Periodization refers to the manipulation of training variables over time to improve adaptations. For example, you might choose to increase the number of sets you’re doing from one week to the next. This would be considered periodization.

Periodization comes in different flavours. Linear periodization refers to an increase in intensity (aka weight on the bar) and a decrease in number of repetitions per set.

Reverse linear periodization is the exact opposite. Reps go up over the weeks as weight comes down.

Finally, undulating periodization is an umbrella term that encompasses changes in training variables that can go either up or down on a daily (DUP), weekly (WUP) or other timescale altogether.

That said, it’s not clear that changing training variables over time should inherently be better for strength gains vs just keeping them in their happy place. It also isn’t clear that a specific style of periodization would be better than another. Perhaps the benefits of periodization come simply from changing things up every now and then?

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Take-aways

1. Periodizing training probably leads to greater strength gains by allowing your training to be more specific.

2. Periodization should mostly be seen as a vehicle for specificity and keeping training interesting.

3. Undulating periodization may be a better standalone approach than linear periodization for strength.

4. For muscle growth, periodization plays next to no role.

   1. How you change your training over time likely has more to do with preference than with effectiveness.

This is where a recent meta-analysis by Moesgaard and colleagues comes in. In their meta-analysis, they compared non-periodized to periodized training, as well as comparing different periodization styles to one another.

This meta-analysis included 35 studies and looked at both 1RM strength and muscle growth.

First off; for 1RM strength, periodizing your training does seem to enhance gains by a small amount.

For muscle growth, on the other hand, periodizing made little to no difference.

Interestingly, linear periodization appeared to lead to greater 1RM strength gains than undulating periodization. No such finding was revealed for muscle growth.

Why?

The fact that periodization does improve strength gains but does not improve muscle growth might have you scratching your head.

Fortunately, this can be explained with one word: specificity.

A recent pre-print by Steele and colleagues argues that periodization is closer to being “myth-based” than being “evidence-based”. Indeed, they point out that many of the studies that have found a benefit to periodization for strength gains only did so because the group using a periodized approach trained with heavier loads leading up to the 1RM test.

In other words, the periodized group simply trained with greater specificity in the immediate pre-testing timeframe. By training heavier, they were able to see greater strength gains.

This likely explains most of the results here. Periodization should mostly be seen as a vehicle for training specificity (and something that keeps training fresh and interesting) rather than anything groundbreaking.

Importantly, an effectively periodized program will therefore employ elements of both linear (training becoming more specific as you near competition) and undulating (training is varied and interesting) periodization.