how does the cause of fatigue in intense exercise differ fro

how does the cause of fatigue in intense exercise differ from that in low intensity, long duration exercise?

Solution

Reduction in the ability of a muscle to generate force is called muscle figue. Both intense and prolonged exercise can leads o fatigue. The causes of fatigue in intense exercise differ from that in low intensity, long duration exercise.

Causes:

Glycogen Depletion: Low intensity, long duration exercise requires sustained energy provision to maintain muscle contraction and is accomplished through the continual production of ATP. During excersise the stored glyogen in the muscles gets converted into energy (ATP production). In intense excercise the ATP production rate will be reduced compared to the ATP utilization rate results in the accumulation of metabolic by-products such as hydrogen ions, inorganic phosphate, AMP, ADP and IMP. Intermittent or lower-intensity exercise uses up stored glycogen much more slowly, delaying fatigue.

Hormonal changes:

During intense excersise, working muscles release tryptophan, an amino acid that stimulates serotonin production and decreased cortisol, preinlmmatory hormone associated with sleepiness and lethargy, increases during prolonged exercise. During high-intensity exercise, the normal equilibrium between the uptak and intake of potassium rom recruited muscle and uptake by inactive muscle fibers is lost resulting in a continual increase of extracellular potassium until the onset of fatigue. Ratio of intracellular and extra cellular proteins cross the sarcolemma alter the resting membrane potential and decrease sarcolemma excitability.Reduced excitability contributes to reduced calcium release by the sarcoplasmic reticulum (a process that requires ATP) and a consequent reduction in the force of muscle contraction. Environmental conditions also has an influence on fatigue durig high intensity excersises

Decreased Creatine Phosphate

Creatine phosphate is an important molecule powering skeletal muscle during exercise. Creatine phosphate\'s reforms ATP, The action of creatine phosphate ensures that ATP does not fall below 70% of the preexercise level. During prolonged exercise, levels of creatine phosphate decline, causing the muscles to receive less energy and become fatigued.