How many times should you train if your goal is strength?

What you will learn

How does training more frequently impact gains in muscular strength?
What types of people in terms of age and gender benefit the most from more weekly weight training sessions?
Does increasing training frequency help you to get stronger in both multi-joint (compound) and single-joint (isolation) exercises?
Does increasing training frequency help you to get stronger in both upper- and lower-body exercises?
Could you get even stronger by both increasing your training frequency and training to failure?

Summary

A review published in 2018 assessed the effect of one, two, three or four-plus weight training sessions per week on muscular strength gains. The researchers found an incremental increase in muscular strength gains with each additional resistance training session. However, whether the gains were driven by increased training frequency or training volume was unclear.¹

Introduction

Your muscles have four main properties:²

Strength (the amount of force a muscle can produce)
Size (a muscle’s diameter)
Endurance (a muscle’s ability to keep contracting against resistance)
Power (the amount of force a muscle can produce in combination with speed)

You can develop each muscle property by training in a specific way, which is explained in detail in my ebook.

For example, to develop muscular strength, you have to perform two to six sets per exercise, each consisting of two to six reps, using very heavy weights (more than 85% of your one-repetition maximum [1RM]). Because the weights are very heavy, you have to rest for two to five minutes between sets to allow for sufficient recovery. These are the standard recommendations of the National Strength and Conditioning Association (NSCA).²

Another standard recommendation is to work each muscle at least twice a week.² But what would be the optimal number of times to train per week if you wanted to get the best possible results?

This is what researcher Grgic J of the Institute of Sport, Exercise and Active Living (ISEAL) in Victoria University, Melbourne, and his colleagues set out to investigate. The team published their results in the journal Sports Medicine in 2018.¹

What did the team of researchers do?

Grgic and his colleagues reviewed 22 studies and used the findings to determine whether more frequent weight training sessions lead to greater gains in muscular strength. Across the studies, there were 912 participants. These included males and females; young, middle-aged and older individuals; and those who may or may not have trained before (the majority were untrained; only three studies included participants with experience of resistance training).¹

The team assessed the impact of more frequent weight training by measuring the change in 1RM for a given exercise before versus after the study. They also assessed the effects of other factors on muscular strength gains. The other factors included:¹

The ages of the participants
The gender of the participants
Whether the exercise used for the 1RM test was multi-joint or single-joint
Whether the exercise used for the 1RM test was for the upper or lower body
Whether or not the participants trained to failure

Results

Overall, the researchers found that muscular strength gains grew incrementally with each additional weight training session per week. However, when training volume (that is, the total weight lifted over a given period) was taken into account, training frequency did not have a significant impact, suggesting that the increase in muscular strength may have been driven by the increase in training volume as opposed to the increase in training frequency.¹

The researchers found a numerical improvement in muscular strength in all other tests, but most of these were not statistically significant, meaning that their results were not reliable.¹

Statistically significant effects on muscular strength were found in:¹

Younger adults but not in middle-aged and older adults, possibly due to younger adults having quicker recovery times
Females but not in males, the reason for which is unknown
Upper-body exercises but not in lower-body exercises
Multi-joint exercises but not in single-joint exercises

No significant effect of increasing training frequency was found on training to failure.¹

What does all this mean?

According to the results of this review:¹

You will get stronger if you train four times per week instead of three times, or if you train three times per week instead of two times. However, this might simply be because you are increasing your training volume
If you are female and/or young, you will see more strength gains than someone who is male and/or middle-aged
You will observe the greatest gains in strength in upper-body and multi-joint exercises
If you also train to failure, you will not see any additional gains in strength

References

Grgic J et al. Sports Med. 2018;48(5):1207–20.
Haff GG, Triplett NT, editors. Essentials of Strength Training and Conditioning, Fourth Edition. Illinois (USA): Human Kinetics; 2015. 752 pp.