Myo-reps – a time-efficient method for maximum muscle growth
In 2006 I developed the first version of Myo-reps, and I later refined it to the current version in 2008. It has proven to one of the most effective tools I have ever used in both myself and my clients, and I will present the basics of it in this article. Myo-reps is, simplistically speaking, a rest-pause method, and the most famous permutation of it is DC/Doggcrapp training. Most of you probably know how to perform a rest-pause set, and I didn’t just reinvent the wheel here, I refined it building on research on hypertrophy in recent years.
First of all I must give credit where credit is due, to Mathias Wernbom, who presented the most comprehensive meta-review to date on strength and hypertrophy training in 2007 (1), and has been deep into the field of occlusion training the last few years. Matt has provided vast amounts of data to me, hooking both himself and subjects from various populations – a lot of them elite athletes (Toppidrettssenteret, Olympiatoppen) – to EMG machines and sticking huge biopsy needles into muscles (if you ever had a biopsy performed you will know how excruciatingly painful that experience is). Do a search on Wernbom at PubMed and you will see a list of published papers by him. I’m fortunate enough to have access to some unpublished research as well, obviously.
Much credit also goes to Dan Moore (originator of the Max Stimulation method), a brilliant man having what must be a photographic recall of various studies and their results.
And last, but not least, all of my clients over the years who have provided me with valuable feedback and allowed me to fine-tune and evolve Myo-reps principles and templates.
Let’s first look at the primary identified mechanisms of hypertrophy:
- Mechanical deformation: Stretch and contraction under load will initiate a signaling cascade translating into a cellular response, increasing the contractile machinery of the muscle cell. You need to lift weights to grow. Fundamental stuff, indeed.
- Motor unit and muscle fiber recruitment: The research is pretty clear on the fact that you eventually need to recruit most of/all of the motor units and muscle fibers in a muscle to stimulate maximum muscle growth.
- At approx. 80%+ of 1RM (about 5-8RM loads) you are pretty much at 100% fiber recruitment from the very first rep. I generally don’t use Myo-reps for loads heavier than 5RM.
- At lighter loads, you won’t recruit all muscle fibers from the beginning, but as you fatigue you will have to call upon more muscle fibers to complete the set. The last few reps of a set will achieve 100% fiber recruitment, so e.g. a 12RM set has approx. 3-4 “effective” reps at the very end. Not saying that the first reps are ineffective, they are needed to accumulate sufficient fatigue to reach all fibers of the muscle. There has been a lot of research into occlusion-type training where dramatic hypertrophy is observed even with very light loads (20-50% of 1RM) just by tying a blood pressure cuff around an arm or a leg. The main mechanism seems to be an earlier full fiber recruitment effect from the hypoxia (oxygen deprivation) created from occluding the blood flow. Research by some of the most renowned scientists in the field (2) has shown that lifting 30% loads to failure induced more muscle growth than 90% loads to failure, and we’ll have a look at how Myo-reps takes advantage of this mechanism and even improves it further.
- You will also achieve full recruitment transiently by lifting a light load as fast as possible, but only in the turn-around phase from the eccentric to the concentric phase and in the early part of the rep when the weight is still accelerating. By using elastic bands or chains you may increase this acceleration phase by having to push harder vs. slowing down as leverages usually improves at the top of e.g. deadlifts, bench press and squats.
- Metabolic stress, calcium flux and volume: The muscle has to perform a minimum threshold of work with the imposed load and mechanical tension. Reps and the work:rest ratio sets the metabolic state of the muscle. Short duration high-amplitude pulses of calcium into the muscle by high load contractions and rest between sets induced muscle hypertrophy, longer duration low-amplitude pulses such as in cycling or running induces endurance adaptions. Metabolic stress and volume is said to “modulate” the hypertrophic response, i.e. the load is the primary variable, the sets and reps determines the magnitude and duration of the muscle growth you will get out of it. Your volume threshold increases over time, so as you get more advanced not only can you *tolerate* more volume, you will also *need* more volume to stimulate further gains. This also explains why bodybuilders are more muscular than weightlifters or powerlifters, even though the loads used are less, they perform more work in less time with it. Two additional benefits, and one caveat:
- Metabolic stress “sensitizes” the muscle to growth signaling, i.e. you achieve more growth from less work.
- Metabolic stress increases the supply of energy substrates to the muscle, i.e. glycogen stores, blood flow, oxygenation, capillarization, mitochondrial function, and also the cardiovascular component of the heart and lungs which will improve intra-set and intra-workout recovery in the long-term.
- If you overdo it, you increase AMPK – one of the primary energy-sensors of the cell – and this can inhibit protein synthesis and initiate endurance adaptions. This is why extensive interval training (20+ minutes of sprints with short rest, Tabatas with a 2:1 work to rest ratio etc) doesn’t necessarily lead to massive muscle growth – excessive metabolic stress and calcium flux combined with depletion of energy substrates turns on endurance and turns off muscle growth.
- Hormones and amino acids: The usual suspects testosterone, GH/IGF-1, insulin, cortisol, protein. Some more important than others, and the hormones seem to play more of a permissive effect in muscle growth, some studies show rapid hypertrophy in knock-out models where the receptor for various hormones are removed altogether. Getting hung-up on transient elevations from what you eat or how you train is pretty much irrelevant and more of a correlative than a causative effect. Amino acids are pretty much mandatory as they provide building blocks for muscle growth, but the body is very good at recycling them which is why you can grow muscle even under fasting conditions.
A great summary of the above principles can be found in Keith Baar’s meta-review (3).
Two things to note here: 1. Kaatsu (blood flow occlusion by pressure cuffs) increases the EMG signal, and hence fiber recruitment earlier. 2. After the first set and a short rest period, you achieve higher fiber recruitment earlier in the subsequent set. This forms the basis for Myo-reps. (illustration from (4)).
The Myo-reps set from start to finish
Simplistically speaking we basically need to lift a sufficiently heavy load, for a sufficient number of sets and reps, sufficiently often to build muscle at the optimal rate. There are many ways of achieving this, and Myo-reps is simply a very time-efficient and productive tool to have in your repertoire. Don’t get married to one rep range or one method of training if you want maximum results, a planned and strategic variation with both heavy and lighter loads, high and low volume, high and low frequency is needed if you want to maximize results, but that is an extensive topic to cover and I will save it for later articles.
Let’s see how you perform a Myo-rep set from beginning to end. I recommend 2-3 warm-up sets of progressively increasing loads of 8-12 reps prior to the work set both to increase neural drive, to provide additional volume and to let you determine your daily strength level and hence, work set load. (Edit 2016: when you are familiar with Myo-reps, you will be using lighter loads that do not actually require any extensive warm-ups. Sometimes you may just go straight into the Myo-rep set with only a general, dynamic warm-up beforehand.)
- Pick a load you can perform 9-20 reps with (depending on your programming and exercise selection). I will sometimes go even higher, to 25-40 reps. (Edit 2016: I will normally select 30% loads – of 1RM – for beginners, 40% loads for intermediates and more advanced lifters, 50% loads for advanced/elite).
- Go to failure or 1-2 reps short of failure, judged by when rep speed slows noticeably. This is your “activation set” where you achieve full fiber recruitment. Total failure isn’t an absolute requirement, and leaving a rep or two in the tank will allow you to do more total reps, as we shall see soon.
- By keeping constant tension on the muscle, i.e. shorten the ROM by 10% on top (avoid locking out the weight) and 10% in the bottom (resting the weight or overstretching the muscle), you will mimic the occlusion effect and reach higher fiber recruitment faster.
- Now the important part – rerack the weight and rest for (edit 2016: 3-5 deep breaths) – unrack the weight and keep going for up to 3-5 short mini-sets of 3-5 reps (staying close to failure on each mini-set). By keeping the rest period short you will maintain fatigue level, and hence – fiber recruitment at a high rate. All reps of the mini-set are now “effective” reps. I simplify the rest period prescription by counting deep breaths, similar to the DC method, where 3 deep breaths (in+out) is about 6-8 seconds, 5 is 10-15 seconds. You can get away with the higher end (30secs) with heavier loads, at lighter loads you should keep rest periods short (5-15secs) to maintain high fiber recruitment. It is also productive on the Myo-rep series to keep constant tension on the muscle by shortening the ROM. (edit 2016: I rarely use heavy Myo-rep training nowadays, it is far more productive as a metabolic/pump-type stimulus).
- End the Myo-rep set when you lose 1 rep from the initial or 5 mini-sets.
Examples (all correct):
20 +4+4+4+3+3 (stop when you lose a rep from the initial)
22 +3+3+3+3+3+3+3+3+3 (stop at 5 sets of 3 reps)
18 +5+4+3+2 (same as the first one, stop when you lose a rep from the initial)
Let’s illustrate the difference between a “traditional” 3 sets of 20 vs. a Myo-rep set, the asterisk ‘*’ denoting “effective” reps:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15* 16* 17* 18* 19* 20*
1-2min of rest
1 2 3 4 5 6 7 8 9 10 11 12 13 14* 15* 16* 17* 18* (a typical drop off in reps if using a 20RM load)
1-2min of rest
1 2 3 4 5 6 7 8 9 10 11 12* 13* 14* 15* 16*
So you did 54 total reps in about 6 minutes, where 15 reps were “effective” reps (at sufficiently high fiber recruitment).
Now a Myo-rep set:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15* 16* 17* 18* 19* 20* – 15sec rest – 1* 2* 3* 4* 5* – 15sec rest – 1* 2* 3* 4* 5*- 15sec rest – 1* 2* 3* 4* 5*- 15sec rest – 1* 2* 3* 4* 5* – 15sec rest – 1* 2* 3* 4*
Here you did 34 total reps in about 2,5 minutes, where 29 reps were “effective”. The premise here is to *manage* fatigue to get in more work in less time, and you have to balance the reps and rest periods in the Myo-rep set appropriately.
Auto-regulating your way to better results
There are two ways of managing volume here.
First, you can prescribe a total number of reps for an exercise, and I would recommend that you get at least 10 reps after the activation set. An example would be (the ‘+’ denotes 10-20sec of reracking the weight and resting): 12 +3+3+2+2 (or 12 +10). Lighter weights generally need more volume, so: 20 +5+5+5+5+5 (or 20 +25) which would also be a productive Myo-rep set. You generally just keep doing mini-sets of 2-5 reps until you hit the prescribed total rep count.
The second way, and my favorite, is auto-regulation where you let the total volume (number of reps) take care of itself based on how you feel that day – your individual recovery level. Example protocols, if I prescribe reps for the activation set (sometimes I test or estimate 1RM, then prescribe a load of 30-50% of that for the activation set:
The first part (e.g. 12-15) denotes reps in the activation set, the number after the + is how many reps you will do in the Myo-reps mini-series. So 12-15 +3-5x may look like this:
200lbs x 14 +3+3+3+3+2 – you weren’t able to do the third rep of the last set so you stop there
Here’s how auto-regulation works:
Let’s say you had a good night’s sleep, ate well, had a day off from work, and generally feel great and well recovered. The 12-15 +3-5x protocol would most likely turn out like this:
200lbs x 15 +5+5+5+5+5
Now, let’s say you had a couple of drinks too many at your brother’s bachelor party last night, your girlfriend broke up with you because you fondled the stripper, the neighbour’s cat kept you awake, and you’ve been dieting for 3 months. The same protocol would most likely deteriorate to this:
200lbs x 11 +3+2
Doing less work when your recovery and adaptive reserves are compromised makes logical and practical sense, and you will most likely come back stronger the next time (provided you stay sober, stop dieting, kiss and make up with your girlfriend – or the stripper if she was really hot) vs. struggling to do the same amount of work you had planned to, or even more by adding sets and dropsets to punish yourself for being such a failure as a human being. Stimulate, don’t annihilate.
You will also note that various muscle groups and exercises have different recovery rates and volume tolerances, so if you consistently get something like 11 +3+2 I recommend longer rests (6-7 deep breaths), if you consistently get 15 +5+5+5+5+5 and feel like you could have kept going forever, use shorter rests (1-2 deep breaths).
Note that you can also do more reps in the Myo-rep series by doing short ROM partial reps.
I won’t go much into detail on exercise selection and template structure, there are many ways of programming your training strategy and I would rather save that for a later article. I will just briefly mention that I usually do at least 2 exercises for major muscle groups, and more if it is a priority muscle group (or another Myo-rep set of the same exercise). Dumbbell presses are less suitable for Myo-reps, as it requires a lot of energy to get them into position and stabilize them. Having only a few seconds of rest makes you run out of breath before you get the load to do sufficient work on the muscles. I’m also careful with Myo-reps on squats, deadlifts, and even bent rows as the accumulating fatigue, in the lower back in particular, may compromise technique and increase injury potential.
As you can see, a Myo-rep set takes advantage of the primary mechanisms of muscle growth – mechanical load, increasing fiber recruitment and maintaining it at a high level to get more “effective” reps, increasing the muscle sensitivity to the growth stimulus via metabolic stress, modulated by the volume effect (total sets and reps) and doing more work in less time.
With Myo-reps you can get in and out of the gym in 30 minutes if you are short on time, you can provide a different stimulus to a muscle group from the “traditional” way of structuring sets and reps, and it can even serve as a deload following a high-volume phase. Myo-reps is a great tool to have in your toolbox in the quest for a massive and strong physique, feel free to play around with it and let me know if you have any questions or comments. Hate mail due to severe soreness is also more than welcome…
Borge A. Fagerli
- Wernbom M, Augustsson J, Thomeé R., The influence of frequency, intensity, volume and mode of strength training on whole muscle cross-sectional area in humans., Sports Med. 2007;37(3):225-64.
- Burd NA, West DW, Staples AW, Atherton PJ, Baker JM, Moore DR, Holwerda AM, Parise G, Rennie MJ, Baker SK, Phillips SM., Low-load high volume resistance exercise stimulates muscle protein synthesis more than high-load low volume resistance exercise in young men., PLoS One. 2010 Aug 9;5(8):e12033. – PMID: 20711498
- Baar K., The signaling underlying FITness., Appl Physiol Nutr Metab. 2009 Jun;34(3):411-9.
- Yasuda T, Fujita S, Ogasawara R, Sato Y, Abe T., Effects of low-intensity bench press training with restricted arm muscle blood flow on chest muscle hypertrophy: a pilot study., Clin Physiol Funct Imaging. 2010 Sep;30(5):338-43. Epub 2010 Jul 4.