Although energy is required throughout the entire body at all times, in sport we are interested in the relatively extreme demands generated by the neuromuscular system.  Various substrates are consumed during exercise (e.g. water) but in this section we will look at the role of adenosine triphosphate (ATP) and those processes used to replenish it.

ATP contains within it a significant amount of energy and is used to drive muscle contractions as well as coupling of neurological stimulus and muscle contraction (within ca²⁺ disinhibition).  As ATP is broken down when used (to release the energy needed) it must be continually reproduced in order to sustain exercise.  The amount of ATP in muscle cells never drops too low as this would cause cell death.  Instead, the level of activity begins to decline if insufficient ATP is being regenerated.  This process is called fatigue and is dealt with later in this section.


Suggested further reading for this section

'Exercise-Induced Metabolic Acidosis: Where do the Protons come from?', Robert A Robergs, Sportscience 5(2), 2001