Photo: Tima Miroshnichenko

100. It’s crazy, right? It’s the length of a football field in yards. It’s a century. It’s enough miles per hour to earn a painful fine. In those contexts, it’s big. But in regards to reps-per-set, it’s huge. Six-time Mr. Olympia Dorian Yates didn’t do 100 working reps in an entire workout! You may not have ever considering cranking out a set of set of 100—until now. The training style known as hundreds targets slow-twitch muscle fibers and fast-twitch fibers too, and it enhances blood flow to your muscles. In other words, it’s a unique and effective means of boosting growth. And there’s nothing crazy about that.


Rory Leidelmeyer, one of the best bodybuilders to never turn pro, used a hundreds program for extended periods. Another top 1980s amateur who barely missed a pro card, Tom Touchstone, followed Leidelmeyer’s lead, as did Diana Dennis, who finished third in the 1985 Ms. Olympia. And Moe El Moussawi, who finished ninth in the 2008 Mr. Olympia, performed high-rep and high-volume training for years, including many sets in the 50-100 range.

100 rep workout
Rory Leidelmeyer in early ’80s form.


Okay, so some famous and semi-famous bodybuilders repped out marathon sets. But how do such high-rep sets affect your muscles?

Let’s turn to our friend, exercise scientist Dr. Jim Stoppani, PhD. “With hundreds training you will hit the slow-twitch muscle fibers during the first 60 reps or so. After that, your muscles will have to call on the fast-twitch muscle fibers to help out the fatigued slow-twitch fibers,” Stoppani explains. “Doing this many repetitions causes biochemical changes in the muscle, which aid in muscle growth. It also leads to greater growth of blood vessels that feed the muscle fibers to enhance the delivery of blood, oxygen, nutrients, and hormones to the muscle cells. This environment increases the growth potential of the muscle fibers.”

The key is to not just choose a weight that you can rep out endlessly with little effort. Instead, select a weight where you reach failure around 60-70 reps. (This should be approximately 1/3 the weight you would use for a 10-rep max.) Then pause as needed to eke out the remaining reps until you reach 100. All of those final reps will be at near-failure. In this way, you fatigue both the slow-twitch fibers (in the first 60-70 reps) and the fast-twitch fibers (in the final 30-40 reps).

Hundreds is never an excuse for light work with a light weight. Instead, it is an intense method of exhausting muscles with long sets.


There are three ways to join the “Century Club.”

You can do an entire program consisting of only three or four 100-rep sets per bodypart. Stick to this for periods of two to four weeks, and followed it with at least 10 weeks of a traditional workout regimen. This is a full-body growth turbo-charger. Your strength may be a little depressed when you return to moderate reps, but it should bounce back within a couple weeks.

Alternately, you can work hundreds into your usual routine as a shock treatment. Do an occasional century set session for a lagging bodypart, or rotate such workouts so that all bodyparts get the treatment from time to time. Not only can this jump-start new growth, but it can also recharge your training in general, especially when you have nagging injuries.

Hundreds can be a time-saver and joint-saver. Don’t have time for your usual workout, or your joints are still reeling from your last one with low reps? Do all the same exercises as usual, but do only one set per exercise for 100 reps. Such a routine will be faster, and it’ll also allow you to train around injuries.

100 rep workout
Barbell curls are a good exercise for hundreds. / Photo: Mario Valenzuela


✷ Select three to four exercises per bodypart. Do only one set of 100 reps per exercise. Warmups are unnecessary.

✷ Use a weight that is approximately 1/3 of your 10-rep max. So, if you normally max out at 225 for 10, use 75.

✷ Ideally, you want to reach failure at between 60-70 reps. Then pause and continue. Pause as many times as necessary to get to 100 strict reps.

✷ Pause for as many seconds as you have remaining. So, if you get 64 reps, rest for 36 seconds. If you then get to 89, rest for 11 more seconds.


✷ You can estimate the time of your rest periods, but if the gym has a clock with a second hand or you keep a counter going on your smartphone, that will make it easy to be accurate.

✷ Set down or re-rack the weight during lengthy pauses.

✷ When you can get more than 70 reps without pausing, move up to a heavier weight.

✷ Choose bilateral exercises, so you don’t need to do 100 reps for each side separately.


Lying Triceps Extension  —  1 set x 100 reps

Smith Machine Close-grip Bench Press  — 1 set x 100 reps 

Pushdown  — 1 set x 100 reps

Barbell Curl  — 1 set x 100 reps

Seated Dumbbell Curl —  1 set x 100 reps

Machine Curl  — 1 set x 100 reps