What is the primary cause of fatigue during a power lift or short sprint lasting under 30 seconds?

The primary cause of fatigue during a power lift or short sprint lasting under 30 seconds is primarily due to running out of ATP (adenosine triphosphate) and CP (creatine phosphate) in the muscle cell. During high-intensity activities that are brief in duration, such as powerlifting or sprinting, muscles rely on the phosphagen energy system to generate immediate and explosive energy for contraction. This system uses stored ATP and CP as its primary energy sources.

Since these stores are limited, once they are depleted, the muscle's ability to sustain high-intensity efforts diminishes rapidly, leading to fatigue. This occurs well within the 30-second time frame typical of such powerful efforts. Understanding that ATP is the direct energy currency of cells and CP helps regenerate ATP indicates that when both are fully utilized and not replenished quickly enough, fatigue sets in.

In contrast, while dehydration, excessive lactic acid buildup, and inadequate warm-up may contribute to fatigue under different circumstances, they do not primarily cause it in the context of short-duration, high-intensity activities. For instance, lactic acid accumulation tends to be more associated with prolonged or sustained high-intensity efforts, while dehydration impacts overall performance in longer-term exercise rather than immediate energy bursts