The effect of repeated muscle biopsy sampling on ATP and glycogen resynthesis following exercise in man.

The present study investigated the effect of repeated biopsy sampling on muscle adenosine 5'-triphosphate (ATP) and glycogen resynthesis following prolonged submaximal exercise. In one group of subjects (Ia, n = 7), biopsy specimens were obtained from the vastus lateralis immediately and 48 h after exhaustive one-legged cycling from both the non-exercised (control) and exercised legs. Additional samples were obtained from the exercised leg at 3, 10 and 24 h post-exercise. In a second group of subjects (Ib, n = 6), biopsy specimens were obtained immediately after exercise from both the control and exercised legs and at 48 h post-exercise from the exercised leg. All muscle biopsies were separated by a distance of 2.5 cm. In group Ia, ATP in the exercised leg was still lower after 48 h of recovery compared with the control leg (P <0.05), but complete restoration had occurred in group Ib (P > 0.05). Glycogen super compensation was not observed in group Ia. However, at the end of recovery, in group Ib glycogen in the exercised leg was 42 percent greater than in the control leg (P <0.01). Thus, following exhaustive dynamic exercise, repeated muscle biopsy sampling impaired ATP and glycogen resynthesis for several days, which may have been a result of the distance separating each biopsy site. The inhibition of ATP resynthesis appeared to be associated mainly with type II muscle fibres. The finding that, in contrast to muscle glycogen, ATP did not return to the basal level during the 48 h of recovery, suggests that the measurement of ATP may be a more sensitive measure of muscle damage than that of glycogen.