How long it takes to add 0.5kg of muscle, according to trainers

Building muscle is crucial for overall well-being...but it isn’t as easy as you may think. In fact, physical therapist Shannon Ritchey is on her own journey of adding muscle—the new mum has a goal to add nearly 2.5kg —and she’s given herself a full year to do it so as not to overwhelm her body or life with the goal. It’s all about 'gentle consistency', she says, and finding ways to sustainably build muscle. Enter: her realistic timeline.

As for why you'd want to gain muscle in the first place: It might be the key to longevity, according to a review in Aging and Disease. Muscular strength, which naturally declines with age, is 'inversely and independently associated with all-cause and cardiovascular mortality', according to the review. This means that as muscle decreases, risk of issues like stroke, hypertension, metabolic syndrome, type 2 diabetes, Alzheimer’s, and Parkinson’s have been found to increase.

Plus, muscle helps insulin sensitivity, boosts energy levels, changes body composition, and improves metabolic health, says Ritchey, who is also the founder of Evlo Fitness, an online strength training platform. It’s also there to make all of your everyday functions—from opening a heavy door to lifting your children into their carseat—much easier.

Meet the experts: Shannon Ritchey, DPT, PT, is the founder of Evlo Fitness and host of The Dr. Shannon Show podcast. Winnie Yu, DPT, PT, CSCS, is a sports and orthopedic physical therapist at Bespoke Treatments in New York City.

While it’s never too late to build muscle, 'the earlier you can start, the better,' Ritchey says. This is because as you get older, you start to lose muscle and it gets harder to build. Beginning at age 30, your body naturally starts to lose 3-5% of its muscle mass per decade, according to the U.S. Department of Health and Human Services’ Office.

So, how long exactly does it take to add even one pound of muscle to your body? Experts weigh in—and share actionable advice for fast-tracking your muscle growth.

What makes muscles grow?

Muscles are soft tissues in the body that can relax and contract, says Winnie Yu, DPT, PT, CSCS, a physical therapist at Bespoke Treatments. You use them for pretty much every movement, not just lifting weights at the gym.

When you stimulate a muscle beyond its tolerance (meaning you lift something heavier than you’re used to, whether it’s a dumbbell or that super heavy Amazon package you just got delivered), small, temporary damages occur. This is why you feel sore. Then, during rest, and most importantly, sleep, your muscles patch up the damages, making them bigger and stronger, says Yu.

What factors affect how fast muscle grows?

It’s not just about what you do in the weight room. One of the biggest factors that affects how quickly you can build muscle is whether you’ve done it before.

For beginners, visible muscle growth happens in about eight to 12 weeks, but if you’ve worked out before, it can be quicker since you already have certain neuromuscular pathways established, says Ritchey. 'Your body remembers', she says. In the beginning, it’s about your body and nervous system learning how to contract the muscles before you can really load them with enough weight really make a difference.

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Another important component of muscle growth is nutrition. If you have a goal of packing on half a kilo of muscle, you’re going to need to get your protein in, Ritchey and Yu agree. (More on protein, next.) You’ll also likely need to increase the amount of food you’re eating by about 200 to 500 extra calories per day, which you can get in with a snack, says Yu.

Lastly, consider the frequency of your workouts and total number of sets and reps. You don’t need to spend as much time as you’d think to make a difference—only about twice a week and at least one hard set per muscle group, though Ritchey says four to eight will result in better, faster gains.

Overall, it can take a few weeks to build half a kilo of muscle, and that’s also because you want to do it sustainably, says Yu. It’s important to build a routine and cadence that you can stick to, gives you plenty of time to rest and recover, and fits into your lifestyle and other responsibilities.

Exactly how to build half a kilo of muscle

Actually measuring one pound of muscle can be tough, says Ritchey. If you don’t have access to a DEXA scan or other body composition calculators to track the actual changes you’ve made, you can focus on how you feel.

Half a kilo of muscle might sound like a lot, but it probably won't look like a huge change, especially dispersed across your body. Half a kilo of muscle 'is a lot less noticeable than you would think it is appearance-wise', says Yu. You might not see a huge change beyond looking a little more defined, but you’ll feel a change in your overall strength and agility, she notes.

As for how to build this half a kilo of muscle (and then some!), Ritchey uses the R.E.P.S. framework below.

1. Repetitions

Pick a weight that allows you to approach muscular failure (not being able to do another rep) in six to 30 reps or fewer each set. Most people do between eight and 10 reps per set for muscle growth. Anything beyond 30 just won’t do that much to build muscle, Ritchey says.

2. Exercise selection

Pick simple exercises that target one muscle at a time like a biceps curl, says Ritchey. If you’re working multiple muscles at once, it might keep you from reaching muscular failure. Ritchey recommends doing three to four sets per exercise each workout to make sure you're working your muscles properly.

3. Protein

Protein is the building block for your muscles. Eating enough—about 1.2 grams per kilogram of bodyweight—is vital for their growth.

4. Structure

Ritchey suggests working each major muscle group one to two times per week on non-consecutive days. Why? It gives your muscles time to rest.

You can also accomplish this goal using bodyweight exercises. It’s really about making sure you’re doing exercises that get you within failure by 30 reps, says Ritchey. And, there are plenty of bodyweight exercises that could get you to failure by then, like push-ups, triceps dips, or planks. As you get stronger, you’ll also want to increase the resistance, play with rep count, or time under tension to keep challenging your growing muscles. (This is called progressive overload.)