Effect of 6 d of exercise training on responses to maximal and sub-maximal exercise in middle-aged men.
Nine sedentary men (53 +/- 3 yr) were studied before and after 6 d of endurance exercise training to determine the effects on maximal oxygen uptake (VO2max), and on the heart rate, blood pressure, and metabolic responses to a standard bout of steady-state sub-maximal exercise. The subjects exercised approximately 1 h.d-1 at about 68% of VO2max. The 6-d protocol elicited no improvement in VO2max (2.50 +/- 0.14 before vs 2.58 +/- 0.15 l.min-1 after training). Heart rates were significantly lower by 5 to 8 b.min-1, systolic blood pressures were reduced by 16 to 19 mm Hg, and blood lactate concentrations were 25 to 35% less at the same exercise intensities (60, 70, and 80% of VO2max) after 6 d of exercise. Rate pressure product was about 15% lower at the same exercise intensity after 6 d of training (P less than 0.05). The respiratory exchange ratio during submaximal exercise was 0.02 to 0.04 units lower (P less than 0.05; P less than 0.01) after 6 d of exercise, indicating a shift in substrate utilization favoring fat oxidation. These findings suggest that short-term endurance training can induce heart rate, blood pressure, and metabolic adaptations to sub-maximal exercise before there is a significant increase in VO2max in sedentary, middle-aged men who are capable of vigorous exercise.
Rogers
M A
MA
Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110.
Yamamoto
C
C
Hagberg
J M
JM
Martin
W H
WH
Ehsani
A A
AA
Holloszy
J O
JO
D001794:Blood Pressure; D006339:Heart Rate; D006801:Humans; D007773:Lactates / Q000097:blood; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D005082:Physical Exertion
D007773:Lactates