Effects of specific muscle training on VO2 on-response and early blood lactate.
The relationship between half time of the O2 uptake on-response (t1/2 VO2on, seconds) and early blood lactate accumulation (delta Lab, mmol.1(-1) at the onset of submaximal arm and/or leg exercise was the object of a cross-sectional study of sedentary subjects (S,n = 3), and kayakers (K, n = 8), and of a longitudinal study on 11 untrained subjects of specific arm vs. leg training. In supine arm cranking (W = 125 watts) S had an average t1/2 VO2on of 82 s and a delta Aab of 9.2 mmol.1(-1) compared to 47 +/- 7 s and 4 +/- 1.4 mmol.1(-1), respectively, for K. In longitudinal trainees shorter t1/2 VO2on was accompanied by lower Lab for the trained limbs. Specific limb conditioning in swimmers and runners resulted in shorter t1/2 VO2on. A linear relationship was observed between delta Lab and t1/2 VO2on having an intercept on the time axis at congruent to 20 s and a slope proportional to muscle mass. Trained muscles were grouped closest to the intercept indicating local acceleration of the rate of O2 transfer approaching the t1/2 VO2on for isolated perfused muscle at the onset of work. Since t1/2 VO2on, we conclude that factors distal to the capillary are specifically involved in the local training response.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D006801:Humans; D007773:Lactates / Q000097:blood*; D008875:Middle Aged; D009132:Muscles / Q000378:metabolism / Q000502:physiology*; D010101:Oxygen Consumption; D010725:Phosphocreatine / Q000378:metabolism; D005082:Physical Exertion; D012420:Running; D013178:Sports Medicine; D013550:Swimming
D007773:Lactates; D010725:Phosphocreatine; D000255:Adenosine Triphosphate