down to release the glucose needed to fuel aerobic respiration. As long as oxygen is present, the glucose stored in the ingested carbohydrates can provide a steady stream of ATP, thus meeting the demands of prolonged periods of exercise. Eating more carbohydrates leads to more glycogen stores in muscles, which then equates to larger energy stores for short, explosive bouts of energy use.

As long as oxygen is present, the glucose stored in the ingested carbohydrates can provide a steady stream of ATP, thus meeting the demands of prolonged periods of exercise.

Explanation:

This is the strategy of  carbohydrate loading. it is nutritional-performance  techniques of storing carbohydrate as glycogen in livers and muscles, so that an athlete has enough supply of energy as ATPs  ( from the metabolism of glycogen as glucose) for  sustenance needed for  entire duration of  enduring  race.

For maximum performance in long distance races, energy in form of ATP is needed. The mechanisms of  substrate level, Kreb's Cycle,and oxidative  phosphorylation ensures that  stored glycogen in muscles and liver when converted to glucose produce enough steady ATPs for the muscles and therefore for sustenance. Oxygen is the main drive, as combustion fuel for these process to progress.It is the main electron acceptor for the ETC, that ensures steady supply of Energy  for  ATPs synthesis.

Therefore as long as there is supply of oxygen, stored CHO, can supply enough ATPs for the muscles to improve performance.  Thus if carbohydrate is stored as  glycogen in liver and muscles, and  there is no oxygen to burn it, no energy can be supplied.Thus the storage of glucose and availability of oxygen is essential.

this is a good question! i'll do some research and come back when i have the answer!