Search "how to build muscle," and you get 322 million results. That's a lot of information to sift through. Some websites tell you what exercises to do, some tell you what food to eat, some what supplements to take. Unfortunately, their recommendations aren't always the same or even in agreement.
One site touts body-weight exercises, another advocates free weights. Eat more protein, urges one site. Don't each too much protein, warns another. Make sure you get protein right before bedtime, counsels a third.
How do you know which advice to heed? To help, we consulted two experts: Wayne Westcott, professor of exercise science at Quincy College, and Keith Baar, professor of molecular exercise physiology at the University of California, Davis. They pinpoint the most common muscle-building mistakes and how to fix them.
1. Not Giving Your Muscles Enough Recovery Time
The number one mistake Westcott sees is people not resting enough between workouts. After a hard workout, he says, you need 72 hours to fully recover. (As evidence, he cites a comprehensive series of studies published in May 2003 in The Journal of Strength and Conditioning Research.)
Does the prospect of waiting three days between workouts unsettle you? Not to worry. The research doesn't dictate working out twice a week, Westcott says. "It just means that you wouldn't want to work the same muscle groups."
Westcott suggests a grouping traditionally followed by muscle builders: chest and shoulders every Monday and Thursday, lats and biceps on Tuesday and Friday and legs and abs Wednesday and Saturday. This arrangement lets you pump iron almost daily while giving each muscle group a full 72 hours to recover.
2. Focusing on Quantity Over Quality
People overestimate how much work building muscle takes, Baar says. "They think it takes tons and tons of repetitions and lots of volume and lots of time." But one set can give you 95 percent of the muscle gain you'll get from a given exercise. The trick is to do it until fatiguing.
Baar points to the research of Stuart Phillips, a kinesiology professor at McMaster University, for support. One study Phillips coauthored, published by the Journal of Applied Physiology in July 2012, showed that the amount of weight 21-year-old men lifted made no difference as long as they went until failure.
Another July 2019 study, which appeared in The Journal of Strength and Conditioning Research, corroborated those findings. The researchers divided women age 18 through 27 into two groups, each of which did the same exercises (usually to failure) but with different weight loads. By the end of the 12-week study, both groups had made similar gains.
According to Westcott, who's served as a consultant to NFL strength coaches, some football teams are wise to this stuff. "The teams I worked with were high-intensity teams," he says. "They didn't spend a lot of time at the gym, but they worked really, really hard and they went through several levels of muscle failure."
Instead of following professional football's standard three-hour daily workout regimen, the Washington Redskins and five other teams Westcott assisted went to the gym two or three times a week for 45 to 60 minutes per session. While there, they'd do only one set of an exercise, focusing on intensity. This approach worked, Westcott says — the Redskins won four Super Bowls during his time with them.
3. Avoiding Weight Machines
Maybe you've heard free weights are better because they engage stabilizer muscles. Or that they allow for "functional" exercises resembling everyday movements. Or maybe you're just embarrassed to use a shoulder press machine when you could be doing the same exercise with a barbell.
Whatever the reason, such reluctance is misplaced. "There's absolutely no drawback to using a machine," Baar says. While free weights may activate small stabilizing muscles, the activation isn't necessarily desirable. If your goal is lifting to failure and growing a specific muscle, Baar says machines are better.
He cites glutes as an example. The best way to develop them isn't with freestanding squats because the small muscles in your back will fatigue before your glutes do. You'll see superior results by targeting them on a leg press machine, he says.
4. Not Eating Enough Protein
"Muscles are made of protein," Westcott says, so it's crucial that you get enough. The recommended daily allowance is 0.4 grams per pound of target body weight. If you're trying to burn fat and build muscle at the same time, Westcott recommends 0.7 grams.
He advises consuming protein shortly before or after a workout. While some studies suggest timing doesn't matter, Westcott's own research shows consumption within 30 to 60 minutes of working out benefits you. The International Society of Sports Nutrition is on his side, describing the combination of resistance exercise and protein consumption as "synergistic."
5. Not Getting Enough Sleep
"Your muscles rebuild during the sleep cycle," Westcott says. According to the National Sleep Foundation (NSF), your slumbering body produces muscle-building hormones, repairs tissue and ups blood flow to muscles. You should be getting about eight hours of shut-eye a night, the NSF states.
Happily, exercise improves your sleep, but beware of late-night workouts. Your body temperature naturally drops before bedtime, preparing you for rest. But exercising raises body temperature, which can make falling asleep difficult. This doesn't always hold true for everyone — the NSF notes that some people sleep just fine after gym visits. But to play it safe, put at least two hours between your workout and bedtime.
- The Journal of Strength and Conditioning Research: A series of studies--a practical protocol for testing muscular endurance recovery.
- Journal of Applied Physiology: Resistance exercise load does not determine training-mediated hypertrophic gains in young men
- The Journal of Strength and Conditioning Research: Low-Load vs. High-Load Resistance Training to Failure on One Repetition Maximum Strength and Body Composition in Untrained Women
- International Society of Sports Nutrition Position Stand: protein and exercise
- National Sleep Foundation: How Sleep Adds Muscle