Anaerobic ATP production and accumulated O2 deficit in cyclists
Green, S.; Dawson, B.T.; Goodman, C.; Carey, M.F.
Medicine and Science in Sports and Exercise 28(3): 315-321
1996
ISSN/ISBN: 0195-9131 PMID: 8776220 Document Number: 456383
Anaerobic ATP production in skeletal muscle and the accumulated oxygen deficit (O-2D) incurred during an exhaustive cycle bout (duration = 173 +- 24 s; intensity = 112 +- 3% ovrhdot VO-2peak), were determined in 10 male cyclists (mean +- SD: ovrhdot VO-2peak = 69.8 +- 4.2 ml cntdot kg-1 cntdot min-1). Anaerobic ATP production (mmol cntdot kg-1 d.w.) was determined from changes in lactate, phosphocreatine, ATP, and ADP in vastus lateralis. Muscle buffer value and the activities of glycogen phosphorylase (PHOS), phosphofructokinase and citrate synthase (CS) were also determined. The anaerobic ATP production determined from measured muscle metabolites was 202.7 +- 46.9 mmol cntdot kg-1 d.w. and was correlated (P ltoreq 0.05) with muscle buffer value (r = 0.81), PHOS (r = 0.69) and the ratio of PHOS to CS activity (r = 0.77). The O-2D was 55.2 +- 10.3 ml O-2 Eq cntdot kg-1, but was not correlated (P gt 0.05) with anaerobic ATP production (r = -0.38), buffer value (r = -0.50) or PHOS (r = -0.39). These latter findings could be explained by error in measuring the O-2D and/or muscle anaerobic ATP production in well-trained cyclists.