Smith, J. C., Kjeisers, N. L., Kanteebeen, M., Williams, C. S., Hughes, J. E., & Hill, D. W. (1998). Metabolic responses during repeated bouts of cycle ergometer exercise at critical power. Medicine and Science in Sports and Exercise, 30(5), Supplement abstract 212.

It is often assumed that the energy demands in a single bout of interval exercise will be the same across repetitions. Ss (N = 7) were tested for physiological and performance factors and then performed five 6-minute repetitions at critical power with 2-minute recovery periods.

Across the five repetitions, there were no differences in peak VO2 or VO2 kinetics. However, the aerobic contribution increased in a linear fashion across repetitions.

Implication. Interval training employing predominantly aerobic work increases the demands for aerobic energy on each successive repetition. For specific training effects to be achieved, a coach has to determine whether the early or late repetitions match event-specific demands and emphasize those trials. To achieve the greatest amount of specific effects variable interval sets might have to be used.

Return to Table of Contents for this issue.