Experiments With Rest-Pause High Intensity Training

Background

For those unfamiliar with the term, rest-pause is a method of resistance training where a brief pause is taken between repetitions. Some variations involve a pause between every repetition of a set, some involve pausing between reps or groups of reps to enable the performance of additional repetitions after muscular failure has been reached. The rest-pause between reps is typically between 5 and 15 seconds, and some variations start lower and increase as the set becomes progressively harder.

Rest pause is not a new method of training, or even a relatively recent development. Peary Rader wrote about rest pause training in 1946 in one of his Iron Man training courses, The Rader Master Bodybuilding and Weight Gaining System, and Bob Hoffman wrote about a method of rest pause he called Muscle Contraction with Measured Movement in 1962 in his Functional Isometric Contraction – Advanced Course. There have been numerous variations since then, some of the most popular being the 20 rep breathing squats popularized by Randall Strossen in his book Super Squats, Mike Mentzer’s version from High Intensity Training the Mike Mentzer Way, and Dante Trudell’s “Dogg Crapp” training method.

Over a period of several weeks during the summer of 2006 Jon Kilcoyne and I used Mike Mentzer’s version of rest-pause training in our workouts. This involved performing two repetitions using close to one-rep maximum weights with a 10 second pause between reps, followed by two or three more forced reps with the same or a slightly reduced weight. Although this produced noticeable size increases we discontinued after a few weeks since assisting with the forced reps was becoming almost as draining as the sets themselves due to the rapid increases in weight.

We resumed rest-pause training in the fall using a more traditional method after reading Dan Moore’s articles on his Max Stim protocol, which make a strong case for rest-pause for hypertrophy. Rather than the near one rep max weights and 10 second pauses we were using with Mentzer’s rest-pause, we started with our normal weights and a 5 second pause, which initially resulted in a doubling of our rep counts. Over a period of several workouts we increased the weights until we were back down in the 5 to 8 repetition range, which we had both found worked well for us. Within a few weeks my one rep max on the chest press increased by nearly thirty pounds, and our weights had increased significantly on every exercise.

We started using this version of rest-pause with several clients, all with good results. The only downside was most of the Nautilus Nitro equipment we were using did not provide an adequate amount of resistance – Jon and I and most of the male clients using rest pause quickly maxed out several of the machines. This has been an even bigger problem with MedX equipment, which sacrifices resistance for low inertia by limiting the stroke of the weight stacks to under a foot. My preference of machines for rest pause would be first and second generation Nautilus equipment, which had adequately heavy weight stacks, although free weights and well-designed plate-loaded machines would probably be the best choice since they will accommodate even the strongest trainees.

Twin Experiment with Rest Pause

In November of 2006 I started an experiment with a pair of identical twins to compare the effects of rest pause training on strength and muscle mass. Unfortunately, the twins were poor subjects for an experiment on muscular hypertrophy, being small-framed teenage girls and posessing what appeared to be very poor potential for muscular size. Additionally, it was apparent they did not follow my instructions to increase their calorie and protein intake, as there was no significant increase in bodyweight over an 11 week period. I didn’t exactly have identical twins knocking down the doors to participate in training experiments though, so I figured they’d have to do.

On November 13, 2006, I tested both twins’ one rep maximums on the calf raise, seated leg curl, leg press, row, chest press, pulldown, overhead press, back extension, and abdominal machines. Two days later I tested each twin for repetition maximums with 75% of their 1RM. While their reps for the upper body exercises were only a little on the high side, their reps for the leg exercises were absurdly high for 75% of 1RM, which probably had a bit to do with both being long distance runners. Interestingly, both performed very few reps with 75% of their 1RM on the back extension machine.

Both twins performed the same exercises, in the same order, using a repetition range of 8 to 12, a 3 second lifting and 3 second lowering cadence, and rested around 60 seconds between exercises. The only difference was one twin set down the weight and rested for 5 seconds between each repetition. Each twin worked out 16 times over a period of 11 weeks, starting November 20, 2006 and ending February 2, 2007. They were tested again for 1RM on February 6, and for their repetition maximum with 75% of their November 13 1RMs two days later on February 8. The muscular endurance test with 75% of the original 1RM was not retested on calf raise since I stopped both twins when they reached 40 repetitions during the initial test.

Kara: Rest-Pause (8-12 reps, 3/3 cadence, 5 second rest-pause)

Strength (1RM) Average Increase = 30.3%

Endurance (RM with 75% of Initial 1RM) Average Increase = 112%

Kelsey: Traditional Reps (8-12 reps, 3/3 cadence, No rest-pause)

Strength (1RM) Average Increase = 26.3%

Endurance (RM with 75% of Initial 1RM) Average Increase = 156%

Both twins increased their muscular strength and endurance significantly, but much of this can probably be attributed to learning effect since neither gained a significant amount of body weight. While the twin who performed rest pause had a higher increase in 1RM, the twin who performed regular repetitions had a much greater increase in muscular endurance.

Joseph Ross – 8.5 Pounds in Three Weeks

Unlike the twins in the experiment, Joe Ross had above average potential for muscular size gains, and followed my instructions to increase his calorie and protein intake. Joe also performed fewer exercises per workout, and alternated between two different workouts consisting of a few compound exercises each plus direct exercises for the upper arms and forearms. Over a period of three weeks during which he performed six workouts Joe increased his bodyweight from 165 to 173.5 pounds, while maintaining a very low level of body fat. I do not believe Joe’s results are typical, and would be highly skeptical if I did not weigh him and perform the skinfold measurements myself. I believe he could probably gain another 20 pounds of muscle if he continues to train and eat properly.

Recommendations for Rest-Pause Training

Since then, I have been using rest-pause regularly in my own workouts and with several of my personal training and phone clients. After a bit of experimentation, I’ve developed the following guidelines, which have been working pretty well so far.

Rest-Pause Duration: 5 seconds

I’ve been using a rest-pause duration of approximately 5 seconds. The weight is set down completely, unloading the muscles, and two deep breaths are taken: inhale on the one count, exhale on the two, inhale on the three, exhale on the four, then inhale on the five while getting set to begin the next rep. Shorter pauses don’t seem to allow as much of a weight increase, and pauses that are longer than 10 seconds end up taking a bit longer but don’t seem much more effective.

Repetition Range: 5-8

Most clients were able to almost double their repetitions with their normal set weight when performing the 5-second rest-pause between reps, and were able to use significantly more weight for their normal rep ranges. However, since systemic fatigue seemed to become more of a limiting factor when sets went on too long I reduced the upper rep number for everyone to 8 to keep the total set time under 90 seconds. I set the lower rep number at 5 to maintain a minimal cumulative time under tension of around 30 seconds for adequate motor unit recruitment and stimulation.

Some people may do better with slightly lower ranges similar to what Mentzer recommends, some will do better with higher reps, but this has worked well for everyone I have worked with so far.

Weight

When switching from normal, continuous sets to rest-pause I recommend increasing the weight by about 5-10% each workout until you are only able to perform 5 to 8 reps. Bigger weight increases if you normally use a higher repetition range, smaller if you normally use a lower repetition range.

Exercises

Some exercises are better-than others for rest pause training. I recommend using exercises that allow you to set the weight down completely between repetitions. A power rack makes it possible to do this with a variety of barbell exercises. A bench or chair can be placed under a chinning bar for performing rest-pause chin-ups or pull-ups. Most well-designed machines work well for rest-pause, however many newer selectorized machines have weight stacks that are too small for stronger trainees. This is not a problem with plate-loaded machines.

Safety

Due to the much heavier weights that can be handled with rest-pause training, it is absolutely essential that all safety precautions are taken. I highly recommend a power rack for all barbell pressing exercises. If you’re lifting a bar over yourself, you should have the safety pins set at the right height to set the bar on during the rest-pauses and to prevent it from coming down on you if dropped. Inspect equipment before use to make sure there are no loose bolts, frayed cables or belts, or broken welds – I’ve seen all of these on equipment in big-name commercial gyms that were left unfixed for months. Don’t assume any equipment you use is in safe working condition – check it yourself.

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