Myo Reps Explained: How to Build Muscle in Less Time | Legion

Myo reps are a strength training technique designed to make your workouts more efficient by helping you do more “muscle-building” reps in less time.

Instead of doing several traditional sets with long rest periods, Myo-rep sets have you perform one traditional set (referred to as an “activation set”), then multiple short sets with only a few seconds of rest in between.

Fagerli’s stance draws heavily on Henneman’s Size Principle, which explains how your body recruits muscle fibers. Here’s the gist:

• Your muscles don’t activate all fibers at once. They start with smaller, weaker, “slow-twitch fibers” and only call in the larger, more powerful, “fast-twitch fibers” when absolutely necessary.
• These fast-twitch fibers—which also have the most potential for growth—only “switch on” when you either lift heavy weights or become so fatigued that your body has no choice but to use them.
• In traditional training, you use multiple “long” sets to reach the point at which your muscles recruit all available muscle fibers. In comparison, Myo-rep sets get you to this point faster by keeping rest periods extremely short so your fast-twitch fibers stay switched on.

Here’s a graph to illustrate this point:

Myo reps are straightforward once you understand the structure. Here’s how to do them step by step:

• Rest for 5-to-15 seconds. The best way to time this without losing focus is to take 3-to-5 deep breaths.
• Do 3-to-5 more reps.
• Repeat this cycle for up to 5 Myo-rep sets or until your reps drop below 3 reps per Myo-rep set.

Here are a few examples of how your Myo-reps sets might look:

• 20 reps + 5 reps + 5 reps + 5 reps
• 22 reps + 3 reps + 3 reps + 3 reps + 2 reps
• 25 reps + 5 reps + 4 reps + 4 reps + 4 reps + 3 reps

Myo-rep match sets are a variation of Myo-rep sets where you set a “rep target” in your activation set, then use Myo reps to “match” your rep target in all subsequent sets.

Their main benefit is they allow you to reach failure even more times per exercise than regular Myo-rep sets, which may help you build more muscle, provided you can recover from the extra volume.

Follow these steps to perform Myo-rep match sets:

1. Perform an activation set, stopping 1-to-2 reps shy of failure.
2. Note how many reps you completed—this is your rep target for all subsequent sets.
3. Rest as you normally would between traditional sets (typically 2-to-3 minutes).
4. Perform your next set, aiming to match your rep target in one go.
5. If you can’t hit that number, rest 5-to-15 seconds (or 3-to-5 breaths), then do a Myo-rep set of 3-to-5 reps.
6. Continue doing Myo-rep sets until you reach your rep target.
7. Rest for 2-to-3 minutes, then repeat the desired number of sets following the same steps.

To understand how this might look in practice, let’s say you’re using Myo-rep match sets for dumbbell side lateral raises.

In your activation set, you complete 20 reps. This means every subsequent set must also reach 20 reps.

In your next set, you push until you’re 1-to-2 reps shy of failure and manage 15 reps. You’re 5 reps short of your target, so you rest for 5-to-15 seconds (3-to-5 breaths), then do a Myo-rep set of 3-to-5 reps.

In this set, you do 4 reps, taking you to 19 total reps—still 1 rep short of your target. You rest another 5-to-15 seconds, then do 1 rep to match your rep target and finish the set.

You rest 2-to-3 minutes, then repeat the process for all sets of dumbbell side lateral raises in your workout.

Yes, Myo reps can be a highly effective way to build muscle—especially if you’re looking to train more efficiently or increase your training volume.

That said, they aren’t always necessary or ideal for everyone. Some gymgoers find that repeatedly pushing to failure is more uncomfortable and mentally draining than traditional sets, which can make training less enjoyable.

Because they’re so fatiguing, other people struggle to maintain good form during Myo reps, which can be offputting and increase injury risk.

If you’re new to strength training, Myo reps are also unnecessary for muscle growth and may needlessly overcomplicate your routine. Beginners progress just fine using standard sets, so there’s little reason to add complexity that could detract from your training.

To avoid excessive fatigue, use Myo reps for just 1 or 2 isolation exercises per workout and limit yourself to 3-to-5 Myo-rep sets per exercise. Doing more than that won’t necessarily lead to better results and may make it harder to recover.

Borge Fagerli never explicitly defined Myo reps’ meaning, but the most likely explanation is that “Myo” comes from “myofibrillar hypertrophy”—a type of muscle growth that happens when muscle fibers build more contractile proteins.

Since Myo reps aim to increase the reps that drive muscle growth, the name likely reflects their focus on building muscle efficiently.

Technically, Myo reps are a type of rest-pause training, developed and popularized by Borge Fagerli. However, “rest-pause training” is a broad term that refers to any method where you take short breaks to extend a set—whether for muscle growth, strength, or endurance.

What makes Myo reps different from other rest-pause training is they have a specific structure, with an activation set followed by short rest periods and small clusters of reps called “Myo-rep sets.”