The researchers found that for muscle growth, training with partials in a stretched muscle or an eccentric contraction resulted in similar muscle growth as a full range of motion. The limiting factor of previous research was that partial reps completely neglected the eccentric portion.
PARTIAL REPS CAN RESULT IN SIMILAR GAINS IN MUSCLE AS FULL RANGE EXERCISES SUMMARY
- Advanced athletes looking to maximize strength should use a combination of full and partial reps, with most of their training with a full range of motion.
- Training at long muscle lengths or a stretched muscle is more important than a full range of motion
WHAT IS RANGE OF MOTION
Range of motion (ROM) means how far and in what direction you can move a joint or muscle. A full range of motion refers to the act of moving a joint as far as anatomically possible during a given exercise. Exercising thru a full range of motion is often advocated for optimal muscle growth. A full range of motion has been shown to result in superior strength and muscle mass increases compared to a partial range of motion.
PARTIAL SQUATS RESULT IN LESS MUSCLE GROWTH STUDY
The classic study had subjects perform a partial squat, and the other group performed a full squat. The partial squat group performed squats from 0 to 60 degrees of knee flexion, while the deep squat group performed squats from 0 to 120 degrees of knee flexion for 12 weeks. At the end of the study, the full squat group had greater muscle growth for all six regions of the thigh, whereas the partial squat only increased in two regions of the thigh.(1)
A similar study found that a partial squat performed at a 90-degree angle resulted in similar muscle growth of the quadriceps, but the full squat resulted in greater muscle growth of the glutes and adductors.(2) These studies suggest partial squats emphasize the quads, but they failed to increase the growth of the glutes and adductors. A person looking to maximize muscle growth would assume that a full range of motion is necessary for muscle growth. Still, new research suggests that it depends on whether the muscle lengths are stretched in a partial range of motion. An article here has some new research on muscle lengths being performed at longer lengths that can cause similar muscle growth to a full range of motion.
WHY IS RANGE OF MOTION IS IMPORTANT
An excellent review of the literature was written on Stronger by Science that analyzed 23 studies comparing full vs. partial range of motion performed at different ranges of motion (i.e., muscle lengths with short vs. stretched muscle partials).(7) The researchers found that a full range of motion was better for overall muscle growth, but the results were trivial. The researchers found that the strength athletes, it’s better to train with a full range of motion as partial ranges of motion result in athletes getting stronger in a partial range of motion; conversely, a full range of motion allows for strength gains in a full range of motion.
The authors suggest that combining full and partial ranges of motion may be beneficial for peak strength gains. For example, a study found that a combination of full and partial squats resulted in better strength gains than just performing a full range of motion. (3) Another study found that combining full deadlifts with partial deadlifts in a power rack resulted in superior strength gains than a group that just performed regular deadlifts. (4)