EFFECT OF INTERVAL VERSUS CONTINUOUS TRAINING ON AEROBIC AND ANAEROBIC VARIABLES

Abstract

Interval training is used regularly by athletes to improve aerobic and anaerobic fitness and performance. It is used less frequently, however, by non-athletes as a means of improving important measures of aerobic and anaerobic fitness that may improve physical performance in both athletic and non-athletic settings. PURPOSE: The purpose of this study was to compare a typical, continuous training program with a higher intensity, interval training program in the development of aerobic and anaerobic fitness in young adults. METHODS: Forty-two volunteers were randomly assigned to a continuous training (CT) group or an interval training (IT) group. A separate control group was formed from volunteers who were currently not engaged in continuous or interval training. Both training groups trained an average of 3 times per week for ten weeks starting the first week at 70% of VO2max for 30 min, increasing to 75% VO2max for 35 min the fifth week, and increasing to 80% VO2max for 40 min the eighth week. The CT group maintained a constant intensity throughout each training session. The IT group completed a similar volume of work per session but varied the intensity within each session from 120–150% VO2max during the work intervals to 30–40% VO2max during the relief intervals. The training program was preceded and followed by a series of tests of maximal oxygen consumption (VO2max), a timed anaerobic treadmill test (run at 6 or 8 mph at 20% grade), a timed 50-meter sprint, and maximum isokentic strength measurements of leg extension and leg flexion at 60°·s−1 and 300°·s−1. RESULTS: The training resulted in a significant improvement (P < .01) in the VO2max, anaerobic treadmill test and sprint time in both the IT and CT group. The IT group also showed significant improvement (P < .01) over the CT group and controls in anaerobic treadmill time and sprint time. Among the three groups, only IT group showed significant improvement in the 300°·s−1 leg extension and leg flexion tests (P < .01). The CT and control group showed no significant improvement in any of the isokinetic tests. CONCLUSION: The results of this study indicate that interval training demonstrates the same aerobic fitness benefit as continuous training. Additionally, interval training shows significantly greater changes in anaerobic treadmill time and sprint time than continuous training in young adults. It should be noted, however, that participants in the IT group perceived the exercise at a higher level of exertion than the CT group and were more likely to discontinue exercise due to lower limb discomfort.