There’s a simple way make any exercise more difficult: Add a quarter rep between the first and second parts of a normal rep. Think this sounds easy? Give it a try, and your opinion will quickly change.

The technique is referred to as a myotatic rep. “Myotatic” is another term for the stretch reflex that occurs within a muscle. As a muscle lengthens, the nervous system automatically tells the muscle to contract, which protects it from lengthening beyond its limit and tearing.

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Strength exercises take full advantage of the stretch reflex—that is, unless you pause mid-rep. When a muscle lengthens as you lower into a rep, it is ten able to provide a rebound-like effect for the second portion of the rep, similar to when you stretch and release a rubber band.

To see this in action, try doing a Pull-Up without fully straightening your arms. Now do another one with your arms straight in a dead hang. The dead hang is significantly more difficult because the stretch reflex is turned off.

With myotatic reps, you specifically target the stretch reflex by moving up a quarter of the way from the bottom position of the rep, then quickly lowering again to the bottom position and exploding up. Simple as that.

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According to Scot Prohaska, a nationally recognized sports performance consultant, performing it rapidly like this builds explosive power by teaching your muscles to quickly explode from the lengthened position.

Prohaska particularly likes using myotatic reps to build muscle (technically referred to as hypertrophy). He says, “There are three keys to focus on when trying to create hypertrophy: Create muscular tension, create muscular damage and create muscular fatigue. Myotatics accomplish all three.

You can still lift fairly heavy weight at around 75 percent of your max. However, the quarter rep is absolutely brutal. It quickly fatigues your muscles, causes a serious burn and increases the amount of time your muscles have to work. The result? Bigger and stronger muscles.

Just make sure the quarter rep is a true quarter rep. Many athletes have a bad habit of failing to lower far enough into the rep and not going high enough for the quarter rep.

But don’t go to the gym and rip out myotatic reps on every exercise. Do no more than one or two myotatic exercises every week, and make sure they’re in different workouts. If you choose to do myotatic reps on heavy, multi-joint lifts such as Squats, opt for around 4-5 sets of 5 reps. For isolation exercises using moderately light weight, do 3-4 sets of up to 10 reps for a serious burn.

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You can use this technique with almost any exercise, but here are four movements where myotatic reps work particularly well.

Myotatic Squats

This is a great way to strengthen the VMO muscle, which is the large part of the quad on the inside of your thigh. A strong VMO helps to keep your knee stable and reduces the risk of ACL injuries.

Myotatic Bench Press

Builds chest strength and size and helps with your transition out of the bottom portion of the bench.

Myotatic Chin-Ups/Pull-Ups

Adding a quarter rep kills your momentum and forces you to control the top of the Chin-Up, which makes every rep more difficult and adds a significant challenge to your lats.

Myotatic Curls

Want a serious bicep pump? A simple Myotatic Curl is your answer.