Can Some People Naturally Build Muscle Faster Than Others?

7 min readYou just started a workout routine with a friend, and they’re seemingly packing on muscle overnight while you’re waiting for results. If this has ever happened to you, you’re not imagining things—according to science, not everyone builds muscle at the same rate.“If you put a group of people on the exact same [resistance] training program, the range of responses is striking,” says Stuart Phillips, PhD, a muscle researcher and professor of kinesiology at McMaster University. “Some gain a lot [of muscle] and some gain a little.” The bad news: The way your body responds to exercise is based on some factors that are out of your control, like genetics. The good news: There are some variables that are in your control, like your training and fueling plan. Plus, no matter the speed at which it happens, everyone is capable of building muscle, Phillips says.Meet the experts: Stuart Phillips, PhD, is a muscle researcher and professor of kinesiology at McMaster University. Brooke Taylor, CPT, is a certified personal trainer, creator of the Brooke Taylor Fit App, and owner of Taylored Fitness NY LTD. Mark Kovacs, PhD, CSCS, is an exercise physiologist, longevity and human performance specialist, and founder of the Kovacs Institute. Natalie White, CPT, is a certified personal trainer and founder of Strong With Nat.That’s encouraging, especially given how valuable muscle is for overall health. “Building muscle is one of the most important investments we can make in our long-term health, mobility, and longevity,” says Brooke Taylor, CPT, a certified personal trainer, creator of the Brooke Taylor Fit App, and owner of Taylored Fitness NY LTD. “Muscle provides support and stability around our joints, improves balance and posture, helps protect against injury, and allows us to continue doing the activities we love as we age.”So, how does muscle growth actually work? Ahead, experts break down the science of muscle building, which factors influence your results, and how to maximize your gains.How Strength and Muscle DevelopsGeneticsGenetics influence many of the factors that affect how easily you build strength and muscle, including your body type, metabolism, muscle fiber makeup, and how quickly your body recovers after a workout, says exercise physiologist Mark Kovacs, PhD, CSCS. They can also affect how your body responds to muscle-building hormones and repairs muscle tissues after exercise, which can influence how well you adapt to training over time, he explains.One of the biggest genetic determinants of the speed at which you can build muscle and strength is your ratio of muscle fibers. Fast-twitch fibers are designed for powerful, explosive movements like sprinting or powerlifting and have a greater potential for muscle growth, Kovacs explains. Slow-twitch fibers, on the other hand, are better suited for endurance activities like long-distance running.As a result, those with more fast-twitch fibers may gain muscle and strength quicker than those with slow-twitch muscle fibers—even when following similar training programs. However, while your natural muscle fiber makeup provides a starting point, some research suggests that consistent training can modestly shift your muscle fiber profile. There’s also no practical way to know your exact muscle fiber makeup without doing a muscle biopsy, and even that isn’t perfectly accurate.All in all, your genes aren’t everything, as there are so many factors that play an important role in muscle-building (see below). “Genetics set the range of what’s possible, but your training and nutrition determine where in that range you actually land,” Phillips says.AgeYounger people—typically those younger than their mid-30s—often gain strength and muscle more quickly because they tend to recover faster between workouts, Phillips says.According to Taylor, this is because younger adults generally have higher levels of muscle-repairing hormones and a more robust ability to synthesize new muscle proteins after training. So, they can typically tolerate higher training demands and bounce back faster, which may accelerate progress. (By contrast, a healthy older adult who completes the same strength-training program may need an extra day or two of recovery between sessions.)But no matter your age, there are ways to prioritize your recovery so you can return ready for every workout (more on that later).Training ExperiencePeople who are new to strength training often see rapid progress during their first few months in the gym—a phenomenon commonly known as “newbie gains.” This happens because the body is learning and adapting to a new and challenging stimulus very quickly, says Phillips.Start your fitness journey with our exclusive beginner workout planAs you get more training experience, your brain gets better at activating the right muscles and coordinating movement, making you stronger. At the same time, your muscles begin growing in response to the new training stimulus. Together, these changes can lead to noticeable increases in strength and muscle size in as little as two to three months. However, someone who has been training consistently for years may take three to six months to achieve gains that would be equivalent at their level.Training QualityWhen it comes to building strength and muscle, the quality of your training—like, how well you execute each exercise with proper form and control, all at a level that challenges your body—is key.Building strength also requires progressive overload, or gradually increasing the demands of your workouts over time through lifting heavier weights, pushing for more reps, or tacking on an extra set. Every workout signals to your body that your muscles need to adapt by becoming stronger, larger, or more efficient. On the flip side, if your workouts never become more challenging, your body has little incentive to keep adapting and building strength, which can ultimately slow muscle growth and eventually lead to a plateau, Taylor says.NutritionWhen you train, you create small amounts of stress and damage within your muscle fibers. “If you don’t eat enough food, your body won’t have the necessary resources to build muscle,” says Natalie White, CPT, a certified personal trainer and founder of Strong With Nat. Protein provides amino acids, the building blocks your body uses to repair and construct new muscle tissue, says White. Carbohydrates also help support the process by replenishing the glycogen stores that your muscles rely on for energy during training and recovery, she says.So, before and after a challenging strength workout, White recommends consuming a meal containing lean protein, whole grains, and vegetables. Over time, this cycle of training, recovery, and rebuilding will help drive muscle growth.Recovery and SleepFun fact: Most muscle growth happens after a workout, not during it. Research shows that sleep is when your body repairs damaged tissues, restores energy levels, and releases hormones that support muscle growth and recovery, says Phillips. This means poor sleep can reduce workout performance, impair recovery, and make it harder to build strength and muscle over time. “So, if you skimp on sleep, you blunt the very adaptation you trained for,” he says.While some of the above factors are out of your control, everyone is capable of building muscle—even if it’s at a slower rate than your gym buddy. “I’ve never seen someone who trains sensibly and eats enough protein who can’t get meaningfully stronger,” says Phillips. Here’s how to do it:Prioritize progressive overload. “The body adapts to the demands placed upon it, so your workouts need to evolve over time through increases in resistance, repetitions, sets, tempo (how fast or slow you perform each part of an exercise, such as lowering and lifting the weight), or complexity,” says Taylor. This steady progression allows the body to gradually become stronger while reducing the risk of injury.A good rule of thumb: When you can complete 10 to 12 reps with solid form and still feel like you have more in the tank, it’s time to increase the weight or add a few more reps.Eat enough protein. Your individual protein needs will vary based on your training intensity, activity level, age, and hormonal shifts, especially during perimenopause and menopause. But if your goal is to build muscle, Kovacs recommends aiming for about 1.4 to 2.2 grams of protein per kilogram of body weight per day, or roughly 0.6 to 1.0 grams per pound. For example, a 150-pound woman (or 68 kilograms) would aim for anywhere between 95 to 150 grams of protein per day.Protein powders and bars can be convenient when you’re in a pinch, but Taylor says the bulk of your protein should come from whole food sources like chicken, lean beef, tofu, beans, fish, and turkey.Promix Whey Protein PowderCredit: Jeff HarrisAloha Plant-Based Protein Bars Variety PackNow 31% OffCredit: CourtesyThorne RecoveryProCredit: Jeff HarrisBarebells Protein Bars Variety PackCredit: CourtesyDon’t skimp on sleep. Poor sleep can interfere with muscle repair, hormone function, and training performance, Kovacs says. So, it’s important to get seven to nine hours of quality rest each night. Plus, research shows that consistently prioritizing sleep can improve your energy levels, workout quality, and overall progress over time.Stay consistent.“Muscle is built slowly, so the people who you may think have ‘great genetics’ are very often just the people who keep showing up,” Phillips says. He recommends two or three strength training sessions per week: three full-body sessions or one upper body, one lower body, and one full-body session.And try your best not to measure your rate of progress against someone else’s. It’s “a fast track to frustration, so compare yourself to where you were last month instead,” Phillips says.While the rate at which you build muscle depends on the above factors, Taylor says most people notice measurable strength gains within one to two months of consistent training. Visible muscle definition, however, typically takes a bit longer, with noticeable changes often beginning around the two-month mark and continuing over time.Just focus on showing up day after day and following a well-designed training plan. Strength and muscle gains may not happen overnight, but small improvements add up over time. Those who stay the course are often rewarded with the best long-term results.Andi Breitowich is a freelance writer who covers health, fitness, relationships, beauty, and smart living. She is a graduate of Emory University and Northwestern University's Medill School of Journalism. Her work has appeared in Women's Health, POPSUGAR, Food & Wine, What To Expect, Cosmopolitan, Men's Health, and elsewhere. As a former collegiate pole vaulter, she loves all things fitness and has yet to meet a group workout class she doesn't like.