The Norwegian experiment and training frequency

written by Philip Stefanov  |  MARCH 2, 2021

An interesting experiment came out a few years ago. In the study, the Norwegian school of sports sciences set out to examine the effects of high-frequency training when compared to a low-frequency protocol.

(What’s great about this study is that the subjects were all highly trained, and the common response of some people, “Those are just newbie gains!”, doesn’t apply.)

Each of the participants had trained for competitive powerlifting for at least one year. All of them also competed in the national Norwegian IPF powerlifting competitions within the previous six months. There were 16 participants between the ages of 18 and 25. Thirteen were men and three were women. They were pretty strong, too:

  • The average squat was 350 lbs (158 kilos)
  • The average bench press was 275 lbs (125 kilos)
  • The average deadlift was 440 lbs (200 kilos)

Their coach, Dietmar Wolf, set up the 15-week training program with the same exercises, training volume, and intensity for everyone. The 16 participants were split into two groups:

One group had three training sessions per week and the other group trained six days a week. For the volume to be equated, the low-frequency group had to do twice as much work in each workout when compared to the 6-day group. After fifteen weeks, the results were interesting:

The high-frequency group increased their squat and bench press nearly twice as much when compared to the low-frequency group (11±6 percent vs. 5±3 percent, and 11±4 percent vs. 6±3 percent, respectively). There were no significant differences in strength gains for the deadlift (9±6 percent vs. 4±6 percent).

The researchers also looked at changes in muscle mass for the vastus lateralis and quadriceps as a whole. The average increase for the high-frequency group was nearly ten percent in the vastus lateralis and five percent in the quad as a whole.

On the other hand, the low-frequency group didn’t experience any significant hypertrophy.

This study, though it never got published in any peer-reviewed journal, led many people to believe that more frequent training = more gains. And while this may very well be the case for strength improvements, it’s not as simple for muscle growth.

In a recent meta-analysis, Brad Schoenfeld and colleagues concluded that, as long as training volume is equated, training more frequently doesn’t lead to faster progress in the gym. Still, there’s one caveat:

Sure, training volume is the main driver for muscle growth, and more is better (to a point), but training frequency is a valuable tool we need to take advantage of. Why? Volume allocation.

Say, for example, that you are currently doing 16 sets for your back each week, all crammed into one workout. Once you’re done with the first half, you’re probably feeling fatigued which means you either need to reduce the weight you are lifting or do fewer repetitions.

Now, if you were to split these 16 sets across two training sessions, you would train your back more effectively because you would have some recovery time (two to four days) between the first and second half. This would allow you to use more weight on each set, maintain good form, and do more repetitions.

Thank you for reading! Until next week,


P.S. You can read some of my thoughts on training for strength and muscle mass.


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