How many calories do you ACtually burn lifting???
Introduction
Study Reviewed: Predicting the energy expenditure of an acute resistance exercise bout in men and women. Lytle et al. (2019)
Key Points:
Study Overview: The study analyzed the caloric expenditure of lifting weights using a mixed-sex cohort performing seven exercises for 2-3 sets of 8-12 reps with 70% of predicted 1RMs.
Caloric Expenditure: The workout burned between 75-300+ calories, mainly depending on the volume load (sets × reps × load).
EPOC: Excess post-exercise oxygen consumption accounted for a minimal additional 7-8 calories.
Purpose and Research Questions
Purpose: Quantify the energy cost of a resistance training session and develop equations to predict energy expenditure.
Research Questions:
How many calories are burned during a full-body resistance training bout?
What equations can predict energy expenditure during resistance training?
Hypotheses: The study hypothesized that factors such as aerobic capacity, body composition, and total exercise volume would predict energy expenditure.
Subjects and Methods
Subjects: 52 healthy, active adults (27 men, 25 women) aged 20-58.
Methods:
Visit 1: Collection of body composition data and VO2max test.
Visit 2: Determination of 3-5RM for seven machine-based exercises.
Visit 3: Full-body resistance training session with gas exchange measurement for caloric expenditure estimation. A subsample underwent further testing for EPOC.
Findings
Caloric Burn: Men burned approximately twice the calories as women, but expenditure was similar when normalized to lean mass.
Regression Equation: Height, weight, age, sex, lean body mass, fat mass, and total volume load were significant predictors of energy expenditure.
EPOC: The additional calories burned post-exercise were minimal.
Interpretation
The study reveals that while lifting weights does burn calories, it is not as effective as traditional cardio. Volume load is the primary driver of caloric expenditure, but the total calories burned depend on the work performed. Changes in training volume impact caloric burn, but typically not enough to require significant dietary adjustments.
Application and Takeaways
Energy expenditure during lifting depends on total work done. For most, this won’t affect much outside the gym. Adjusting your nutrition based on changes in training volume are generally unnecessary unless you make significant changes.