Strength training is all about progressive overload – constantly striving to lift more than previously in order to stimulate new muscle growth. One of the keys to to this is breaking through the inevitable plateaus in your weight training. A great strategy to shock your body into new muscle growth comes from only doing a partial repetition, as contradictory as that mean seem.
Partial Repetitions, or “partials” as they are known, focus on a mere 35-45% of the range of motion of a particular exercise, where you can focus on moving more weight than you could had you tried to perform a full range repetition. Partials are a great tool to add to your workout program for one or two weeks every two months or so. The benefit of ‘partials’ is that you move such heavy weight that your body is forced to adapt (grow) to this new stimulus, it also strengthens joints and connective tissues, which prepares your body for heavier weights and more muscle growth when you return to full range repetitions.
I am sure you have noticed that on most exercises you are stronger in different parts of the range of motion than others. As an example with the bench press everyone is much stronger on the last one-third of the movement – the push at the top. We are all much weaker at the bottom part of the bench press, when the bar is closest to our chest. The same applies to the squat as we are much stronger on the top portion of the squat than we are at the bottom. Using a full range of motion limits you in terms of how heavy a weight you can use, as the weak point – the bottom of the movement – determines how much weight you can put on the bar.
Using Partial Repetitions and focusing on the top (strongest) portion of the exercise, you are able to load the bar with weight dramatically heavier than you could doing full range of motion reps. On compound movements you will find that you will surprise yourself with how much weight you can use as you are only covering your strongest portion of the movement. Taking the bench press once again, if you currently bench 200 pounds for full range, you can feel comfortable in trying to use up to 300 pounds (!) when performing partials.
The benefit of performing ultra-heavy partials is that you can push your muscles through limits once thought unattainable. Your connective tissue adapts to become stronger, your muscles grow in response to this new intense stress, and when you go back to performing the mainstay of your workout, full range of motion reps, you will be stronger and able to use more weight but now through a full range of motion. It is also a good idea to use partial reps for a second consecutive week but only focusing on the weakest part of the movement (in bench press and squats this would be the bottom). You will have to use much lighter weights and only move the bar 35-45% of the bottom range of motion but this, in turn, strengthens muscle and recruits fibers in what was your weakest point.
By utilizing Partial Repetitions you can increase the amount of weight you can use because both the strongest and weakest parts each movement are now stronger and capable of handling heavier loads. Heavier weight performed through the full range of motion will recruit more muscle fibers and force muscle growth due to this new shock. Our muscles will only grow when they are given a good reason to do so – partial reps are just the motivation they need.
Start slowly, your muscles and connective tissue need to adjust to this new heavy load
Partials are not to be performed as a complete exercise program, only to be used every now and then to force new growth and break through plateaus – longterm full range of motion is the way to go, this is your bread and butter.
Use and Power Rack or Smith Machine for partials, they provided the support and safety you will need.
Finally, too many people lift too much weight performing partial repetitions but they do so thinking that they are performing full reps. If your bench press does not involve the bar touching your chest (not bouncing off of it) then you are not performing full reps. Same with squats, if your hips do not drop lower than your knees, this is not a full squat. Don’t make Partial reps part of your daily training, train for full range of motion unless specifically using partials strategically.