What’s the Difference Between Bulking and Cutting?

Building muscle and losing body fat aren’t always achieved in the same way. Depending on your goals, you may need to eat more, eat less or alternate between the two.

That’s where bulking and cutting come in. These nutrition and training strategies can help shape your physique, improve strength, build endurance and support long-term fitness goals.

Exercise physiologist Christopher Travers, MS, explains how bulking and cutting work and how to decide which approach is right for you.

Bulking vs. cutting

Bulking and cutting are two intentional phases of body recomposition. Each involves changing your diet and training to impact muscle development.

“If you’re someone who does wrestling, weightlifting or strength training on a regular basis, bulking and cutting is probably part of your process,” notes Travers. “These phases can have a direct impact on your strength, endurance and muscle definition.”

Let’s look more closely at both.

What is bulking?

A bulk involves eating more calories than your body burns each day. During this phase, you continue strength training while increasing your intake of protein, carbs and healthy fats to help build muscle.

Over time, these muscle gains can help you lift heavier weights and tackle more challenging workouts.

What’s the goal?

With bulking, you’re not trying to gain as much weight as possible in a short amount of time. Instead, you’re eating a modest amount of additional calories to support a steady increase in muscle size and strength. Think of it as building the foundation you’ll refine later during a cutting phase, when you focus on reducing body fat to reveal more muscle definition.

For athletes, it’s common to bulk up during the off-season or in the weeks leading up to a competition.

“While wrestlers and other athletes may use bulking to build muscle mass and improve performance, anyone can use this approach to support long-term strength and fitness goals,” says Travers.

Bulking diet

You could eat fried foods, processed foods and a boatload of desserts — what people call “dirty bulking” — to gain weight. But that’s not ideal or the safest route to success.

“The problem with dirty bulking is you could be adding a lot more fat mass, which in turn, could make your cut a lot harder,” cautions Travers. “So, you want to focus on increasing high-quality calories instead of just rapid weight gain.”

How many calories you need to add during a bulk varies from person to person. But in most cases, you’re looking at adding a calorie surplus of 200 to 500 calories a day.

Travers recommends eating more of these foods to fuel your fitness during a bulk:

• Complex carbohydrates, like fruits, whole-grain pastas, starchy vegetables and leafy greens
• Lean proteins, like chicken, turkey, tuna and tofu
• Healthy fats, like avocado, eggs, nuts, olives and olive oil

“Carbs help fuel performance, protein supports muscle growth and healthy fats support hormone health,” he continues. “You don’t have to add a whole extra meal. Just add a little bit more of these foods throughout the day to get your calorie count up.”

Not sure where to start? Work with a sports medicine physician or dietitian to put together a nutritional plan. They can also help you figure out how many calories you need for healthy weight gain.

Training while bulking

Weightlifting is crucial to bulking. Without it, you just pack on the pounds. But if you progressively increase your lifting sets, reps and weight, your body will put the extra calories you consumed to work.

“During a bulk, you’re trying to keep your intensity level high,” says Travers. “If you increase your resistance, you’re going to gain more lean muscle mass, which in turn, is going to help you burn more calories.”

How long do you bulk?

Bulking doesn’t happen overnight. It’s usually a months-long process of gradually increasing your calorie intake and training intensity.

“Bulking can last four to eight months, especially for people who are doing it for the first time,” says Travers.

What is cutting?

Cutting is the opposite of bulking. Instead of increasing calories, you eat fewer calories than your body burns during a single day. This temporary calorie deficit is meant to help you lose any fat you gained during the bulk phase, while also maintaining muscle mass.

Strength training remains important during the cutting phase. But you may not be able to lift as much weight or exercise for as long as you did during a bulk. That’s because of a decrease in energy from eating fewer calories.

What’s the goal?

“The goal of cutting is slow, sustainable fat loss — not rapid weight loss,” explains Travers. “When you’re cutting, you’re trying to minimize the loss of muscle mass.”

The goal of cutting is to:

• Lose body fat after a bulking phase.
• Make muscles more visible and defined.
• Improve how clothes fit or how your body looks.
• Achieve a specific physique or fitness goal.

Weightlifters, for example, may cut weight to compete in a specific weight class. Bodybuilders might cut before a competition to improve muscle definition.

Cutting diet

With cutting, you’ll want to focus on eating high-protein foods and high-fiber foods. Carbs should be limited.

“The problem with carbs is that you get a good energy rush out of them, but then you’re hungry an hour or two later,” warns Travers. “High-fiber and high-protein foods will help you manage that hunger while still fueling your workouts.”

Just be careful not to slash your calories overnight. Instead, reduce your intake gradually until you reach your target calorie deficit. This can help prevent excessive hunger, low energy levels and muscle loss.

Calorie deficits will vary, but it’s common to aim for 250 to 500 fewer calories than what you normally consume. If you’re not sure how much to cut, talk with a sports medicine professional or a dietitian.

Training during cutting

Strength training will help you keep muscle you’ve gained during the bulking phase. Try to stick to the same level of intensity. But you may also want to work in a couple of quick cardio exercises to increase calorie burn.

“If you’re feeling fatigued, you can cut back on sets or reps while lifting,” advises Travers. “You may also need longer recovery times between workouts, and that’s OK. Your body needs that extra time to recover when you’re fueling it with fewer calories.”

How long is cutting?

Cutting phases tend to run shorter than bulking. Travers says they can last anywhere from roughly six weeks to about four months.

“You don’t want to do too long of a cut or cut out too many calories from your diet because it can have unnecessary side effects,” he states. “Too much calorie deficit can lead to fatigue, poor recovery and sleep, and loss of muscle mass.”

Should you bulk or cut?

How you decide when to bulk or cut depends on your goals, current fitness level and overall health.

If you’re looking to lose body fat while maintaining muscle, cutting may be the way to go. But if your goal is to gain muscle and increase strength, bulking may be the better option.

It’s common to alternate between these two phases as goals and physical activities change, too. You may want to move from bulking to cutting (or the other way around) if you:

• Reach your target muscle size, strength and physique
• Gain more body fat than intended during a bulk
• Lose more weight or muscle than intended during a cut
• Don’t see desired results

Maintenance is also an option — you don’t have to constantly work to change your body. If you’re just getting started with a workout program, it might even be best to focus on eating healthy and exercising regularly. Devote a few months to locking down that routine before trying a bulk or cut.

“Bulking and cutting have to be planned and gradual,” clarifies Travers. “They can’t be rushed or too extreme because then you could increase your risk of injury and other complications.”