EFFECT OF REST INTERVAL ON OXYGEN CONSUMPTION FOLLOWING RESISTANCE EXERCISE
Mentor:Michelle Barrack-Gardner, Assistant Professor of Nitrution, Dietetics, and Food Science, California State University Northridge
The role of rest interval during resistance exercise (RE) on post-exercise oxygen consumption (VO2) has yet to be established, and may contribute to body mass management. PURPOSE: Determine the effect of rest interval length on VO2 following a full body RE session. METHODS: Eight men (age = 23.0 ± 0.76 yrs, body mass = 89.1 ± 17.8 kg) participated in this study. Subjects completed two trials of an 8 exercise resistance training regimen designed to target all major muscle groups. Lifts were performed at 3 sets of 8 repetitions at 65% 1RM. The short rest (SR) interval trial allowed for 30s rest between sets and 60s between exercises; the long rest (LR) interval trial allowed 90s and 180s, respectively. The measurement of VO2 began immediately post-exercise and was continued for 60 min. RESULTS: There was a twofold difference in time to completion between SR (24.7 ± 2.5 min) and LR (55.3 ± 0.9 min). Recovery period VO2 was greater in SR versus LR (4.9 ± 0.9 ml•kg-1•min-1 vs. 4.4 ± 0.5 ml•kg-1•min-1, p < 0.05), this increased rate occurring primarily in the first 20 min post-exercise. Calorie expenditure during recovery was higher in SR compared to LR (116.9 ± 10.7 vs. 107.8 ± 13.1 kcal, p < 0.05). Heart rate was also greater in SR compared to LR during both exercise (141.1 ± 20.1 vs. 124.0 ± 15.9 bpm, p < 0.05) and recovery (81.6 ± 10.7 vs. 68.3 ± 6.0 bpm, p < 0.05). CONCLUSION: A threefold decrease in rest interval resulted in a 9.7% increase in 60 min post-exercise VO2 and caloric expenditure. When body mass management is primary goal of exercise, short rest periods can be recommended for its ability to facilitate caloric expenditure.