If you train for athletic performance, you should focus on full range of motion. That’s the take-away from a recent study comparing the effects of 15 weeks of training with either partial of full ROM on muscle architecture and mechanical properties.
Untrained males trained their legs using an isokinetic dynamometer. It’s a contraption that works like a leg extension machine, but with a constant movement speed independent of the applied force. The subjects trained one leg using partial range of motion, and the other leg with a full range of motion. Training volume was equalized between the legs by manipulating reps, sets, and muscular time under tension.
The results after 15 weeks showed that only training with full range of motion improved muscle fascicle length. A muscle fascicle is a bundle of muscle fibers. The longer your muscle fascicles, the higher your muscle contraction velocity. Improving fascicle length also improves muscle function and action.
The leg trained with a restricted range of motion didn’t show these improvements. On the other hand, partial ROM increased the physiological cross-sectional area of the trained muscles more.
Most likely, it’s a good idea to base your training on full range of motion movements if you are training for athleticism and overall strength. A full range of motion is critical to improve muscle fascicle length, and since fascicle length is important for rapid and powerful muscle action, this is the most well-rounded approach for physical performance.
If your goal is muscle hypertrophy, it might be a good idea to train with a partial range of motion now and then, as part of your approach. This increases time under tension and could lead to greater muscle growth.
Influence of full range of motion vs. equalized partial range of motion training on muscle architecture and mechanical properties. European Journal of Applied Physiology. September 2018, Volume 118, Issue 9, pp 1969–1983.