Very often, when you enter a gym, you can guess the repetition range a trainer will use based upon his physique. If a person is big, without definition, and very strong, it’s a safe bet that he’s employing a very low repetition range. On the other hand, if the person training is lean, has some good muscle, but looks like he could run a marathon with no trouble, then it’s likely he uses a higher range. Let’s check out the four primary repetition ranges, and examine the movements and bodybuilders most likely to be associated with them.

Training for Power (1-3 repetitions)

If you’ve seen a powerful offensive lineman knock another man off his feet, or a strongman lift a 250-pound Atlas ball over his head, then you have seen the results of training for power in action! The use of very heavy weights for just a few repetitions will lead to terrific gains in power, defined as strength times speed.

Training for Strength (4-8 repetitions)

Powerlifters love this repetition range, with the 5-rep set being king. The use of very heavy weights for 4 to 8 repetitions challenges not only the muscles, but the tendons and joints as well. It also requires you to use a bit of swing in the movement. Remember, the goal of powerlifters is to move significant amounts of weight, and they aren’t concerned with the mirror. Any time you’re lifting and you hit the 10th or 12th repetition, it’s time to add some more weight to the bar, if you seek powerlifting success.

Training for Hypertrophy (8-15 repetitions)

This is the repetition range employed by most bodybuilders. If your goal is to make gains in lean, muscular mass, then you should be doing at least eight repetitions during most sets. This will stimulate a healthy mix of slow and fast-twitch muscle fibers. If you find yourself going beyond 12 repetitions, it’s safe to say you’re using too little weight. The goal of bodybuilding training is hypertrophy. You work to flush a great deal of blood into the muscle group using as heavy a weight as possible.

Training for Muscular endurance (15+ repetitions)

Many athletes requiring muscular endurance, such as marathoners, basketball and soccer players, or those who partake in triathlons, will train in the 15+ repetition range. This stimulates the slow-twitch muscle fibers, which aren’t normally trained when using heavier weights with much lower repetition ranges. For this reason, it’s not an altogether bad idea of bodybuilders and powerlifters to occasionally train for some muscular endurance, to assist them in performing their normal workouts better.

It’s important to use a mix of repetition ranges in your training to ensure you stimulate as many muscle fibers as possible. At the same time, you should train mostly in a rep range which best suits your goals. If you plan to compete in powerlifting meets, you don’t have much use for 15+ rep days. Likewise, if you’re a long-distance runner, there isn’t much safety or sense in trying one repetition maximums. Train based upon your goals, but keep the other methods around for variety.