PARTIAL REPS CAN RESULT IN SIMILAR GAINS IN MUSCLE AS FULL RANGE EXERCISES [IF DONE CORRECTLY]

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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

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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)

HALF REPS PERFORMED ECCENTRICALLY CAN RESULT IN SIMILAR GAINS IN MUSCLE SIZE AS A FULL RANGE OF MOTION

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 REP AND HYPERTROPHY

The stretch is where all the muscle growth occurs, so doing a bench press in which the barbell touches the chest and is performed with half-reps is more effective (i.e., training at longer or stretched muscle lengths) than bringing the bar down and not touching the chest. The researchers found that training at long muscle lengths or a stretched muscle is more important than a full range of motion.

The study found that a full range of motion resulted in more muscle growth than a partial range of motion only when a partial range of motion was performed with short muscle lengths. When a full range of motion was compared to a partial range of motion at long or stretched muscle, partials with a stretched muscle or long muscle lengths resulted in greater muscle growth than a full range of motion.

NOT ALL EXERCISES ARE THE SAME WITH PARTIAL REPS

The study also observed that not all exercises produce the same muscle growth, even when training at extended muscle lengths. For instance, the seated leg curl led to more muscle growth than the lying leg curl, even though both exercises were performed with a full range of motion. The researchers believe this is because the seated leg curl induces greater hip flexion, which in turn promotes more significant growth in the hamstrings. (5)

The same research team discovered that the overhead triceps extension yielded more muscle growth than the standing triceps extension, even though both exercises utilized a full range of motion.” (6) From their findings, the researchers inferred that training muscles at longer lengths or in a stretched position is more beneficial for muscle growth. However, it’s crucial to note that overstretching a muscle beyond its natural range of motion doesn’t appear to enhance muscle growth. In other words, don’t overextend a muscle thinking it will lead to more significant growth.

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PARTIAL REP RECOMMENDATIONS

The author recommended the following for optimal strength and muscle growth responses for full and partial reps:

A.)  Beginners should perform a full range of motion

B.)   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.

C.)   For muscle growth, training with longer or stretched muscle lengths is preferable. Try experimenting with stretching the muscle and holding it in an isometric position to maximize muscle growth.

References

 

1.         Bloomquist K, Langberg H, Karlsen S, Madsgaard S, Boesen M, Raastad T. Effect of range of motion in heavy load squatting on muscle and tendon adaptations. Eur J Appl Physiol. 2013;113(8):2133-42.

2.         Kubo K, Ikebukuro T, Yata H. Effects of squat training with different depths on lower limb muscle volumes. Eur J Appl Physiol. 2019;119(9):1933-42.

3.         Bazyler CD, Sato K, Wassinger CA, Lamont HS, Stone MH. The efficacy of incorporating partial squats in maximal strength training. J Strength Cond Res. 2014;28(11):3024-32.

4.         Bhasin S, Storer TW, Berman N, Callegari C, Clevenger B, Phillips J, et al. The Effects of Supraphysiologic Doses of Testosterone on Muscle Size and Strength in Normal Men. New England Journal of Medicine. 1996;335(1):1-7.

5.         Maeo S, Huang M, Wu Y, Sakurai H, Kusagawa Y, Sugiyama T, et al. Greater Hamstrings Muscle Hypertrophy but Similar Damage Protection after Training at Long versus Short Muscle Lengths. Med Sci Sports Exerc. 2021;53(4):825-37.

6.         Maeo S, Wu Y, Huang M, Sakurai H, Kusagawa Y, Sugiyama T, et al. Triceps brachii hypertrophy is substantially greater after elbow extension training performed in the overhead versus neutral arm position. Eur J Sport Sci. 2022:1-26.

7. Wolf, M., Nuckols, G., Longer And Stronger: How Range Of Motion And Muscle Lengths Affect Muscle Growth And Strength Gains. https://www.strongerbyscience.com/rom/

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