Abstract

The accumulated O2 deficit (difference between estimated energy demand and actual O2 uptake) was determined during intense exhaustive exercise (2-7 min) in elite athletes, and its relationship with muscle buffer capacity, muscle enzymes and muscle morphology was examined. 5 oarsmen, 15 soccer players, and 14 distance runners ran, and 3 sprint cyclists cycled intensely to exhaustion (2-7 min). The oarsmen also performed exhaustive rowing. Blood lactate was measured immediately after several submaximal exercise bouts. A muscle biopsy was taken at rest from m. gastrocnemius of the soccer players and runners, and from m. vastus lateralis of the cyclists. The accumulated O2 deficit for the oarsmen, soccer players and runners during treadmill running was 47.3 (range: 29.6-62.4), 49.5 (34.3-73.7) and 51.9 (26.5-85.5) ml O2 equivalents (O2-Eq)/kg b.w., respectively, and it was 56.5 (47.5-73.2) ml O2-Eq/kg for the cyclists during cycling. O2 deficit was not related to blood lactate during submaximal exercise, muscle enyzme activity (citrate synthase, 3-hydroxyacyl-CoA-dehydrogenase, lactate dehydrogenase), number of muscle capillaries, ST fibres or muscle buffer capacity. The accumulated O2 deficit was 36 higher during rowing compared to running. The data suggest that the anaerobic energy production during intense exercise is related to the muscle mass involved. However, it appears that the anaerobic energy turnover is not determined by muscle fibre type distribution, muscle buffer capacity or muscle endurance capacity. Verf.-Referat