Study: Individualize Training Frequency for Better Strength and Hypertrophy

A new study assessed strength and hypertrophy by having subjects train one leg with high frequency, and the other with low frequency.

Another interesting study is highlighting the idea that “more is not always more” when it comes to hypertrophy and strength training. There are multiple variables that should be considered when constructing well-balanced training programs, and the study covered below is once again showing that frequency and its benefits varies greatly between individuals.

In the new study published in the Journal of Strength and Conditioning Research, authors wanted to compare a subject’s unilateral 1-RM strength and muscular hypertrophy growth by training each leg differently: one got high frequency training and the other got low frequency. A key difference to this study compared to other frequency focused research was that authors utilized high and low frequency training for every individual, as opposed to splitting them into one group using one style of training (1).

This study was constructed as a follow-up to previous research the authors performed on frequency training (2). In their previous research, authors found that untrained men benefitted their strength and muscular hypertrophy equally from both low and high frequency training cycles, despite the high frequency group having higher total volume.

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Unilateral Frequency Training Research

Participants and Methods

In the study, 20 participants had each of their legs assigned to either a high frequency or low frequency training regimen. The high frequency leg was trained five times a week and the low frequency leg was trained either two or three times a week. To assess strength, subjects had their 1-RMs tested before the 8-week training intervention and then after using the leg extension machine. To record muscle cross-sectional area, researchers used an ultrasound to assess the vastus lateralis on each subject’s legs.

During the 8-week training intervention, subjects performed three sets of 9RM-12RM to muscular failure on the leg extension. They were granted 2-minutes to rest in-between each set, as this is a standard rest time for both strength and hypertrophy training.

Results and Suggestions

After the 8-week training intervention, subjects performed another 1-RM test and had their vastus lateralis cross sectional area assessed. Researchers found that there was a lot of variety between the results for muscular hypertrophy. For example, the high frequency group had an all-around higher total training volume, but there were no significant differences between the high frequency and low frequency training regimens. Authors point out that six individuals showed better results with high frequency, seven had better results with low frequency, and six experienced little to no change. 

Leg Extensions
Photo By Skydive Eric/Shutterstock

In respects to 1-RM strength, five subjects improved best with high frequency, three subjects with low frequency, and eleven had similar results. These mixed results were consistent with the researcher’s previous study that we noted earlier (2).

Practical Takeaways

One of the most interesting notes that authors made in this study was their hypothesis on a potential maximum resistance training threshold. In theory, this would be the volume cap one can hit to achieve maximal gains before hitting a wall of diminishing returns, aka putting in the work for no real benefit. The research is still a thin to draw any definitive conclusions on this hypothesis, but it does create some great food for thought.

This study helps further the knowledge of what we know on training frequency, strength, hypertrophy, and individual variability. Frequency is a variable that is highly related to an individual’s responsiveness to different training stimuli. Unlike volume and intensity, which are training variables that need to progressively increase over time for growth, frequency is more and more being suggested as not topping the training hierarchy of importance.

In fact, another study from May 2018 that we covered furthered this point by suggesting volume and intensity were far more indicative for success compared to frequency.

Now, this study did have its fair share of limitations, as it was performed on untrained individuals using only the leg extension in a short timeframe. Yet, this is another piece of literature that suggests frequency may not be as important as previously thought and it is highly individual. Authors suggest that the high amount of variability between high and low could be influenced by an individual’s responsiveness to recovery, their training age, and genetics.

The real takeaway, there is no one-size-fits-all when it comes to training frequency and maximal benefit. Some athletes might benefit better with more frequent exposure, while others will do better with less.


1. Damas, F., Barcelos, C., Nóbrega, S., Ugrinowitsch, C., Lixandrão, M., & Santos, L. et al. (2019). Individual Muscle Hypertrophy and Strength Responses to High vs. Low Resistance Training Frequencies. Journal Of Strength And Conditioning Research, 33(4), 897-901.

2. Barcelos C, e. (2019). High-frequency resistance training does not promote greater muscular adaptations compared to low frequencies in young untrained men. – PubMed – NCBI . Retrieved 1 April 2019.

Feature image from Skydive Eric/Shutterstock