Adam C. Stewart
An earlier study found that progressive load lifts or repetitions lead to similar increases in strength and muscle size. A new study made the same comparison, but did you find the same results? This article describes the new study and when to use certain progressive overload strategies.
When to use certain progressive overload strategies
Note: This article was the cover of MASS Research Review for April 2024 and is a review of a recent study by Chaves et al. If you want more content like this, subscribe to MASS.
For years, I looked at my training chart every week, wondering how to achieve a progressive overload. Should I increase the load? Do I need to increase the repetitions? Do I need to add sets? Should I reduce the rest time? Do I have to lift the same weight but with my hat back on to make sure I set a new personal best? Sometimes I tormented myself so much over these details that I tried to implement them all in a training block, which was a surefire way to complicate things (Pro tip: even if it’s not “optimal”, choose a strategy, believe in it and stick to it at least a little). Despite my previous indecision, these are all equally legitimate strategies for getting a progressive overload or setting a PR (well, maybe not the hat adjustment). But is one better than the other?
An earlier intermediate study by Plotkin et al. (2-mass examination) found that trained women and men improved strength and muscle size to a (mainly) similar degree when comparing effort and repeated progression. However, the strength gains could have been slightly greater with the progression of the load compared to the progression of the repetition (+5.9%). This study recruited trained people, but tested strength on a Smith machine, although the participants were more accustomed to squatting with a free weight. Therefore, these results cannot be perfectly extrapolated to other populations or to a “specific strength” (test of the strength to the exercise trained). In addition, a study will hardly prevent people from worrying about the best way to exercise to maximize muscle growth. Fortunately, in a new design study within the subjects of Chaves et al. (1) again compared the evolution of effort and repetition for strength and Hypertrophy in a mixed Population, but this time they tested the specific strength.
Objective and assumptions
Objective
The main objective of the examined study was to compare the changes in the extension of the 1 RM legs and the cross section of the lateral muscle over 10 Weeks of training, which improved the lifted load or repetitions in untrained men and women.
Hypothesis
The researchers hypothesized that the progression of the load would lead to a greater increase in strength and muscle size than the progression in volume. They expected that the trajectory of the load would lead to greater changes in the volume load (series × repetitions × lifted load) over time, which would ultimately lead to greater gains in strength and size.
Study overview and training protocols
The researchers used an intra-subject longitudinal design in which all subjects completed each training condition. Specifically, all subjects performed unilateral leg extension training over the course of 10 weeks and achieved progressive overload on one leg by increasing the load while increasing repetitions on the other leg throughout the study. The subjects trained both legs two to three times a week for a total of 23 training sessions. The protocols and progression patterns specific to the issue are presented in Table 2.
Result
The researchers evaluated the cross-sectional area of the lateral muscle using Ultrasound and leg extension 1 rpm before and after the 10-week exercise intervention. The researchers also compared the lifted load (absolute and % of 1 rpm), the number of repetitions performed and the volume load between the conditions.
