Lactate Accumulation in Muscle and Blood during Submaximal Exercise
ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA
Pagination or Media Count:
Muscle and blood lactate concentration was studied in 10 healthy males during cycling exercise. For each subject the exercise intensity corresponding to a blood lactate concentration of 4 mmoll OBLA sub W was assessed by a stepwise increased exercise intensity protocol. In a second series of experiments the same protocol was performed but exercise was terminated at OBLA sub W and a muscle biopsy for subsequent analysis of lactate concentration was obtained from m. vastus lateralis. Biopsies were also taken at rest for histochemical determination of fiber type composition and capillary supply. The exercise intensity, which corresponded to OBLA sub W, averaged 159 117-216 W, equal to 65 range 55-84 of maximum oxygen uptake, and was found to be correlated to the capillary frequency of the exercising muscle r0.83, p0.01. Muscle lactate concentration averaged 6.9 range 2.1-12.6 mmolkg w.w. The muscle to blood lactate gradient as well as the change in blood lactate concentration prior to and 1 min post exercise were correlated to muscle lactate concentration r0.89, p0.001 and r0.71, p0.05. It is concluded that great individual variations in the muscleblood lactate gradient do exist during submaximal steady-state exercise, performed at a certain blood lactate level.
- Anatomy and Physiology