Translated and compiled by Janar Rückenberg
The conventional, traditional thinking among most bodybuilders boils down, broadly speaking, to the following:
Strength: 1-5 reps per set
Muscle mass: 6-12 reps per set
Muscle mass for slow-twitch fibers: 12-20 (or even more) reps per set, for example for the thighs and calves. Some, however, consider the 10-20 rep range to be the range for definition and detail instead.
Translator’s note: Honestly, I don’t quite understand what “definition training” is supposed to be as a separate thing. Is there really a separate kind of strength training for the contest-prep period and another for the mass-building period? In reality, the nature of strength training, as far as rep count goes, shouldn’t change before a competition at all. Contrary to popular belief, training weights must be maintained as much as possible during contest prep, as this helps us hold on to muscle. It’s true that in the pre-contest period the number of exercises per muscle group goes up and isolation exercises are added, but there is definitely no need to stretch the rep count in the sets any longer.
It’s true that there are bodybuilders who, before competitions, partly (a few workouts now and then, or for certain exercises) extend their sets to 10-15 reps, but in my understanding this also comes from the fact that the aim is rather to deepen the energy deficit with this approach and deplete the muscles of carbohydrates. This makes it possible to shorten the aerobic session after strength training or skip it altogether. But in general, even before competitions you should try to keep the weights up.
Coming back to the topic, there are always problems with these general beliefs and ways of thinking.
MUSCLES DON’T COUNT REPS. A GREAT MANY AUTHORS HAVE SAID THAT TO TRAIN FOR MUSCLE MASS AND HYPERTROPHY, A SET SHOULD LAST 30-70 SECONDS. SO IF TWO INDIVIDUALS ARE TRAINING FOR MUSCLE MASS, THE REP COUNT IN A SET IS ACTUALLY DICTATED BY THE DURATION OF ONE REP. SO THE REP COUNT CAN BE QUITE DIFFERENT FOR SOMEONE WHOSE REP TAKES 10 SECONDS AND FOR SOMEONE WHOSE REP TAKES 2-3 SECONDS.
Misapplying and misunderstanding reps
A good example of reps and sets being misinterpreted is Mike Mentzer’s recommendations. In his training programs and articles, Mentzer always recommended a rep range of 6-10 reps per set. This led people to believe that Heavy Duty means lifting heavy weights. In reality, things were not like that at all. The rep range Mike recommended was indeed 6-10, but he specified 10 seconds for each rep.
So if we do 6 reps per set, the set lasts 60 seconds. That is 60 seconds with the muscles under tension/load. Most bodybuilders do their 6 reps in 12-18 seconds.
That is a huge difference: it dictates which weight we use, or even make sense to use. The duration of the set also determines the results.
This is actually a very important component and aspect of training, one that has somehow been forgotten or overlooked over the years.
When the general recommendations for mass-building workouts for the so-called average trainee emerged and were “invented” through studies and experiments, what came out of it was the so-called mass rep range of 8-12 reps per set, WHILE ASSUMING THAT A REP TAKES SIX SECONDS, WITH 2 SECONDS SPENT ON THE CONCENTRIC (LIFTING THE WEIGHT) PHASE AND 4 SECONDS ON THE NEGATIVE, OR ECCENTRIC (LOWERING THE WEIGHT), PHASE.
As said, a rep should take 6 seconds, so with 8-12 reps per set, the set should last 48-72 seconds. This is very important and essential to keep in mind when it comes to building muscle mass (hypertrophy) and the physiology of the exercise.
Muscles don’t count reps!
And that really is how it is: muscles don’t count reps, and the only thing they “understand” is the time they spend under load (TUT, TIME UNDER TENSION, OR TUL, TIME UNDER LOAD). These last two expressions are essentially synonyms.
To add muscle mass through strength training, a muscle has to be under a certain load, and the tension that results from the load (the weight) has to last a certain amount of time in order to trigger certain adaptive changes. An adequate load over a certain period of time is what triggers the chemical reactions in the muscle that underlie adaptation. One outcome of this much-discussed adaptation is muscle hypertrophy.
With adequate recovery and enough rest before the next workout, the muscles’ adaptation is realized as hypertrophy: they gradually grow bigger and stronger (nutrition, of course, matters too).
The amount of tension (load) on the muscle and the length of time the muscle is under that tension are inversely proportional. This should already be familiar to the reader. Once again: to grow muscles, to add muscle, you have to train harder (more intensely), not spend more time in the gym.
The intensity on the muscles, the tension on the muscles, has to be such that the body doesn’t start using its aerobic mechanisms to do the work (the resistance shouldn’t be too low). At the same time, the resistance has to be high enough that the tension on the muscles lasts long enough to trigger positive anaerobic reactions in the muscles.
This is where the rep count of 8-12 comes from. The average trainee actually doesn’t know that this rep count (8-12) was “born” out of the favorable length of time that muscles should be under load to produce hypertrophy. Not the other way around!
Time under tension, i.e. the most favorable time for producing hypertrophy, 48-72 seconds, was in fact the basis for developing the scheme, the 8-12 rep range.
Next time you go to the gym, watch how fast most trainees “get their reps over with”!
In the gym…
You’ll discover two things. First, nobody keeps track of the time the muscle is under tension, in other words the speed at which a repetition is performed. For most lifters, a rep takes one second down and one second up.
In a set of 8-12 reps, the working muscle may be under maximum tension for only 16-36 seconds, and no more. That is far below any standard, and below the recommendations given for achieving hypertrophy (30/40-70 seconds).
The only, and fairly accurate, way to measure real progress and make sure your muscles are actually under tension for an adequate amount of time is to time your sets. You should keep track of the duration of each set first, and only then count the reps.
Translator’s note: I recommend that readers remember a set duration of 30-70 seconds. It has long been a good benchmark. Any set that lasts less than 30 seconds is strength-oriented in nature. From 30 seconds up to that 70 seconds is the “sweetest” set duration for hypertrophy for those of us who are genetically average. Admittedly, someone with a predominance of fast-twitch muscle fibers (perhaps even 70-75%) benefits from sets of up to 30 seconds. But such men are genetic phenomena. Once again, we “mere mortals” should definitely get our set duration to at least over 30 seconds.
I’m not trying to claim that this should apply to every exercise. Heavy basic exercises might well stay in that strength-oriented range, but make sure that all your other exercises don’t end before 30/40 seconds either!!!
The fact is, however, that most lifters fall below this most effective set duration. As a result, they don’t induce the most effective, maximal hypertrophy either.
It’s also important to know that TUT actually varies from muscle to muscle, even within the same individual.
Translator’s note: The most typical mistake made here is trying to compensate for the problem (I’d even say unknowingly) with more volume. That is, because the sets are short, the muscle doesn’t even get fatigued. Then you feel you’ve got strength left and add sets. The right approach would be the opposite: make the set longer, into that effective hypertrophy duration, and take the last bit out of the muscle. In that case you simply wouldn’t be able to add more sets, and exhaustion is reached through a small number of intense sets. Endless sets, on the other hand, cut into the muscles’ growth potential, shorten recovery time, and in the end our muscles simply don’t grow.
Although we’re talking about an average TUT that would suit everyone, we mustn’t forget that in the end it is individual too, depending heavily on our individual fiber composition, motor skills and other factors.
Put as simply as possible, the faster a muscle fatigues, the greater its NEUROMUSCULAR CAPACITY/EFFICIENCY (neuromuscular efficiency), THAT IS, THE ABILITY TO MAKE A LARGE NUMBER OF MUSCLE FIBERS CONTRACT QUICKLY AT THE SAME TIME. AND AS A RULE, SUCH NEUROMUSCULAR CAPACITY IS DRIVEN BY FAST, LARGE MOTOR UNITS (LARGE NERVE CELLS THAT INNERVATE LARGE, FAST, STRENGTH-PRODUCING MUSCLE FIBERS).
The more slowly a muscle fatigues, the lower its neuromuscular capacity, and as a rule it is a muscle in which the majority of fibers are either slow-twitch or mixed-type.
All in all, the matter is worth investigating, and every serious lifter should experiment in this area to find the most favorable TUT for each muscle and the resulting rep count.
Translator’s note: I ran this experiment myself too, in my chest workout. It was honestly quite startling to realize that my sets of pressing movements ended long before 30 seconds had ticked by. On presses, my sets lasted 20-25 seconds on average, and I should say that when I got a set up to 25 seconds, for me that was already a REAL STRETCH :))! After a brief look into TUT, I deliberately tried doing a few workouts in a way that consciously follows the classic rule of a 2-3 second lowering phase and a 2 second lifting phase. Dear fellow lifters, hand on heart, that 2-3 seconds down, 2 seconds up, which is in fact the assumed rep tempo of every training program, is REAL NEGATIVE TRAINING for me. And I honestly admit that on presses (pressing exercises) I could never train at such a tempo. It’s too slow for me. While my working weights on the bench press are usually in the 120-150 kg range, with that 2-3 down, 2 up tempo, 70-90 kg was the most I could press. The situation even made me laugh at myself :)!
In a way, it makes me wonder whether fast-twitch muscle fibers really might dominate in my chest muscles??? I’ve actually always used heavy weights on presses, and thinking back, those sets never lasted long. It’s quite common for me that A SOLID TEN SETS ARE ENOUGH FOR THE CHEST, AFTER WHICH IT IS EXHAUSTED AND THOROUGHLY WORKED.
At the same time, I should note that all my flyes from the different inclines and the pec deck fell into the 40-60 second range, which is perfect, I’d say, considering what was mentioned above. I’ve always done flyes slowly, feeling the negative phase and the stretch.
Go figure???
But from all this I can draw one definite conclusion: the basis of my success has perhaps been that I’ve always used sets of varying duration. I think that if you approach your training this way, it’s forgivable, and I’d even say justified, that for each muscle there is an exercise with a shorter duration that stimulates the fast-twitch muscle fibers. The resistance is high, the movement fast and explosive. As a rule, that exercise would be the main basic exercise for the muscle group (legs: squat, chest: press, etc.). But it would certainly be important not to perform the whole workout this way, on the back of fast, short sets that don’t last. THIS IS ESPECIALLY IMPORTANT IF YOU DON’T USE PERIODIZATION.
So there are exercises that are deliberately high-resistance and explosive, with a set under 30 seconds, and there are exercises where the set definitely always lasts longer than 30-70 seconds, and occasionally even more!
In closing, I urge you to time your sets. I’d bet that many will come to the same realization as I did. I believe that the vast majority “bang out” their 8-12 reps and think that’s how it’s supposed to be, while that 10-rep set may last only 20 seconds. Think about it. You may claim that you progress with that too, but think about it, and try it: how much further might you progress with the right set duration???!!!
I used material from an article published on Bodybuilding. Com, “Why Everyone Is Wrong About Reps!” by Gregg Gillies
Author: Janar Rückenberg
Come and train! ArtGym
