Local and systemic effects on blood lactate concentration during exercise with small and large muscle groups.
To evaluate the relationship between lactate release and [lac](art) and to investigate the influence of the catecholamines on the lactate release, 14 healthy men [age 25+/-3 (SE) year] were studied by superimposing cycle on forearm exercise, both at 65% of their maximal power reached in respective incremental tests. Handgrip exercise was performed for 30 min at 65% of peak power. In addition, between the tenth and the 22nd minute, cycling with the same intensity was superimposed. The increase in venous lactate concentration ([lac](ven)) (rest: 1.3+/-0.4 mmol.l(-1); 3rd min: 3.9+/-0.8 mmol.l(-1)) begins with the forearm exercise, whereas arterial lactate concentration ([lac](art)) remains almost unchanged. Once cycling has been added to forearm exercise (COMB), [lac](art) increases with a concomitant increase in [lac](ven) (12th min: [lac](art), 3.2+/-1.3 mmol.l(-1); [lac](ven), 5.7+/-2.2 mmol.l(-1)). A correlation between oxygen tension (P(v)O(2)) and [lac](ven) cannot be detected. There is a significant correlation between [lac](art) and norepinephrine ([NE]) (y=0.25x+1.2; r=0.815; p<0.01) but no correlation between lactate release and epinephrine ([EPI]) at moderate intensity. Our main conclusion is that lactate release from exercising muscles at moderate intensities is neither dependent on P(v)O(2) nor on [EPI] in the blood.
Chudalla
R
R
Sports and Exercise Physiology, Medical School Hannover, Carl-Neubergstrasse 1, 30625 Hannover, Germany.
Baerwalde
S
S
Schneider
G
G
Maassen
N
N
D000328:Adult; D001642:Bicycling / Q000502:physiology; D001784:Blood Gas Analysis; D015444:Exercise / Q000502:physiology*; D005542:Forearm / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D009638:Norepinephrine / Q000097:blood; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology; D013564:Sympathetic Nervous System / Q000502:physiology; D014891:Weight Lifting / Q000502:physiology
D019344:Lactic Acid; D010100:Oxygen; D009638:Norepinephrine