Pack on Monster Muscle Partial vs. Full Reps
Walk into any gym and head over to the leg press machine and chances are you will see a guy with every plate on the leg press. To the novice lifter, one would think this is an excellent way to build muscle. It makes physiological sense that if you overload a muscle, it’s going to grow. That’s why all those heavyweights are in the gym, to cause muscle damage and spur new muscle growth. It makes sense that using a heavier weight is going to cause more muscle damage and result in more muscle growth. If you notice these lifters that load up the weight on the leg press, many times, they use a partial range of motion instead of using a full range of motion. Partial vs. Full Reps…Does it matter if you use a full range of motion while you are lifting? Is it important for muscle growth? Here are a few studies which may change your mind about using partial reps.
Study # 1: Partial vs. Full Reps Muscle Activity
The earliest studies looked at the muscle activation of full and partial ranges of motion. Not surprisingly, the execution of a full range of the movement elicited the greatest muscle EMG activity.
This means using a full range of the movement is going to activate more muscle fibers than using a partial range of movement. Based on this study, using partial reps is not going to fully activate the muscle like doing a full range of motion. Using a full range of the movement is going to activate more muscle fibers and lead to better muscle growth.
Study # 2: Partial vs. Full Reps Muscle Damage
Let’s get back to the guy who loads up every weight in the gym on the leg press, is he going to stimulate maximal muscle damage? One would think that using more weight is going to cause more muscle damage, but that’s not what researchers found. Researchers examined subjects’ markers of muscle damage after full and partial reps during bicep curls immediately, 24 hours, 48 hours and 72 hours after exercise. The weight lifted in the partial range of motion condition was 40% higher compared to the full range of motion. Despite the 72 hours after exercise, the full range of the movement led to significant higher soreness sensation in the biceps. In conclusion, bicep exercises with full range of motion seems to induce greater muscle damage than partial range of motion exercises, even though a heavier weight was used with partial range of motion. So if you love that feeling of soreness after a workout, use a complete range of motion.
Partial vs. Full Reps for Muscle Growth
A couple of scientists wanted to test if loading up the bar was going to result in greater increases in muscle mass and strength. Forty subjects were placed into one of three groups:
-Full repetition range,
-Partial repetition range, or
Biceps were trained using preacher curls on a machine. The partial rep group restricted their range of motion to half of the movement. The weight used was not equal for both groups, however, as the partial group did not have to fully extend, so the amount of weight they were able to handle for the target reps was higher than the full group could handle.
One would expect the group that used heavier weight would have greater increases in muscle mass, but after ten weeks, the full range of motion group had increased their one-rep max by 25.7% above where they’d started.
The partial repetition group had increased their 1RM only 16% over baseline. When it came to muscle size, again, the full repetition group that used a lighter weight had slightly greater increases in muscle size than the group that did partials.
Using a full range of motion results in greater muscle damage, muscle activity, and muscle mass despite a lighter weight being used. Don’t leg your ego get the best of you in the gym; using a lighter weight and a full range of motion is the best way to train.