Bulking involves consuming excess calories to build muscle. Bodybuilders commonly use bulking as a way to increase their muscle mass before competitions.

Below, we explore bulking, and how to do it safely, in detail. We also review the risks.

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Bulking refers to the muscle-building phase of a traditional bodybuilding routine. It involves creating a calorie surplus to support muscle growth.

There are two main phases of the bodybuilding cycle: bulking and cutting.

During a bulking phase, bodybuilders typically consume additional carbohydrates and protein to maintain a calorie surplus.

The goal is to use these additional calories to build muscle. A person must strength train during a bulking phase to stimulate muscle growth. Bulking increases muscle mass and body fat.

Cutting involves entering a calorie deficit to lose any additional body fat from the bulking phase. Strength training is also essential during the cutting phase to minimize muscle loss.

Some people also include a maintenance phase in their bodybuilding cycle. This involves consuming enough calories to maintain the same body composition.

The goal of a bulking phase is to consume more calories than the body needs to maintain its current size.

Increase calorie consumption

The number of calories someone needs depends on various factors, including age, sex, and physical activity levels.

For example, a physically active man aged 18–30 requires at least 2,400 calories per day.

There is not enough research on bulking to determine the number of additional calories to aim for, and this may just vary from person to person.

Genetic factors that influence metabolism will also help determine a person’s target number of daily calories.

However, one 2015 review of the scientific literature found that male competitive bodybuilders typically consume 2,390–5,736 calories per day.

Consider increasing carb and protein intake

There is a lack of evidence about the most beneficial type of diet during a bulking phase. However, increasing carbohydrate and protein intake is a common strategy.

A 2014 review found that increasing protein intake may be beneficial. It concluded that consuming more than 2.2 grams (g) of protein per kilogram (kg) of body weight per day could improve body composition.

Decreasing fat intake may help

Some bodybuilders reduce fat intake during the bulking phase.

The results of a 2019 study suggest that successful bodybuilders tend to consume around 0.6 g of fat per kg — or 1.3 g per pound — of body weight per day.

The goal of bulking is to maintain a calorie surplus in order to build muscle. However, it is still essential to maintain a healthful diet.

Some people may be tempted to increase calorie intake with highly processed foods and snacks, but an unhealthful diet has the same consequences during bulking as at any other time.

People who bulk may develop poor nutritional habits, which can increase the risk of health problems over time.

Specifically, poor nutrition increases the risk of:

Also, bulking typically leads to an increase in body fat. Noticing this may cause a person to stop bulking before they see the benefits.

In some cases, people find it hard to move from a bulking to a cutting phase. Because bulking increases the appetite, switching to a calorie-restricted diet may be uncomfortable.

A bulking phase may help a person increase their muscle mass.

People new to strength training rarely require bulking to build muscle, as they typically build muscle quickly.

However, more experienced bodybuilders require additional calories to achieve this effect.

A person should eat a typical, healthful diet while bulking.

Still, during the bulking phase, people tend to consume more carbohydrates. Healthful carbohydrates include:

Healthful sources of protein include:

Some people also take supplements while bodybuilding. For example, protein powder provides one way to increase daily protein intake with fewer calories.

Caffeine and creatine are other supplements that may improve muscle performance. These are also ergogenic, meaning that they enhance energy production.

Avoid foods that provide more calories but little nutrition. Consuming large amounts of these foods will increase excess body fat during bulking and may even interfere with performance.

Try to avoid:

  • added sugar
  • highly processed foods, such as french fries
  • alcohol
  • sugary drinks

Bulking is a phase in the bodybuilding cycle that involves consuming excess calories to build muscle. People tend to consume additional protein and carbohydrates in this phase.

Afterward, a person tends to enter a cutting phase to burn the excess fat that builds up during a bulk.

During bulking, avoid foods that are high in calories but provide little nutrition, because these foods can still have negative health consequences — and may interfere with training.