Partial Credit

When not finishing what you start is a good thing — the ins and outs of the partial reps technique.

A motivational speaker who encourages you to only go part of the way? Not gonna be landing many prime speaking engagements on the corporate convention circuit, that’s for certain.

Incline Barbell Press

But change careers to become a personal trainer, and he could just be onto something.

The “partial rep” intensity technique is exactly what it sounds like: Instead of taking a repetition through its full range of motion —or ROM for short — you stop short, anywhere from three-fourths of the way to a nearly imperceptible “pulse” of a motion.

The key is knowing when to use it, and understanding when you’re cheating yourself out of the complete value of the exercise at hand.

First, when NOT to use it: When you’re lifting too much weight, and in an effort to get a certain number of reps, you shorten your ROM. Think of guys who load up the plates and then lower themselves only a few inches during squats, or those dudes who don’t touch the bar to their chest during bench presses. Those inflated totals may feed your ego, but they don’t maximally challenge the intended muscles.

So when is it okay to cut a repetition short? There are four potential scenarios:

  1. When you’ve reached momentary muscular failure. This is the most common way to employ partials — you rep until you can’t complete a repetition through a full ROM, and then, instead of quitting, you continue by doing as much of the rep as possible. You may initially get three-quarter reps, then one-half reps, and finally you’re just moving the weight an inch or two. This is an effective way to end a workout, burning out every last muscle fiber.
  2. To work through a sticking point.Say you can’t finish the top of an incline press when you’re working up to your max or near max, and you’ve been stuck there for a few weeks. To help bridge the gap and get your muscles accustomed to the new load, you can either set up in a power rack or a Smith machine, putting the pins or safeties at a point where you’re only pressing through that problematic portion of the ROM. Do 3–5 sets after you’ve done your full ROM sets, and that sticking point should soon evaporate.
  3. To acclimatize to a new personal best weight. Along the lines of No. 2, sometimes a sticking point can be overcome through trying a new PB in small doses. If you’re stuck at a certain weight and can’t do reps with the next higher load — we’re talking five or 10 pounds heavier — you can give your muscles a taste of that higher weight through some end-of-workout quarter reps. It’s not advisable all the time, since you shouldn’t be overreaching excessively when working with your max and near-max poundage, but it can be effective when other means are not leading to results.
  4. As part of a set that incorporates both complete and partial-range repetitions. It’s a bit fancy-pants, but for a change of pace, you can mix full ROM and partials in the same set. Take lying leg curls, for instance — during a set, you alternate full to-the-ass reps with half ROM reps, stimulating the hamstrings in a slightly different way.