Do You Need to Bulk to Build Muscle?

If you have spent much time around bodybuilding or strength training, you have probably heard some version of the same advice:

If you want to build muscle, you need to eat more.

Usually, that means intentionally creating a calorie surplus, increasing carbohydrates, watching the scale climb, and accepting some fat gain along the way. Then, once the muscle building phase is over, you diet the extra fat back off.

The logic makes sense. Building new tissue requires energy, so more calories should theoretically create a better environment for muscle growth.

But how much extra energy do you actually need?

A new 2026 study published in Nutrients tested that question in experienced lifters. Researchers increased calorie and carbohydrate intake while keeping protein intake and resistance training similar.

The extra calories did not produce significantly more muscle, strength, or muscular endurance. Bulking for muscle gain

That doesn't mean calorie intake doesn't matter.

It does suggest that the traditional idea of eating substantially more simply because you're trying to build muscle deserves another look.

TLDR: More Calories Didn't Produce More Muscle

This study compared a protein supplement with the same protein supplement plus additional carbohydrate in experienced male lifters. The added carbohydrates successfully increased calorie intake, but they didn't significantly improve the training adaptations researchers measured.

• 20 resistance trained men completed the study, averaging nearly 10 years of lifting experience.
• Each participant completed both an 8 week protein only condition and an 8 week higher carbohydrate condition.
• Both supplements provided 30 grams of protein, but the higher carbohydrate supplement provided an additional 50 grams of carbohydrate.
• Actual reported carbohydrate intake differed by approximately 33 grams per day between conditions.
• Reported energy intake was approximately 485 calories per day higher during the carbohydrate condition.
• Protein intake was essentially identical at 178 versus 173 grams per day.
• Training volume was also nearly identical.
• The additional carbohydrate and calories produced no statistically significant improvement in lean mass, measured muscle size, squat strength, knee extension strength, or muscular endurance.
• The study does not prove that calorie surpluses are useless. It suggests that once energy and protein needs are being met, simply eating more may not automatically produce more muscle.
• These findings should not be extrapolated to people who are dieting, eating very little carbohydrate, or performing extremely high volume glycogen depleting training.

Bulking for muscle gain

The Traditional Argument for Bulking Makes Sense

There is a legitimate physiological reason people believe a calorie surplus helps build muscle.

Muscle protein synthesis requires energy.

If you're chronically under eating, the body has fewer resources available for building new tissue. Energy deficiency can reduce anabolic signaling and muscle protein synthesis, and previous research has found that calorie restriction can impair gains in fat free mass during resistance training. Bulking for muscle gain

So we know one side of the equation pretty well.

Not eating enough can make gaining muscle harder.

The mistake may be assuming the opposite is equally true.

If too few calories are bad for muscle growth, it seems logical that increasingly larger calorie surpluses should produce increasingly more muscle.

Human physiology doesn't necessarily work that way.

Building Muscle Doesn't Require As Much Energy As You Might Think

One point from this paper jumped out at me.

The researchers note that based on estimates of the energy contained in muscle tissue and the metabolic cost of creating it, building one kilogram of muscle per month may require less than 100 additional calories per day.

The body could theoretically obtain some of that energy from stored body fat, which raises a pretty obvious question:

Do you actually need a calorie surplus to maximize muscle growth? Bulking for muscle gain

We don't have a definitive answer.

But it helps explain why simply adding hundreds of calories per day doesn't necessarily translate into faster muscle growth.

Your body can't just funnel every extra calorie into your biceps.

Unfortunately, it has another very convenient storage location for those calories.

Body fat.

The Researchers Used Experienced Lifters

This wasn't a study involving people who had never touched a barbell.

Twenty resistance trained men completed the experiment.

Their average age was approximately 27 years, and they reported an average of 9.7 years of resistance training experience. They trained their upper body approximately three times per week and their lower body twice per week.

Their average squat one repetition maximum was approximately 1.9 times their body weight. Bulking for muscle gain

These were legitimately experienced lifters.

That's both a strength and a limitation.

Experienced lifters are exactly the population where small nutritional differences become interesting because they've already accumulated years of training adaptations.

But experienced lifters also gain muscle slowly.

Detecting meaningful differences over only eight weeks becomes difficult.

We'll come back to that.

Everyone Completed Both Diet Conditions

The researchers used a crossover design.

Participants first completed one eight week supplementation phase and then switched to the other condition for another eight weeks.

In the protein condition, they consumed a supplement providing:

30 grams protein, 4 grams carbohydrate, and 2 grams fat.

In the higher carbohydrate condition, they consumed:

30 grams protein, 54 grams carbohydrate, and 2 grams fat.

The extra carbohydrate came from maltodextrin.

Participants continued their normal diets and resistance training programs throughout the study. On training days, they consumed the supplement within one hour after their workout. Bulking for muscle gain

This design is useful because each participant essentially served as his own comparison.

Instead of comparing one group of genetically gifted muscle building machines with another group of people who struggle to gain anything, researchers could examine what happened to the same person under both nutritional conditions.

They Actually Ate More Calories

This is important because nutrition studies frequently tell people to eat differently without participants actually doing it.

Here, there was a measurable difference.

During the higher carbohydrate condition, reported intake averaged:

2,751 calories per day

compared with

2,266 calories per day during the protein only condition.

That's a reported difference of 485 calories per day.

Carbohydrate intake averaged 248 versus 215 grams per day, a difference of 33 grams.

Protein intake was essentially identical at 178 versus 173 grams per day, and fat intake wasn't significantly different either. Bulking for muscle gain

So the researchers successfully created the basic situation they wanted.

Same lifters.

Similar training.

Similar protein.

More carbohydrates and more reported calories.

Did it build more muscle?

Not significantly.

More Calories Didn't Produce More Measured Muscle Growth

Researchers measured muscle growth several different ways.

They used DXA to assess lean mass.

They used ultrasound to measure elbow flexor and thigh muscle thickness.

They measured the cross sectional area of the vastus lateralis.

Across those measurements, none showed a statistically significant advantage from the higher carbohydrate and calorie condition. Bulking for muscle gain

Vastus lateralis cross sectional area increased by approximately 1.82 cm² during the protein condition and 1.36 cm² during the higher carbohydrate condition.

Lean mass changed by approximately minus 0.20 kg during the protein condition and plus 0.55 kg during the higher carbohydrate condition.

That lean mass difference might look interesting at first glance, but the confidence interval was wide and crossed zero. It wasn't statistically significant.

More importantly, researchers didn't see a consistent pattern across the direct muscle size measurements suggesting that the extra calories were producing more actual muscle tissue. Bulking for muscle gain

That distinction matters.

A change in DXA lean mass isn't automatically the same thing as newly built contractile muscle.

Strength Didn't Improve More Either

Maybe extra carbohydrates didn't noticeably increase muscle size, but perhaps they improved training enough to produce greater strength gains.

That didn't happen either.

Squat one repetition maximum increased approximately:

5.24 kg during the protein condition

and

6.77 kg during the higher carbohydrate condition.

The difference wasn't statistically significant.

Knee extension peak torque also didn't improve more with additional carbohydrate. Bulking for muscle gain

There was a nonsignificant trend toward better fatigue resistance during the higher carbohydrate condition, but it didn't reach statistical significance and wasn't accompanied by greater training volume. Bulking for muscle gain

So across hypertrophy, strength, and muscular endurance, researchers couldn't identify a convincing benefit from simply adding the extra carbohydrate and energy.

Why Didn't More Carbohydrate Improve Training?

Carbohydrates matter for exercise.

I'm certainly not arguing otherwise.

The question is whether typical resistance training depletes enough muscle glycogen for more carbohydrate to become the limiting factor.

Often, it probably doesn't.

The paper notes that conventional resistance training sessions generally reduce muscle glycogen by 40% or less. That's usually well above the critically low glycogen levels associated with impaired neuromuscular function. Bulking for muscle gain

Previous research has also found that carbohydrate supplementation doesn't reliably improve resistance training performance when people are already fed and performing moderate training volumes.

That changes the question.

Instead of asking whether carbohydrates are important, ask whether additional carbohydrates improve training when glycogen availability is already adequate.

Those aren't the same question.

If adding carbohydrates doesn't let you train harder, perform more quality repetitions, or accumulate more productive training volume, there isn't an obvious reason to expect those carbohydrates to suddenly create more muscle.

As the authors point out, mechanical tension remains the primary stimulus for hypertrophy. Bulking for muscle gain

You can't out carbohydrate the training stimulus.

This Doesn't Mean Low Carb Is Better for Building Muscle

This is where studies like this get butchered on social media.

The conclusion is not:

"Carbs don't matter for muscle growth."

The participants weren't following ketogenic diets.

Even during the lower carbohydrate condition, average intake was approximately 215 grams per day.

During the higher carbohydrate condition, it was approximately 248 grams per day. Bulking for muscle gain

This study compared moderate carbohydrate intake with somewhat higher carbohydrate intake.

That's very different from comparing adequate carbohydrate availability with severe carbohydrate restriction.

Athletes doing substantially more training, multiple daily sessions, endurance work combined with lifting, or very high volume resistance training may have considerably greater glycogen requirements.

The authors explicitly warn against extrapolating these findings to athletes performing more glycogen depleting exercise. Bulking for muscle gain

Context matters.

It Also Doesn't Mean Calories Don't Matter

Energy availability absolutely matters.

If you're in a substantial calorie deficit, your body is operating in a different physiological environment.

A previous meta analysis cited by the researchers found that energy deficiency impaired resistance training induced gains in fat free mass, although strength gains weren't significantly affected. Bulking for muscle gain

So I wouldn't take this study and tell someone eating 1,600 calories per day while trying to gain muscle that they shouldn't increase their food intake.

That's not what was tested.

The better interpretation is:

Once you're eating enough to support training and recovery, adding increasingly more calories may provide diminishing returns for muscle growth.

At some point, those extra calories have to go somewhere.

And muscle growth has a speed limit.

The Dirty Bulk Makes Even Less Sense

This is where I think the study has the most practical value.

The old school "dirty bulk" strategy essentially assumes that if a modest calorie surplus is good, a large one must be better.

Eat everything.

Gain weight quickly.

Get as big as possible.

Diet later.

The problem is that muscle growth can't simply accelerate indefinitely because more energy is available.

Previous research discussed in this paper has found that higher energy intakes frequently increase body weight and fat gain without producing significantly greater resistance training adaptations. Bulking for muscle gain

That's a terrible trade if the extra body weight is primarily fat.

You eventually have to diet that fat off.

That means spending more time in an energy deficit, which is exactly the environment where maintaining or gaining muscle becomes harder.

Eating enough to support growth makes sense.

Eating substantially beyond what your body can actually use for muscle growth mostly makes the next diet longer.

The Scale Is a Terrible Muscle Meter

One reason bulking became so popular is that it's psychologically satisfying.

You eat more.

Your body weight increases.

Your gym performance often improves.

You look bigger.

It feels like the bulk is working.

Some of that increased weight may absolutely be muscle.

But some is glycogen.

Some is water.

Some is additional food sitting in the gastrointestinal tract.

And some is body fat.

The faster body weight increases, the less confident we should be that most of that gain represents new contractile muscle.

This study is another reminder that weight gain and muscle gain aren't interchangeable terms.

If someone gains 15 pounds during a bulk, they didn't necessarily build 15 pounds of muscle.

Not even close.

Experienced Lifters Probably Need To Be Even More Patient

The participants in this study had nearly a decade of lifting experience.

That matters because muscle growth generally slows as training experience increases.

A beginner can build muscle relatively quickly.

An advanced lifter can't.

That means experienced athletes may have even less reason to aggressively increase calories.

If your physiological capacity to add new muscle is relatively slow, dramatically increasing calorie intake doesn't necessarily change that capacity.

It may simply increase the rate at which you gain body fat.

For an experienced lifter, a slow rate of weight gain may be a feature rather than a problem.

Muscle takes time.

Eating faster doesn't necessarily make it grow faster.

Protein Was Already High

Another reason the extra calories may not have helped is that these participants were already eating plenty of protein.

Average intake was approximately 173 to 178 grams per day, depending on the condition. Bulking for muscle gain

That matters because protein provides the amino acids needed to build muscle tissue.

If protein intake had been inadequate, adding calories through a protein rich food or supplement could have produced a very different result.

Here, protein was essentially matched.

The main nutritional difference was carbohydrate and energy intake.

That's one of the things I like about the study.

It helps separate the effects of more calories from the effects of more protein.

A high calorie diet that also dramatically increases protein isn't testing calories alone.

This study came closer to doing that.

But There's a Weird Issue With the Reported Calories

There's one detail in the paper worth discussing.

The reported difference in total calorie intake was 485 calories per day.

But based on the reported differences in protein, carbohydrate, and fat using standard calorie conversions, the macronutrient differences only accounted for approximately 251 calories per day.

The researchers acknowledge this discrepancy. Bulking for muscle gain

That doesn't mean the dietary data are useless.

It does highlight one of the biggest problems with nutrition research:

People are terrible at accurately reporting what they eat.

The researchers used four day food logs and had them reviewed by a registered dietitian, which is better than simply asking people what they remember eating.

But self reported nutrition data are still self reported nutrition data.

The actual energy difference between conditions is therefore somewhat uncertain.

Participants Also Compensated for Some of the Extra Carbohydrate

The supplement was designed to provide 50 additional grams of carbohydrate per day.

But based on the food logs, the actual difference in daily carbohydrate intake was only 33 grams.

That suggests participants may have unconsciously eaten slightly less carbohydrate elsewhere in their diets when given the carbohydrate supplement.

The authors specifically discuss this possibility. Bulking for muscle gain

That's actually pretty normal.

Human appetite and food intake aren't perfectly fixed.

Give someone extra calories and they may compensate by eating slightly less later.

It does, however, mean this study didn't create as large a carbohydrate contrast as researchers originally intended.

The Study Was Small

Only 20 men completed the study.

That's not a lot of people.

The crossover design improves statistical power because each participant experiences both conditions, reducing some of the enormous person to person variability in muscle growth.

But a small study still creates uncertainty.

The confidence intervals were wide enough that the researchers explicitly acknowledge they cannot rule out a small positive or negative effect from the additional carbohydrate and energy intake. Bulking for muscle gain

That's an important distinction.

"No statistically significant difference" doesn't prove the two diets are physiologically identical.

It means this experiment didn't detect a reliable difference.

Eight Weeks Isn't Very Long for Advanced Lifters

This may be an even bigger limitation.

Each condition lasted only eight weeks.

Remember, these guys had almost ten years of training experience.

Advanced lifters don't build muscle particularly quickly.

Trying to detect a small nutritional enhancement to muscle growth over eight weeks in highly trained athletes is difficult, even with good measurement techniques.

The authors acknowledge that the participants' training status and short study duration reduced the magnitude of adaptations they could reasonably expect to detect. Bulking for muscle gain

A six or twelve month study would be far more interesting.

It would also be much harder and more expensive to conduct.

The Crossover Design Is Both a Strength and a Weakness

Normally, I like crossover studies.

They're particularly useful in sports nutrition because the same person receives both treatments.

But muscle growth creates a problem.

You can't "wash out" eight weeks of new muscle and strength before switching conditions.

If someone gained muscle during the first phase, that adaptation carried into the second phase.

The researchers accounted statistically for treatment order and also performed an analysis using only the first intervention period. Those analyses reached similar conclusions.

Still, the authors correctly identify carryover as a significant design limitation. Bulking for muscle gain

So the crossover design increased statistical power while simultaneously introducing another source of uncertainty.

Science is fun like that.

What This Study Actually Tells Us About Bulking

I wouldn't use this paper to say:

"You don't need a calorie surplus to build muscle."

It didn't directly test maintenance calories against a precisely controlled surplus.

Food intake wasn't tightly controlled.

The actual calorie difference is uncertain.

And all participants were experienced male lifters.

But I do think it strengthens a more conservative position.

You probably don't need to force feed yourself to maximize muscle growth.

Get enough protein.

Eat enough total energy to support training and recovery.

Consume enough carbohydrate to maintain training quality.

Train hard.

Progress your training.

Sleep.

Then give the process time.

If body weight isn't increasing at all and muscle growth has stalled, increasing calories modestly makes sense.

What this study doesn't support is the assumption that continually increasing calories will continually increase muscle growth.

A Small Surplus Still Makes Practical Sense

There's an important difference between saying a calorie surplus is physiologically mandatory and saying it's practically useful.

Trying to perfectly match maintenance calories every day is nearly impossible.

Energy expenditure changes.

Training changes.

Activity changes.

Food labels aren't perfect.

Your appetite changes.

A small calorie surplus provides some insurance against accidentally spending too much time in an energy deficit, particularly for lean, active people trying to maximize muscle gain.

That's very different from deliberately eating 500, 800, or 1,000 calories above your needs because you're "bulking."

You don't need to turn muscle gain into an eating contest.

Carbohydrates Still Have an Important Role

I also don't want anyone reading this and deciding carbohydrates are pointless for lifters.

They aren't.

Carbohydrates help replenish glycogen and can support high intensity training, particularly as training volume increases.

For athletes combining endurance and resistance training, training multiple times per day, or performing long glycogen depleting sessions, carbohydrate requirements can become substantially higher.

This study simply suggests that more carbohydrate isn't automatically better when someone is already consuming enough to support conventional resistance training.

That's a much narrower and more useful conclusion.

The Bottom Line

A new 2026 study examined whether adding carbohydrate and calories would improve muscle growth and strength in experienced resistance trained men.

Participants consumed either 30 grams of protein alone or the same 30 grams of protein plus 50 grams of additional carbohydrate per day during separate eight week periods. Bulking for muscle gain

The higher carbohydrate condition increased reported energy intake by approximately 485 calories per day and carbohydrate intake by about 33 grams per day.

It didn't significantly increase muscle size.

It didn't significantly increase lean mass.

It didn't significantly improve squat strength.

And it didn't significantly improve muscular endurance. Bulking for muscle gain Bulking for muscle gain

That doesn't prove calorie surpluses are useless.

It certainly doesn't mean you should try to build muscle while chronically under eating.

But it adds to a growing argument that once you're consuming enough calories, protein, and carbohydrates to support training and recovery, simply eating more may not make muscle grow faster.

Muscle growth has limits.

Calories don't remove them.

So if you're trying to gain muscle, I'd focus less on "bulking" and more on eating enough, getting adequate protein, training progressively, and gaining weight slowly enough that most of what you're adding is actually useful tissue.

You can always eat more.

Getting rid of unnecessary body fat afterward is considerably less fun.

Reference

Henselmans M, Tiede DR, Plotkin DL, et al. Effects of Modest Carbohydrate Energy Supplementation on Resistance Training Adaptations in Trained Men: A Crossover Trial. Nutrients. 2026;18:1961. Published June 17, 2026. doi:10.3390/nu18121961.