Question

a well - trained, 130 - pound female marathon runner has just loaded up on a carbohydrate meal. she has the maximum amount of stored glycogen in her body as she begins a 26.2 mile marathon. as the runner depletes her stored glycogen, what will her body do so she can keep running? her muscle cells will begin using triglycerides as an energy source in aerobic respiration. her liver will start sending atp molecules through her bloodstream for her muscle cells to use. her lungs will work harder to provide the oxygen that her muscles need during glycolysis. her cells will switch to using fermentation, which produces more atp than aerobic respiration.

Explanation:

When glycogen stores are depleted during aerobic - activity like running a marathon, the body turns to other energy sources. Triglycerides can be used as an energy source in aerobic respiration. The liver doesn't send ATP through the bloodstream as ATP is produced within cells. Lungs work to supply oxygen for aerobic respiration in general, not specifically when glycogen is depleted. Fermentation produces less ATP than aerobic respiration.

Answer:

Her muscle cells will begin using triglycerides as an energy source in aerobic respiration.