Written by Jack Boardman
Partial Range Reps
If you don’t know what a partial rep is, chances are you’ve seen someone performing an arm curl or extension with a range of only a few inches. You’ve probably also wondered if they’re doing something you should know about, whether it’s easier and if it’s more effective.
Can you build more effectively with partial reps than full range reps? As with many elements of weightlifting and the numerous tips and guides out there on the internet, this is a divisive debate, with the majority ruling that, sadly, no, partial reps are not more effective than performing the same exercise with a full range of motion.
A partial rep mimics a full-range motion and therefore allows you to add more weight for that smaller range and therefore strengthen it. Using the example of an arm/ tricep extension using a cable, you may begin the motion from halfway, a 50-75% range, or even smaller. There is a valid reason in each. Further to this, a partial rep is widely considered an effective approach to isolating a specific muscle and, for many, is used when working on muscle failure.
Going into the answer to the above question a bit more, it is not that you can’t build with partial reps, more that it is not essential for mass muscle gains.
Again, going back to the tricep cable extension example, by working at 50-75% range (going from the middle of your usual range to about three-quarters and back) you will feel the brunt of the weight lower down on the back of your arm. Compare this to a 0-50% (normal start to midway extension) and you’ll feel this further up on the back of your arm.
This is an example of how partial reps are not obsolete in building, but not entirely essential. This is because when it comes building serious mass, the answer will always be basic compound lifts that channel as many muscle groups as possible. Partial rep ranges will require fewer muscle fibres and essentially work for smaller muscle groups at a higher capacity.
Gains can be made though. A big advantage of partial reps is that many advanced lifters find they can lift around 10% more weight in the average partial motion lift, compared to full range. This may be utilised to your advantage in several ways.
When performing a partial rep you avoid lockout positions, and may equally experiment with speed and weight so as to build your strength and/ or endurance. By taking advantage of being able to lift more with a partial rep, you could break up the full range of motion into fractions and build your strength in each partial range of movement, therefore contributing to your overall strength when carrying out the full-range motion.
Many people favour partial reps for pumping up and muscle failure at the end of a workout. Whereas ‘pumping up’ your muscles will not necessarily result in mass muscle gain but the impression of it, working to muscle failure has been proven to contribute to muscular hypertrophy. In using partial reps to this end, you could zero in on a specific smaller muscle group in order to build – a good example being the biceps. As with all isolating exercises, the trick here is in the planning, and you’ll need to make sure you do this the day before an adequate rest day when that muscle will not be needed for other exercises.