How to Bulk
A bigger surplus does not build muscle faster. It builds the same muscle with more fat attached, and the study that showed this used elite athletes.
Last updated: 30 September 2026
Overview
A bulk is a deliberate period of eating more than you burn so that training produces more muscle than it otherwise would. It is not a licence, a season, or a personality.
The central mistake is treating the surplus as the active ingredient. It is not. Training is the signal; the surplus is permission. Doubling the permission does not double the signal.
Quick Answer
A lean bulk means eating roughly 10 to 20 percent above maintenance and gaining about 0.25 to 0.5 percent of body weight a week. Larger surpluses do not build muscle faster — in trained athletes they produce similar lean mass gains with noticeably more body fat.
Key Points
- Aim for around 0.25 to 0.5 percent of body weight a week.
- A surplus of roughly 10 to 20 percent above maintenance is enough.
- Extra calories beyond that become fat, not extra muscle.
- Beginners should sit at the faster end, experienced lifters the slower.
- Training and protein decide the outcome. The surplus just allows it.
The evidence against eating big
Garthe and colleagues took 39 elite athletes through a weight-gain phase with four extra strength sessions a week. One group received structured nutritional guidance; the other ate as they liked.
Both groups improved their one rep max by 6 to 12 percent. The guided group gained more body weight. And the paper's own conclusion is the part worth keeping: excess energy intake in a weight-gain protocol should be considered carefully, because of undesirable increases in body fat.
That is elite athletes, training hard, on a supervised programme. If a big surplus does not buy them extra muscle, it is not going to buy it for anyone reading this.
Rate of gain
The number to watch is the scale trend, not the calorie total.
| Training age | Weekly gain | For an 80kg lifter |
|---|---|---|
| First year | 0.4 to 0.5% | 320 to 400g |
| 1 to 3 years | 0.25 to 0.4% | 200 to 320g |
| Experienced | 0.2 to 0.25% | 160 to 200g |
The reason experienced lifters go slower is not restraint for its own sake. It is that their rate of muscle gain is genuinely lower — see how long it takes to build muscle — so a faster weight gain is, arithmetically, mostly fat.
Setting it up
1. Find maintenance. Track intake and weight for two weeks without changing anything. Whatever holds your weight steady is maintenance. The TDEE calculator gives you a starting estimate, not an answer.
2. Add 10 to 20 percent. For most people that is 250 to 500 calories.
3. Hit protein. Around 1.6 to 2.2g per kg. See the protein guide.
4. Put the rest in carbohydrates. They fuel the training that is doing the actual work.
5. Weigh yourself daily, average weekly. Judge the average against the table above.
6. Adjust by 100 to 200 calories if the average is off after two or three weeks.
Reading the scale honestly
Week to week, body weight is noisy: water, sodium, carbohydrate intake, training soreness and digestion all move it more than fat or muscle do. A single weigh-in tells you almost nothing.
| What you see | What it probably is |
|---|---|
| +1.5kg overnight | Food, water, salt |
| Flat for 5 days then a jump | Normal noise, keep going |
| Flat for 3 weeks | Genuinely not gaining, add calories |
| +1kg a week, consistently | Too fast, reduce calories |
How long to run it
Long enough to matter, short enough that you do not have a long diet ahead of you. Three to six months is a reasonable block, ended when body fat reaches a level you are no longer happy training at rather than on a date.
The alternative, for beginners and for anyone returning from a break, is body recomposition: gaining muscle while losing fat at roughly stable weight. It works in those two situations and rarely in others.
Common Mistakes
| Mistake | Why it causes problems | Better approach |
|---|---|---|
| A big surplus for faster gains | Same muscle, more fat | 10 to 20% above maintenance |
| Treating a bulk as unrestricted eating | Fat gain outpaces muscle by a long way | Track the weekly average |
| Bulking without a training plan | Calories do not build anything on their own | Programme first |
| Judging progress on daily weight | Far too noisy to read | Weekly averages |
| Bulking at 25 percent body fat | Insulin sensitivity and appearance both worsen | Diet first, then gain |
| Never ending it | A long bulk becomes a long diet | Three to six month blocks |
Frequently Asked Questions
How many calories should I eat to bulk?
Maintenance plus roughly 10 to 20 percent, which is usually 250 to 500 calories. Confirm it against your weekly weight trend rather than trusting the calculation.
How fast should I gain weight?
About 0.25 to 0.5 percent of body weight a week, faster in your first year and slower once you are experienced.
Is dirty bulking faster?
No. In trained athletes a larger surplus produced similar strength gains and more body fat. The extra calories are not converted into extra muscle.
Can I build muscle without bulking?
Beginners and returning lifters often can, at roughly stable weight. Experienced lifters in a deficit will find it slow at best.
Should I do cardio while bulking?
Yes, for health and work capacity. Keep the volume moderate so it does not eat the surplus. See cardio and muscle growth.
Sources
Garthe et al. (2013), effect of nutritional intervention on body composition and performance in elite athletes - https://pubmed.ncbi.nlm.nih.gov/23679146/
American College of Sports Medicine - https://acsm.org/
British Dietetic Association - https://www.bda.uk.com/