In trained individuals, lifting weights through partial ranges of motion or at longer muscle lengths produces the same amount of muscle growth as lifting through full ranges of motion.

We analyzed the available evidence on partial versus full range of motion training in trained individuals, and what we’ve found so far suggests that lifting through partial ranges of motion can produce similar muscle growth as lifting through full ranges. This conclusion is based on 75.0 supporting assertions and no refuting evidence in our current review [1]. The data we’ve examined focuses on people who are already experienced with resistance training, not beginners. In these individuals, training with movements that don’t fully lengthen or shorten the muscle — such as partial squats or lockout-only presses — appears to stimulate muscle growth at a rate comparable to full-range movements. This doesn’t mean partial reps are better, only that they don’t seem to hold back growth when compared to full-range work. It’s important to note that “muscle growth” here refers to increases in muscle size, not strength, endurance, or joint health. We also don’t have data on whether partial reps affect long-term joint function, movement patterns, or injury risk. The evidence we’ve reviewed doesn’t explain why this similarity occurs, only that it appears to happen. Our current analysis doesn’t show that partial range training is superior, nor does it suggest it’s inferior. It simply shows that, in trained people, both approaches lead to similar outcomes in terms of muscle size. If you’re already lifting regularly and want to mix in partial reps — perhaps to target a sticking point or reduce joint stress — the evidence we’ve reviewed doesn’t suggest you’ll lose muscle growth by doing so.