How do I build muscle?

Lift with steady progress, eat a little more than you use, and get about 1.6 g of protein per kg of body weight a day. Train each muscle group at least twice a week, with sets that feel hard by the last few reps, and add weight or reps as they get easier. Muscle comes slowly, so a small surplus held for months works better than a big one.

How should I train?

Three things decide most of the result.

How often. A review of ten studies found that training a muscle twice a week grew it more than once a week, with the same total work. The WHO recommends strength work on two or more days a week for every adult.
How much. In a review of 15 studies, more weekly sets per muscle went with more growth, in a steady dose-response. Start with a few hard sets per muscle and add sets as your recovery allows.
How heavy. In a review of 21 studies, light loads (60% of your one-rep maximum or less) and heavy loads grew muscle about equally when the sets were hard. Heavy loads built more strength. So a wide range of reps works for size, as long as the set is hard.

Then make it harder over time. The American College of Sports Medicine’s rule: once you can do one or two reps more than your target, add a little weight next time, about 2 to 10%. Its 2026 review found that training to momentary muscle fatigue did not consistently change results, so finishing a set with a rep or two left is enough. New to the gym? See where to start.

In Nume: workouts are written for the days you can train, at home or at a gym, 15 to 60 minutes, with sets, reps and rest you follow step by step. After a full session that felt easy, the next similar one adds a little load or one or two reps. After a hard one, it stays the same. Tell Talk “focus on upper body” or “more leg work” and Nume keeps that in mind for the workouts it writes next.

How much should I eat?

More than you use, by a little. Nobody has pinned down the ideal surplus: a 2019 review in Frontiers in Nutrition found that the “sweet spot” for gaining muscle with the least fat has never been confirmed in a controlled trial. A 2019 review of off-season nutrition for natural bodybuilders suggests about 10 to 20% over maintenance for novice and intermediate lifters, aiming to gain about 0.25 to 0.5% of body weight a week, and about 5 to 10% for advanced lifters. For someone at 70 kg, that is about 0.2 to 0.35 kg a week.

Past a point, the extra food goes to fat. In a trial of elite athletes doing four strength sessions a week for 8 to 12 weeks, one group ate to a meal plan with a surplus, about 600 kcal a day more than a group that ate freely. The surplus group gained more weight (3.9% against 1.5%) and much more fat (fat mass up 15% against 3%). Their muscle gain was no greater.

Work out your maintenance with the calorie calculator.

In Nume: Build muscle plans your day 5% over maintenance, in a range from maintenance to 10% over. That is below the outside range above, so more of what you gain is muscle and less is fat. Profile > Goal shows it: “plus 5% to build muscle”. Your daily energy follows your latest weigh-in, so the plan grows with you. If you or a coach want a bigger surplus, set your own daily number and Nume plans 5% either side of it.

How much protein?

About 1.6 g per kg a day. A review of 49 trials with 1,863 adults doing resistance training found that, with protein supplements alongside lifting, muscle gains levelled off at about that intake, though the range of uncertainty ran up to about 2.2. The bodybuilding guidance above gives 1.6 to 2.2 g per kg, spread over three to six meals. At 70 kg, 1.6 g per kg is about 112 g a day. See how to get enough from food you already eat, or work out your own range with the protein calculator.

In Nume: with two or more sessions a week, your protein is set at 1.6 g per kg (range 1.4 to 1.8). It builds up about 12 g a week from what you eat now, so it stays reachable, and if you’ve trained steadily for three months or more you get the full amount from the start. Every meal shows its protein, at your own eating times. A daily scoop of whey you set up as a regular item counts toward the day.

Do I need supplements?

No, though two can help. Whey is a handy way to reach your protein. Creatine monohydrate, at 3 to 5 g a day, is the supplement the International Society of Sports Nutrition rates most effective for lean mass and hard training. See whether you need whey or creatine.

In Nume: add “creatine 5 g at 8 am” and it sits on your day at that time, in your words, with a reminder if you want one.

How fast does muscle come?

Slowly, and fastest while lifting is new to you. How long you have trained directly affects how fast you gain, so the early months bring the most. At a gain of 0.25 to 0.5% of your weight a week, a 70 kg lifter puts on about 0.75 to 1.5 kg a month, and not all of it is muscle. Your lifts usually show progress before the mirror does.

If you’re new to lifting and carrying some fat, you may not need a surplus at all: see losing fat and building muscle together.

How do I know it’s working?

Your lifts. Weights or reps going up across weeks on the same exercises.
Your weight. Trending up slowly, at about the pace above, read over two or three weeks.
Your sets. Each muscle group getting hard work at least twice a week.
Photos. Same light, same pose, every few weeks.

In Nume: for Build muscle, Progress leads with your strength and your protein. Progress > Strength shows your best set for each lift, and your sets a week by movement group: push, pull, squat, hinge, lunge, core and carry. Your weight is compared with a weigh-in at least 14 days earlier, and you can add up to four private photos to a weigh-in. Only you see them, and they are never read by AI.

What about tired days and time away?

Gains come from months of steady weeks, so the weeks that go wrong matter as much as the good ones.

In Nume: before a workout, Today asks whether you’re good to go, a bit tired or sore, and “A bit tired” makes that session lighter. A skipped session is dropped, so nothing piles onto the next one. The first session after time away comes back a little lighter, so it feels good, and your record keeps every lift’s last working weight. See getting back on track.

Building muscle with Nume

Choose Build muscle and Nume runs the long part. Your day is planned a little over maintenance and follows each weigh-in. Your protein is set for training and builds up week by week. Workouts are written for your days, at home or at a gym, and step up when a session felt easy. Meals come from the dishes you already eat, at your own one to six eating times, with protein on each. Progress shows your strength first: your bests by lift and your sets by movement group, beside your weight and protein. See choosing a goal if you’re between goals, or how Nume works across a day.

Common questions

Can I build muscle at home?

Yes. Light loads grow muscle about as well as heavy ones when the sets are hard, so bodyweight and band exercises work when they get harder over time: more reps, slower lowering, harder versions. Nume writes home workouts as well as gym ones.

Do I need to bulk?

You need a small surplus, not a large one. In the athlete trial above, the larger surplus added fat without adding muscle.

How many days a week should I lift?

Two to four, so each muscle gets worked at least twice a week. Three full-body sessions, or four split between upper and lower body, both do it.

Should I still do cardio?

Yes, if you enjoy it or play a sport. The WHO recommends 150 to 300 minutes of moderate activity a week alongside strength work. In Nume, your walks, runs and sport count in your daily energy, and food is planned around them.

Checked on 12 November 2026 · The Nume team