Predicting Energy Expenditure of an Acute Bout of Resistance Exercise in Men and Women

Energy expenditure from resistance exercise (RE) is an important consideration for exercise prescription, yet prediction models are lacking. PURPOSE: To develop regression equations to predict energy expenditure (kcal) for RE involving each major muscle group using commonly measured demographic & exercise variables as predictors. METHODS: Fifty-two healthy, active subjects (27 men, 25 women, age 20-58 yrs, height 174.1 ± 10.5 cm, weight 188.7 ± 42.6 kg, VO2max 36.8 ± 9.2 ml/kg/min) were strength tested to determine their 3-5 repetition max (RM) on commercial pneumatic RE equipment 1 week prior to their experimental RE bout. Body composition was assessed using DEXA. For the experimental RE, a warm-up set followed by 2-3 sets of 8-12 reps at 60-70% predicted 1RM were performed for each exercise. Each set started every two minutes. Exercises progressed order: leg press, chest press, leg curl, lat pull, leg extension, triceps extension, biceps curl. VO2 was measured continuously throughout the RE bout via automated metabolic cart. Total exercise volume (TV) was calculated as sets*reps*weight lifted. Multiple Linear Regression (Stepwise Removal) was used to determine the best model to predict kcal consumption based on the highest adjusted R2 and least amount of variance inflation. RESULTS: Total net kcal expenditure for the entire RT bout was 133.6 ± 57.6 kcal (men = 167.7 ± 51.6 & women = 91.5 ± 32.0) with a total kcal cost of 23.4-34.9 per exercise. Large muscle group/multi-joint exercises had the highest total kcal expenditures. The prediction equation was as follows (p2=0.773): Total Net Kcal = 0.874*(HT cm) - 0.596*(AGE yrs) - 1.016*(FAT MASS kg) + 1.638*(LEAN MASS kg) + 2.461*(TV [sets x reps x wt] kg x 10-3) - 110.742 CONCLUSIONS: Energy expenditure for a total RE bout and for specific RE exercises can be reasonably estimated in adult men and women using commonly measured demographic and RE variables. With regards to fitness, performance, and weight management, these equations will aid practitioners and exercising adults in documenting kcal expenditure from RE