Do Hi-Rep Sets Work?

Put whatever dogmatic opinions about high-rep sets you have aside for a minute. While eight to 12 reps is touted as the definitive formula for size and strength, getting extreme with your reps can also reap huge dividends in the form of gains. Think performing 100 reps of curls with an unloaded barbell is wimpy? Try it and let us know how you feel afterward. This intense method can help you bring up lagging body parts, be used as a finisher, or even be completed as an entire program.

What It Is

A single set performed for 100 reps, using a rest-pause technique only when necessary. The weight should be drastically lighter than what you’re used to lifting, but, trust us, you’ll be feeling it halfway through.

Why It Works

Performing 100 reps in a single set targets your slow-twitch muscle fibers more effectively than other techniques. This method also flushes more blood to the muscle than a standard set and rep scheme, which means more nutrients will be delivered to the isolated area. You won’t gain much strength on this program, nor should it be followed for a prolonged period of time, but if it’s used strategically you can induce substantial amounts of hypertrophy.

When to Use It

You can construct a whole program around this method or feel free to use it as a way to finish off your muscles. If you’re lacking in a certain area, 100-rep sets are a great way to bring that muscle up to par as well.

100 Rep Basics

Select three to four exercises per body part. Perform just one set of 100 reps per exercise. Warmup sets are unnecessary, but a dynamic warmup before any training session is always advised.
Use a weight that is approximately one-third of your 10-rep max. So if you normally max out at 225 for 10, use 75.
Ideally, you want to reach failure between 60 and 70 reps. Then pause and continue. Pause as many times as necessary to get to 100 full reps.

Rest-pause for many seconds as you have reps remaining: If you get to 64 reps, rest for 36 seconds; if you then get to 89, rest for 11 more.

100 Rep Tip Sheet

Either count out the seconds of rest periods, use the second hand of a clock or watch, or have a partner time them with a smartphone.
Set down or rerack the weight during lengthy pauses. When you can get more than 70 reps without pausing, move up to a heavier weight
Choose 3 bilateral exercises so you don’t need to do 100 reps for each side separately.

source https://www.makingthebest.com/2017/03/26/do-hi-rep-sets-work/