The number of sets and reps you do, and the amount of weight that you lift, depend on what muscle property you are trying to develop. Muscles have four properties:
- Strength (the amount of force a muscle can produce)
- Size (a muscle’s diameter)
- Endurance (a muscle’s ability to keep contracting against resistance)
- Power (a muscle’s ability to produce both strength and speed)
How to develop each property
To develop each property, you have to perform a different number of sets and reps. You also have to lift a different amount of weight. The following guidelines, summarized in Table 1, provide a generalized outline of how each muscle property can be developed.
|Sets per exercise||2–6||3–5||3–6||2–3|
|Reps per set||2–6 (low)||1–5 (low)||6–12 (moderate)||> 12 (high)|
|Weight (% 1RM)||Very heavy (> 85)||Heavy (75–90)||Heavy (67–85)||Low–Moderate (< 67)|
|Rest between sets||2–5 min||2–5 min||30–90 s||< 30 s|
|Table 1. Guidelines for developing different muscle properties. 1RM = one-repetition maximum; min = minutes; s = seconds. *Training tempo defines the number of counts for the concentric, hold, and eccentric phases of the rep; e.g. 1:2:2 is 1 count concentric, 2 counts hold, and 2 counts eccentric.|
What is 1RM?
Notice that the amount of weight you have to lift to develop each property is presented relative to your 1RM, which stands for one-repetition maximum (or one-rep max for short). Your 1RM is the heaviest weight that you can lift in an exercise for one, and only one, rep using proper form. Being aware of your 1RM for a given exercise can be useful for two reasons:
- You can use it to work out how much weight to lift for the exercise (although this isn’t necessary, as explained below).
- It allows you to notice and measure an increase in strength. If your 1RM increases, you know that you have become stronger. If it doesn’t increase, it means that you have hit a plateau.
You can find your 1RM for a given exercise by working up to it using increasingly heavier weights, or by estimating it by finding a weight with which you can perform three reps (which is safer) and consulting a 1RM chart. By convention, the weight with which you can perform one rep is known as your 1RM, the weight with which you can perform two reps is called your 2RM, and so on.
Note, however, that you don’t have to know your 1RM for an exercise in order to determine the amount of weight you have to lift for that exercise. The rep range you have to follow actually tells you the amount of weight you have to lift. For example, the rep range to develop size is six to 12 reps. This means that you have to use a weight with which you can squeeze six to 12 clean reps. If you can’t do six clean reps, it’s too heavy; if you can easily do 12 clean reps, it’s too light. In other words, by the sixth or twelfth rep, you should be nearing failure to perform clean reps. And by “clean”, I of course mean using proper form.
How do you develop muscular strength?
As you can see from Table 1, training for strength involves performing two to six sets per exercise, each consisting of two to six reps, using very heavy weights (more than 85% of your 1RM). Because the weights are very heavy, the rest interval between sets is relatively long (two to five minutes) to allow for sufficient recovery. Lifting very heavy weights ensures that virtually all Type I, Type IIa, and Type IIb muscle fibers are recruited. However, mostly muscular strength and size are developed; muscular endurance is not developed due to the small number of reps. And the gains in size that you make with this rep range are not optimal. (Note: Muscle fiber types and their properties were covered in the lessons Muscle structure and How muscles work.)
How do you develop muscular size?
Training for optimal size involves performing three to six sets, each consisting of six to 12 reps, using heavy weights (67%–85% of your 1RM). This kind of training will recruit most Type I, Type IIa, and Type IIb muscle fibers, leading to great gains in strength and size but limited gains in endurance due again to the relatively small number of reps. More size is built than with training for strength because the muscle sustains more microdamage as a result of the higher workload and the extra time under tension. This kind of training is also more effective at increasing the body’s production of testosterone and growth hormone, which are important for building muscle.
How do you develop muscular endurance?
Training for endurance involves performing two to three sets, each consisting of 13 or more reps (often 15 to 20), using low to moderate weights (less than 67% of your 1RM). This kind of training will mostly recruit Type I muscle fibers, thus helping you to develop good endurance but limited size and strength. Because the rest interval is short and the number of reps is high, sets are kept to a maximum of three to avoid overtraining.
How do you develop muscular size, strength, and endurance?
If you perform a mixture of low-rep training with heavy weights and high-rep training with moderate weights, you will recruit and strengthen the properties of all muscle fiber types and therefore develop good size, strength, and endurance.
How do you develop muscular power?
Power is developed by rapidly performing one to five reps using a heavy weight (75% to 90% of your 1RM), which recruits all fiber types but calls mainly on the properties of Type IIb muscle fibers. If performing just one to two reps, use 80% to 90% 1RM; if performing three to five reps, use 75% to 85% 1RM. The number of sets is kept between three and five, with a two- to five-minute rest between sets. Power-building exercises involve generating a great force as rapidly as possible and are therefore characterized by explosive movements. Such exercises can be dangerous for beginners, so they are only recommended for intermediate and advanced lifters. To avoid injury, the exercises must be performed using optimal form, after fully warming up.
Differences between small and large muscle groups
I should make it clear at this point that small muscle groups need fewer sets than do large muscle groups. Therefore, stick to the lower end of the set range for small muscle groups and the higher end of the set range for large muscle groups. What’s more, small muscle groups don’t require as much weight. Therefore, stick to the higher end of the rep range (and therefore the lower amount of weight) for small muscle groups and the lower end of the rep range (and therefore the higher amount of weight) for large muscle groups.
The reason that you shouldn’t go too heavy on small muscle groups is that they are usually trained using isolation exercises, which, by definition, involve a single joint, and you don’t want to put too much pressure on the joint. It’s less risky to go heavy with compound exercises, which, of course, involve more than one joint. What’s more, the heavier the weight, the more the surrounding muscle groups will get involved in the exercise, so the goal of isolating the muscle will be defeated.