This question is one of the most frequently asked in gyms and on the Internet. So how many reps do I need to do in one set: 3-6, 6-8, 12-16 or 20-30? Unfortunately, a number of repetitions (for instance: how many bench presses or squats you can do without a break) is only a partial answer to your question. A number itself means little without analysing the speed of your exercise. The tempo means how quickly you can lower the weight or lift it in a constant movement, without stopping.

The same weight, the same volume (number of sets x number of repetitions) and two different tempos may mean two completely different workouts.

For example, do squats on one session but introduce one single change - stop the motion in the critical moment, at the very bottom. If your flexibility and proportions of your limbs allow it, go as low as possible (advanced sportsmen would be able to touch their calfs with the back of their thighs). Hold on like this for 1-2 seconds. Now this single pause dramatically changes the whole training. The weights you used so far, ranging within 75-80% of your maximum can cause serious difficulties. Yet another drastic change is a slow motion exercising. The introduction of several pauses (during the movement down, at the bottom, and while lifting) will also make you reduce the weights you used, even by 50%! Want more tricks? A double bottom will do. Move down to the bottom, move up slightly, and then deepen your squat.

It's the same with the most favorite exercises of all muscle men: bench press (on a horizontal bench). An introduction of small changes, such as stopping the weights on your chest (the same as in the powerlifting competition) can lower your score by 20-30 kgs! Plus a ban on lifting your buttocks and shoulders while pressing, prohibition on a movement down (also unequal pressing) and suddenly it turns out that the records broken at your gym must be reduced by 30-40 kilos and more. In order to increase the work your muscles do slower the movement down to your chest (2 seconds), stop the weight on the chest. You can introduce also another encumbrance: that is a pause in the middle of the lifting motion.

Similarly, standing barbell curls and dumbbells curls. Many of those who visit gyms complain about lack of "feeling of strain in muscles" while working on their biceps. Their movements are chaotic and jerky, their scope: partial. During exercises done this way, you will feel the work of... your stomach muscles, legs and back. Targeted biceps will be engaged only a bit. Use a weight that will allow you to move without "swinging" or "rocking" of your body, slow down your movement down to 2-3 seconds, lift the weight quickly but control the movement, hold the weight while your muscles are contracted at the end of the concentric phase. You'll be amazed at how a half of the previously lifted weight and a half less volume can make you worn out. These "tricky" movements should be included in your workout plan, but certainly not for most people. If you have too little training experience, better wait.

Getting back to the merits, you can come across two ways of codification: full and shortened.

Full is 4 digits and letters: successively 1234:

  1. eccentric phase (lowering, in seconds)
  2. hold at the bottom (in seconds)
  3. concentric phase (in seconds or X = as soon as possible),
  4. hold at the top (in seconds)

What are the succesive digits?

1. The eccentric phase = for bench press or shoulder press: lowering of the barbell in the direction to your chest; for squat: movement down; for deadlift: lowering the weights to the ground; for pull ups: body lowering; for barbell and dumbbells curls: hands lowering, for rowing: hands lowering, etc.

2. Hold = for squat: stopping at the bottom (or in any part when you reverse your movement); for bench press: holding the weights on your chest; for dumbbell flyes: stopping your hands with dumbbels at the full stretch; for dips: holding the body in the lowest position, etc.

3. The concentric phase = for bench press: pressing the barbell up; for deadlift: lifting the weight from the ground, for dips: movement up; for shoulder press: pressing the weight over your head; for pull ups: lifting of your body up; for rowing: moving the weight up to your chest or stomach. Note: here you can often come across the X (X = as soon as possible).

4. Hold at the top - depending on the type of exercise it may be: for bench press: holding the weight over your chest, elbows straight; for clean and jerk, snatch, shoulder press: holding the weight over your head, elbows blocked, for sit-ups, pause e.g. half-way up,

You can read 40X0 (for example for a squat) as: 4 = 4 seconds of lowering (moving down), 0 = no hold at the bottom, X = move up as soon as possible, 0 = immediately do the next repetition. 3020 means: 3 second of hands lowering (eg. for barbell curls or French press), no hold, 2 seconds of hands lifting, immediately do the next repetition. Pull-ups: 10 sets x 10 reps, 40X0 pace, rest: 90 seconds - that is you lower your body for 4 seconds, very slowly, do not stop at the bottom or at the top, but lift yourself as soon as possible.

American scientists investigated how three types of training with varying number of repetitions influence muscle mass building of men. 32 untrained men aged 22.5 (+/-5.8 years), height 178,3 cm (+/-7,2 cm) and weight 77,8 kgs (+/-11.9 kgs) participated in an 8-week strength training. They were divided into three groups: low reps (9 men) who did around 3-5 reps, 4 sets with 3-minute breaks between sets and exercises; medium reps (11 men), doing 9-11 reps in 3 sets with 2-minute breaks, and high reps (7 men) who would do 20-28 reps in 2 series of with a 1-minute break. There was also a control group of 5 men. They would do only 3 exercises: leg press, squats and legs extension. For the first 4 weeks the participants worked out 2 days a week, the next 4 weeks: 3 days a week. Maximum strength (1 repetition) was measured, as well as local muscle endurance (max reps with the weight of 60% of max) and various physiological parameters (e.g. VO2 max, pulmonary ventilation, maximum aerobic power - training till failure). Measurements were taken before and after the experiment. In addition, samples of muscle composition were analyzed in order to check types of muscle fibers, muscle growth (cross section), changes in the amount of capillaries. Results? No surprise – the biggest strength increase was noted in the low reps group, number of reps with the weight of 60% of the maximum was the highest in the high reps group. In terms of the length of aerobic workout (training till failure) changes occurred only in the high reps group (20-28 repetitions). There was an increase of all three types of muscle fibers (I, IIa, and IIb) in the group of low and medium reps. The muscle growth was not observed in the control group (which didn't do any workout) and the high reps group. However, the amount of IIb and IIa muscle fibres decreased for all three groups of particiants. Despite the fact that the described changes occurred in each group, the largest progress in muscle development was observed in the groups with low and medium number of repetitions.

Conclusions? For better muscle growth apply low and medium range of repetitions in your workout. According to literature, 8-15 repetitions in a series of 75-85% of your max will be optimal for most sportsmen. It should be remembered, though, that the same number of reps with the same weight but different tempo can bring completely different effects. For muscle growth it is also important how long muscle fibers remain under tension (TUT = time under tension), and not merely the number of repetitions or applied weight themselves. It should not be forgotten that of utmost importance are also the rest break between each sets, proportions of muscle fibers in trained parts of your body, range of motion (widely understood technique which engages appropriate muscles) and your nervous system adaptive capacity. What is important for good strength and mass gains is a proper diet, hence the slogan: "you do the mass in the kitchen, not at the gym."