Is the combination of training to failure and not to failure better than using one or the other alone?
Overview
What did they test? Researchers compared the number of repetitions, volume-load, time under tension (TUT), rating of perceived exertion (RPE), and muscle swelling between two different training protocols for the barbell preacher curl exercise. One protocol involved training to failure on all sets (TFAS) and the other protocol involved training to failure only in the last set of the exercise (TFLS).
What did they find? Training to failure in all sets resulted in a higher rating of perceived exertion (RPE) and greater time under tension (TUT). Training to failure only in the last set resulted in more total repetitions and volume load. There was not a significant difference in muscle swelling in response to each protocol.
What does it mean for you? Occasionally training to failure on the final set of an exercise, instead of all sets, may facilitate greater total volume load and a lower RPE without sacrificing a muscle swelling effect (e.g., pump).
What’s the problem?
Performing resistance training to failure is a common practice with the intent to achieve a more effective training stimulus. However, over the course of weeks of training, research on the topic has indicated this might not actually result in significantly more muscle growth or improvements in strength than stopping sets within a couple reps shy of failure 1. Stopping sets just shy of momentary failure can also result in less fatigue and a lower risk of injury which could facilitate more regular, productive training in the long run. However, proponents of training to failure can contend that taking sets to failure verifies a challenging set was completed and thereby an effective training stimulus was achieved. To this point, recent evidence from Robinson and colleagues 2 suggests greater hypertrophy occurs over the course of weeks from sets more proximal to failure than further away. Rather than consistently using one method or the other, perhaps a mix of training to failure and not training to failure is a more reasonable approach. This new study from Pedrosa and colleagues explored a mixed training method that could potentially offer benefits of both failure and non-failure training approaches.
Purpose
The purpose of the study was to compare the effects of training to failure in all four sets of the barbell preacher curl exercise versus training to failure in the last set only. The researchers looked at the impacts on the total number of repetitions completed, time under tension, ratings of perceived exertion, and muscle swelling.
