Journal
EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY
Volume 88, Issue 6, Pages 580-587Publisher
SPRINGER
DOI: 10.1007/s00421-002-0743-9
Keywords
chronic obstructive pulmonary disease; oxidative enzymes; oxygen transport - muscle
Categories
Ask authors/readers for more resources
We studied 21 patients with chronic obstructive pulmonary disease aged [mean (SD)] 63 (10) years, with a mean forced expiratory volume in 1 s of 40 (6)% and a peak oxygen uptake of 67 (11)% of predicted values. Patients trained for 6 weeks on a cycle ergometer at high work-rates (WR). Near-infrared spectroscopy was used to obtain the time-constant of the deoxygenation recovery signal (tauHbO(2)) during three constant WR exercise tests, one below and two above the lactic acidosis threshold (theta(L)). Glycolytic and oxidative enzymes and lactate concentrations were assessed in muscle biopsies. The tauHbO(2) decreased significantly in all three constant WR tests: -18 (24)s, -20 (23) s and -13 (22) s, respectively. Endurance time increased in the higher WR tests, by 5.7 (4.8) min and 3.6 (2.7) min, respectively. The activity of citrate-synthase (CS) and creatine-kinase changed significantly from 20 (10) to 30 (13) mumol.min(-1).g(-1) 9 and from 3.825 (950) to 3.402 (526) mumol.min(-1).g(-1) respectively. Training also improved significantly the mean response time of the on-transient of oxygen uptake (tau'(V) over dotO(2)) of the below-theta(L) test. We found significant correlations between changes in CS and changes tauHbO(2), tau'(V) over dotO(2) and endurance time. We conclude that leg training accelerates the speed of re-oxygenation of the vastus lateralis muscle after exercise. This improvement is correlated to changes in the oxidative enzymes.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available