Question

Before heading to the Tour de France a cyclist had a muscle biopsy in his leg. The tests revealed that the dominant muscle fibers were low in myosin ATPase activity and anaerobic enzymes, high in capillary density and myoglobin content. For this athlete to maintain force production, what direct change (in the cytosol) in ion concentration must occur?

Answer 1

Specifically the Type I muscles are the one that is mentioned here as these type of muscle fiber are seen more in athlete's and are low in myosin activities . Type I muscle fiber is dominant in this athlete. In this athlete oxidative phosphorylation is the main source for the energy in these muscle . So this kind of oxidative phosphorylation will specify acts as the major source in the ATP generation of the individual and is much slower than that of glycolysis, but when we consider their efficiency these muscle fibres. Specifically the Decrease in the extracellular potassium concentration in the athlete will help him to maintain the force production in his body . Whenever the muscles of the athlete contract they will lose some potassium ions and is Specifically transported outside the Specific cell into the surrounding interstitial fluid of these cell . Reduction in the intramuscular potassium ions as welll as an increased extracellular potassium will finally cause fatigue in the athlete . It will mainly underly on the length of the muscles as well as the shortening velocity of the muscles of the athelete.