Guides › Weight training
Weight trainingHow to bulk
Your surplus, protein and weekly weight gain, worked out. · 5 min read · Updated October 16, 2026
How we made this guide: we built it from the research below and checked every number against it: Iraki et al., off-season nutrition review (2019); Morton et al., protein meta-analysis (2018); Schoenfeld & Aragon, protein per meal (2018); Shcherbina et al., wrist-worn device accuracy (2017); Fernández-Elías et al., muscle water and glycogen (2015); Schumann et al., concurrent training meta-analysis (2022).
This guide is for lifters and hybrid athletes (runners, HYROX athletes, climbers who lift) who want to add muscle on purpose. “Eat more” is the usual advice, and it’s an easy way to gain more fat than you need. The research gives a rate to aim for, and that rate tells you how much to eat.
Maintenance is the number of calories that keeps your weight steady. A surplus is what you eat above it. Bulking is a small surplus, on purpose, while you train.
Step 1: Find your maintenance
The simplest reliable way needs no formula. Eat about the same amount every day for two weeks and weigh yourself each morning. If your weekly average didn’t move, that intake is your maintenance.
Your watch can’t do this for you. In a test of seven wrist-worn devices, none estimated calorie burn within 20% of the lab measurement, even though heart rate was mostly accurate (Shcherbina et al., 2017). Treat “calories burned” as a rough guide, not a number to eat back exactly.
Step 2: Pick your surplus
A review of off-season nutrition for bodybuilders recommends about 10–20% above maintenance for novice and intermediate lifters, and a more conservative 5–10% for advanced lifters (Iraki et al., 2019). For a 165 lb (75 kg) athlete with a maintenance of 2,800 kcal:
| Training experience | Surplus | Daily calories |
|---|---|---|
| Newer to lifting | +10–20% | 3,080–3,360 kcal |
| Advanced | +5–10% | 2,940–3,080 kcal |
If you also run, ride or do HYROX, we’d start at the low end of your range. You have hard sessions to fuel and recover from, and a smaller surplus is easier to adjust.
Step 3: Set protein first
A meta-analysis of 49 protein-supplementation trials found that protein above about 1.6 g per kg of body weight a day didn’t add more lean mass on average, with a plausible upper end around 2.2 g/kg (Morton et al., 2018). For a 75 kg athlete, that’s 120–165 g a day. Spread it as about 0.4–0.55 g/kg per meal over at least four meals (Schoenfeld & Aragon, 2018; Iraki et al., 2019), roughly 30–40 g a meal for the same athlete. Fill the rest with carbohydrate and fat; carbohydrate matters more on days with long or hard sessions.
How fast should you gain?
The same review recommends gaining about 0.25–0.5% of body weight a week for novice and intermediate lifters, and about 0.25% for advanced lifters (Iraki et al., 2019).
| Body weight | 0.25% a week | 0.5% a week |
|---|---|---|
| 130 lb (59 kg) | 0.33 lb | 0.65 lb |
| 150 lb (68 kg) | 0.38 lb | 0.75 lb |
| 170 lb (77 kg) | 0.43 lb | 0.85 lb |
| 190 lb (86 kg) | 0.48 lb | 0.95 lb |
| 210 lb (95 kg) | 0.53 lb | 1.05 lb |
Calculated from the rates above.
Faster isn’t better. The review warns that an aggressive surplus can add body fat you didn’t need; in one trial it describes, the group on the bigger surplus gained 1.1 kg of fat versus 0.2 kg in the other group (Iraki et al., 2019).
Read the scale without the noise
Your weight moves day to day for reasons that have nothing to do with muscle or fat. Stored carbohydrate (glycogen) is a big one: each gram stored in muscle is held with at least 3 grams of water (Fernández-Elías et al., 2015). A high-carb day, a salty dinner or a hard session can move the scale more than a week of real gain.
So look at average weekly weight changes from daily weigh-ins, as the review recommends (Iraki et al., 2019):
- Weigh yourself every morning under the same conditions: after the bathroom, before food or water.
- Average each week’s weigh-ins.
- Compare this week’s average with last week’s. That difference is your real rate of gain.
Adjust in small steps
Give a new intake two weeks before you judge it, then compare your weekly averages with your target rate. A simple rule we suggest (ours, not a finding from the studies):
| Two-week result | What to do |
|---|---|
| Gaining less than half your target | Add about 150–200 kcal a day, then wait two more weeks |
| Gaining more than 0.5% of your body weight a week (0.25% if you’re advanced) | Take off about 150–200 kcal a day |
| Anywhere in between | Change nothing |
Example: a 75 kg athlete targets 0.25% a week, about 0.19 kg. Their week-1 average is 75.0 kg and their week-3 average is 75.1 kg: 0.1 kg in two weeks, against a target of about 0.38 kg. That’s less than half, so they add about 200 kcal a day and check again in two weeks.
Before you add food, rule out water: a run of hard sessions, poor sleep or a salty week can hide real change for a week or two.
Muscle or fat? Two checks
- Waist: measure at your navel once a week, same time of day. If it climbs quickly while your weight rises slowly, more of the gain may be fat.
- Strength: muscle gain usually shows up as more reps or more load on your main lifts over a few weeks. If your waist grows and your lifts stall for three weeks or more, we’d trim 100–200 kcal a day.
When to stop
Decide your limit before you start: you reach your target weight, your waist grows by an amount you chose (say 2–3 cm, about an inch), or you reach a set number of weeks (for example, 12–16). These are personal guardrails, not research cutoffs.
Bulking around races
Running alongside lifting doesn’t seem to blunt muscle growth on average, although studies disagree a little (Schumann et al., 2022). Racing well is a different goal from gaining weight, though. A pattern we’d suggest: build in your off-season, return to maintenance for the final weeks before a race so you can focus on quality sessions, and pick the surplus back up afterward.
Know your real numbers
A bulk only works if you know roughly what you eat and how your weekly average moves, and that’s the hard part: logging every meal can feel like a second job. We built My Track Record so logging a meal, or your morning weigh-in, is one spoken sentence, and we estimate the calories and protein for you.
Get My Track Record on the App Store
By Andrew, founder of My Track Record. Andrew has been active all of his life across a variety of sports and continues to stay active through climbing, swimming, weight training, golfing, snowboarding, and more. He built My Track Record so logging food and training takes one spoken sentence and can support any activity. He puts these guides together from published sports science research cited on each page. About AndrewSources
- Iraki J, Fitschen P, Espinar S, Helms E. Nutrition recommendations for bodybuilders in the off-season: a narrative review. Sports (Basel). 2019;7(7):154. Source
- Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376–384. Source
- Schoenfeld BJ, Aragon AA. How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution. J Int Soc Sports Nutr. 2018;15:10. Source
- Shcherbina A, et al. Accuracy in wrist-worn, sensor-based measurements of heart rate and energy expenditure in a diverse cohort. J Pers Med. 2017;7(2):3. Source
- Fernández-Elías VE, Ortega JF, Nelson RK, Mora-Rodriguez R. Relationship between muscle water and glycogen recovery after prolonged exercise in the heat in humans. Eur J Appl Physiol. 2015;115(9):1919–1926. Source
- Schumann M, et al. Compatibility of concurrent aerobic and strength training for skeletal muscle size and function: an updated systematic review and meta-analysis. Sports Med. 2022;52(3):601–612. Source
General information for healthy adult lifters, not medical advice. If you have a medical condition, are pregnant, or have a history of disordered eating, talk to a doctor or registered dietitian before changing how you eat.