Effect of intensity of aerobic training on VO2max.
OBJECTIVE
To determine whether various intensities of aerobic training differentially affect aerobic capacity as well as resting HR and resting blood pressure (BP).


METHODS
Sixty-one health young adult subjects were matched for sex and VO2max and were randomly assigned to a moderate- (50% VO2 reserve (VO2R), vigorous (75% VO2R), near-maximal-intensity (95% VO2R), or a nonexercising control group. Intensity during exercise was controlled by having the subjects maintain target HR based on HR reserve. Exercise volume (and thus energy expenditure) was controlled across the three training groups by varying duration and frequency. Fifty-five subjects completed a 6-wk training protocol on a stationary bicycle ergometer and pre- and posttesting. During the final 4 wk, the moderate-intensity group exercised for 60 min, 4 d.wk the vigorous-intensity group exercised for 40 min, 4 d.wk and the near-maximal-intensity group exercised 3 d.wk performing 5 min at 75% VO2R followed by five intervals of 5 min at 95% VO2R and 5 min at 50% VO2R.


RESULTS
VO2max significantly increased in all exercising groups by 7.2, 4.8, and 3.4 mL.min.kg in the near-maximal-, the vigorous-, and the moderate-intensity groups, respectively. Percent increases in the near-maximal- (20.6%), the vigorous- (14.3%), and the moderate-intensity (10.0%) groups were all significantly different from each other (P < 0.05). There were no significant changes in resting HR and BP in any group.


CONCLUSIONS
When volume of exercise is controlled, higher intensities of exercise are more effective for improving VO2max than lower intensities of exercise in healthy, young adults.
Gormley
Shannan E
SE
The Wellness Institute and Research Center, Department of Exercise Science, Sport, Physical Education, and Recreation, Old Dominion University, Norfolk, VA 23529, USA. dswain@odu.edu
Swain
David P
DP
High
Renee
R
Spina
Robert J
RJ
Dowling
Elizabeth A
EA
Kotipalli
Ushasri S
US
Gandrakota
Ramya
R
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001794:Blood Pressure; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D009043:Motor Activity; D009119:Muscle Contraction / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology*; D055815:Young Adult