Resistance Exercise Energy Expenditure is Greater with Fatigue as Compared to Non-Fatigue

Christopher B. Scott and Conrad P. Earnest

Purpose: They retrospectively investigated data from two separate studies to estimate and compare aerobic and anaerobic exercise energy expenditure (EE) along with the aerobic recovery EE component for 1-set of resistance exercise. One study was completed using non-fatiguing lifts where the exercise was stopped before muscular failure. In another study muscular failure (fatigue) was the end point of all lifts. Work (weight lifted × upward vertical displacement) and all EE components were examined. Non-fatiguing lifts were carried out at 50% of a 1-RM for 7, 14 and 21 repetitions. Lifts to failure were carried out at ~37%, ~46%, ~56%, 70%, 80% and 90% of a 1-RM.

Conclusions: Lifting a weight to muscular failure can entail significantly greater aerobic, anaerobic and recovery EE components as compared to non-fatiguing lifting.

IN PLAIN ENGLISH: Exercising to the point of muscular failure (momentary muscular fatigue) is objective, measurable and meaningful. Not exercising to fatigue is subjective, hard-t0-measure (e.g., where do you halt the exercise?) and thus less effective.