Muscle Growth: Systematic Review And Meta

This meta is an updated and expanded meta looking at the same question the Schoenfeld (2017) meta examined: the impact of intensity on muscle growth. This meta split loading zones into “high load” (8RM or heavier), “moderate load” (9-15RM), and “low load” (lighter than 15RM). It found that hypertrophy was similar in all three loading zones.

Cluster sets and traditional sets seem to produce similar hypertrophy. Another recent meta-analysis by Jukic and colleagues comparing traditional sets with both cluster sets and rest redistribution sets had similar findings.

Regional hypertrophy (greater growth in some regions of a muscle compared to other regions) can occur, and seems to be the rule, rather than the exception. Of the 14 studies included in this review, inhomogenous hypertrophy was observed in 13 of them.

We have fairly consistent evidence indicating that training through a longer range of motion is beneficial for lower body hypertrophy (quad growth, specifically). There haven’t been many studies investigating upper body hypertrophy yet. This study was previously discussed in more depth in MASS.

Step-up, hip thrust, and deadlift variations do a pretty good job of eliciting high levels of glute EMG activity. Lunges and squat variations are also pretty good.

“Isometric training at longer muscle lengths produced greater muscular hypertrophy when compared to equal volumes of shorter muscle length training. Ballistic intent resulted in greater neuromuscular activation and rapid force production. Substantial improvements in muscular hypertrophy and maximal force production were reported regardless of training intensity. High‐intensity (≥70%) contractions are required for improving tendon structure and function. Additionally, long muscle length training results in greater transference to dynamic performance.”

It’s not even worth attempting to summarize this systematic review, but if you’re interested in seeing what literature is out there regarding “advanced techniques” in resistance training (drop sets, rest-paused sets, etc.), you should check out this article to find all of the relevant studies in one place.

“Muscle fiber hypertrophy of ≤10% induces increases in myonuclear content, although a significantly higher number of myonuclei are observed when muscle hypertrophy is ~22%. Additional analyses showed that age, sex, and muscle fiber type do not influence muscle fiber hypertrophy or myonuclei addition.”