The relationship between changes in the muscle total adenine nucleotide poo
l (TAN = ATP + ADP + AMP) and IMP during and after 30 s of sprint cycling w
as examined. Skeletal muscle samples were obtained from the vastus laterali
s muscle of seven untrained men (23.9 +/- 2.3 yr, 74.4 +/- 3.6 kg, and 55.0
+/- 2.9 ml kg(-1) min(-1) peak oxygen consumption) before and immediately
after exercise and after 5 and 10 min of passive recovery. The exercise-ind
uced increase in muscle IMP was linearly related to the decrease in muscle
TAN (r = -0.97, P < 0.01), and the slope of this relationship (-0.83) was n
ot different from 1.0 (P > 0.05), indicating a 1:1 stoichiometric relations
hip. This interpretation must be treated cautiously, because all subjects d
isplayed a greater decrease in TAN compared with the increase in IMP conten
t, and the TAN + IMP + inosine + hypoxanthine content was lower (P < 0.05)
immediately after exercise compared with during rest. During the first 5 mi
n of recovery, the increase in TAN was not correlated with the decrease in
IMP (r = -0.18, P > 0.05). In all subjects, the magnitude of TAN increase w
as higher than the magnitude of IMP decrease over this recovery period. In
contrast, the increase in TAN was correlated with the decrease in IMP throu
ghout the second 5 min of recovery (r = -0.80, P < 0.05), and it was a 1:1
stoichiometric relationship (slope = -1.12). These data indicate that a sma
ll proportion of the TAN pool was temporarily lost from the muscle purine s
tores during sprinting but was rapidly recovered after exercise.