When you lift a weight you can do 15 times, for 5 sets of 10 reps, your body’s energy burn depends mostly on how much muscle you use and how tired you get—not how fast you lift or how heavy the weight is relative to your max.
Scientific Claim
Resistance training with 15RM loads and 5 sets of 10 repetitions in healthy, resistance-trained men produces a metabolic response that is primarily driven by accumulated fatigue and muscle mass, not by exercise intensity or speed, as movement velocity was controlled and workload was standardized.
Original Statement
“The 15RM workload was adopted to allow the subjects to perform 5 sets of 10 repetitions in each exercise... The duration of the concentric and eccentric phases was also controlled (nearly 1 second each) to avoid the possible influence of the speed of movement on muscle tension and EE.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
The study controlled for movement speed and standardized workload, allowing causal inference that fatigue and muscle mass—not intensity or speed—are primary drivers in this protocol.
Evidence from Studies
Supporting (1)
The effect of Between-Set Rest Intervals on the Oxygen Uptake During and After Resistance Exercise Sessions Performed with Large- and Small-Muscle Mass
This study found that how big the muscles are and how tired they get during exercise matters more for burning energy than how fast or hard you lift—because they controlled the speed and weight, and still saw bigger muscles burn more energy.