Your Ideal Rep Range
How many repetitions produce optimal muscle growth? We let the high- and low-rep experts present their cases.
Feel like instigating a heated verbal brawl? Enter a room filled with strength coaches, personal trainers and exercise physiologists and ask how many reps per set you should be doing to gain mass. Then take cover press conferences during the O.J. trial boasted more decorum than the furor that would ensue.
High reps, medium reps, low reps have been touted as ideal ways to build muscle. Stalwarts in the exercise biz argue with deep-rooted passion, but incontrovertible conclusions are rare, leaving the average Joe wondering, Okay, which range should I use to get bigger?
Here we build separate cases for high, medium and low reps and render a verdict on which is the best choice for increasing muscle mass. The weight room will now come to order.
Suspect No. 1: High Reps (15 or more)
If you've ever tried a set of 15 or more reps, you know it can be difficult. If you're unaccustomed to training in this zone, you'll find your muscles fatigue quickly, and 40 pounds starts to feel more like 100 by the final rep.
Sets that stretch past 15 reps, though, have one major drawback: The amount of weight you can handle isn't heavy enough to recruit fast-twitch type-2 muscle fibers. So what, you ask? Simply put, type-2 fibers are where the potential for growth resides, and they respond only to heavy weights at least 75 percent of your one-rep max.
High-rep training is, however, an excellent means of increasing muscular endurance. If you're after sports-specific adaptations such as a throwing arm for softball that can hold out for more than half an inning or legs that will carry you to the finish line of a marathon high reps can help. But if size is paramount, high reps won't get it done, especially if the preponderance of your training lies in this zone.
Suspect No. 2: Low Reps (five or less)
In weight training, one adage has stood the test of time: To get big, you have to get strong. Taking that to an extreme, many lifters adopt a powerlifting approach, coupling very heavy weights with low reps. Take a look around your gym, and you're likely to find an aspiring bodybuilder or two struggling through sets of squats or bench presses with weights at or near their one-rep maxes.
This method is a sure strength builder, and if you take a close look at any successful powerlifter, you'll notice the added mass in his frame. However, low-rep training has one significant shortcoming: Muscle-fiber stimulation, and thus growth, is correlated closely to the amount of time a muscle is under tension. Short, intense sets of 15 seconds or less will develop strength, but they simply aren't as effective in prodding a muscle to grow as sets of 30 to 60 seconds.