How Long Should I Bulk For?
Bodybuilding experts suggest that you should bulk for no less than 6 weeks, but you are more likely to see optimal gains in muscle mass if you bulk for a minimum of 8 weeks to one year. A typical bulking phase may last from 4-8 months. Unfortunately, however, there is very little clinical evidence to say definitively how long your bulking phase should last. In fact, many study authors point to the fact that bulking practices are often based on unsubstantiated gym myths rather than science-backed data.
Bulking and cutting are practices used by bodybuilders or other strength-trained athletes. The goal of bulking is to maximize muscle gain while minimizing gains in fat mass. A cutting phase generally follows the bulking phase to further reduce body fat, often prior to a competition or event. There are several factors you should consider when determining how long you should bulk for and how long your cutting phase should last, including your goals, your experience level and your training practices.
Key Takeaways in This Article:
Evidence-based guidelines for nutritional intake during bulking and cutting are limited. As a result, bodybuilders often rely on anecdotal recommendations from non-scientific sources (such as guidance from fellow lifters) to determine the best nutritional intake recommendations.
Calorie intake during bulking should increase to accommodate increases in training load and desired increases in muscle mass. Calorie intakes ranging from 3500 - 4000 calories or more have been observed.
Protein intake during bulking should be prioritized to facilitate muscle hypertrophy. A protein intake of 2.5 grams per kilogram of bodyweight per day (g/kg/d) is typical among bodybuilders. Higher protein intakes (up to 4.1 g/kg/d) have been observed with limited success. However, some researchers suggest consuming more than 1.6 g/kg/d is unnecessary.
Adequate carbohydrate intake is also essential to allow for the increased energy needed to train effectively during the bulking phase.
Non-nutrition factors such as genetics, training load, experience level, and supplement use play a significant role in the success of bulking and cutting.
How Long Should You Bulk For?
There is no strict guideline for the correct duration of a bulking phase. In fact, the best duration for you might be very different than the best duration for another athlete. Factors that can affect bulking phase duration include:
Experience: If you are new to bulking and cutting, you may want to experiment with a shorter bulking phase of 2-3 months at first. This will help you determine if you can maintain the diet and training load necessary to make significant muscle gains. A more experienced lifter can rely on their training history and stay in the bulking phase for a longer time, potentially up to a year, to maximize muscle hypertrophy.
Goals: If you have an event coming up, the amount of time before the event will help you determine how long you can stay in the bulking phase. You’ll want at least 1-3 weeks of cutting before a physique competition or any contest that requires you to be very lean and muscular.
Sustainability: Both the bulking and cutting phases can be hard to maintain simply because they require you to carefully track and manage your calorie and macro intake. For some people, the necessary dedication and consistency are too much to sustain for an extended period of time. In that case, shorter bulking and cutting phases (6-8 weeks of bulking) are more likely to be effective. If you are inconsistent with your training or nutritional intake during bulking, you are not likely to see significant results, and you may see unwanted gains in fat mass.
Individual response: Some people are able to gain muscle mass faster than others. In fact, studies show that genetics play a significant role in how fast you build muscle.(2) Someone who puts on lean muscle mass quickly can commit to a shorter bulking phase than someone who puts on muscle mass slowly.
Without clear evidence-based guidelines about how long to bulk you may be left wondering, how many months should I be bulking? These guidelines should give you an idea of what will work best for you.
Short-term bulking (6-8 weeks) is best for someone who is new to bulking and just wants to give it a try. It might also be a good time frame for an experienced lifter who knows they can put on muscle fast and has a competition in a few months.
Moderate-term bulking (2-6 months) is the best time frame for most athletes who know how their body responds to training and who knows that they can sustain a rigorous diet for several months. It would also be a good time frame for someone who plans to participate in a competition in 4-8 months.
Long-term bulking (6 months to one year) can be a smart plan for someone who is already fairly lean and very committed to their lifting program. For example, an athlete who has participated in other types of rigorous fitness training (such as marathon training) or an experienced bodybuilder may bulk for a longer period of time to gain significant muscle.
Calories for Bulking
You will need to create a calorie surplus in order to gain muscle mass during bulking. Extra calories are also needed to fuel intense workouts. The general recommendation is that you’ll want to increase your calorie intake by 300 to 500 calories per day during this phase. But there isn’t significant research to back up this number.
What the Science Says About Calories During Bulking
Researchers have evaluated calorie intakes during bulking.
In one study published in 2021, researchers observed that calorie intakes among experienced male bodybuilders averaged about 44 calories per kilogram of bodyweight per day during the bulking phase.(4) For a man who weighs 200 pounds (91 kilograms) that means he would consume just over 4000 calories per day during the bulking phase. A 175-pound man would consume about 3476 calories per day.
Another 2015 research review investigating typical dietary intakes of bodybuilders, found that the average calorie intake during bulking was 3,821 per day for men and 3,249 per day for women.(6)
A 2022 study evaluating the nutritional habits of amateur and professional bodybuilders found that typical calorie intakes average roughly 36 calories per kilogram of bodyweight per day in the UK but range from range 23 to 46 calories per kilogram of bodyweight per day in North and South America.(5)
How to Calculate Your Calories for Bulking
To determine the best calorie number for you, you need to evaluate your current caloric intake and consider the potential increase in training load during your bulking phase. There are various formulas you can use to estimate your basic calorie needs (such as the Mifflin-St. Jour equation for resting metabolic rate or RMR). But you’ll get a better idea of your specific needs by keeping a food journal for 5 days.
Follow these steps:
Download a tracking app, such as MyFitnessPal, to your smartphone or laptop.
Input every food and beverage that you consume for five days during a time when your training protocol and food intake are typical and your weight is stable. Take note of your total calorie intake for each day.
To calculate your average calorie intake, add the daily totals for five days, then divide by five. This is the number of calories you need to maintain your current weight.
To determine your caloric intake for bulking, start by adding 300 calories.
Track your progress using a smart scale that provides data about body composition and weight.
If you start to see an increase in muscle mass, stick with your current calorie intake. If not, increase your intake by 100 calories and repeat steps 5 and 6.
Keep in mind that increases in water weight are typical during bulking. Using a scale that measures water weight in addition to measuring fat-free mass will help you determine if you are gaining muscle or water.
If you don’t want to go through the steps for calculating your optimal caloric intake for bulking, you can simply use numbers referenced in research (roughly 3800 for men and 3500 for women) as a default. Just be aware that since those numbers are not personalized for you, it is possible that you will not see the results you desire.
Macros for Bulking
Macronutrient intake during bulking should focus on protein intake. Protein is essential for muscle hypertrophy. Also, studies have shown that increasing your protein load helps limit the amount of fat gained during the bulking phase.
What the Science Says About Macros During Bulking
So, how much protein do you need during bulking? Research has yielded mixed results regarding protein intake for bodybuilders.
Several studies have shown that athletes typically consume about 2.5 g/kg/d during bulking, with each meal containing 0.33 to 0.55 grams of protein per kilogram of body weight.(3, 4) It should be noted however, that this was a research observation, not a recommendation.
One study noted that muscle mass increases were not significant in bodybuilders who consumed over 2.6 and up to 3.3 g/kg/d of protein, suggesting there may be an upper limit to protein intake when muscle gains are the goal. (2)
In another research review, study authors noted that protein consumption over 1.62 g/kg/d "did not further enhance muscle mass gains from resistance training.” (4)
A cross-sectional study revealed that successful bodybuilders often followed higher protein (3.3 g/kg/d), low-fat (0.6 g/kg/d) diets and consumed more carbohydrate and energy than their less successful peers. (5)
A study compared strength-training athletes who consumed 4.4 g/kg/d (an average of 307 grams of protein per day) to athletes who consumed their normal diet (an average of 138 grams of protein per day). The researchers found that the higher protein intake had no effect on body composition. (8)
As you can see, research results regarding protein intake have been inconsistent. Part of the reason for this is that few studies compare specific macro ratios to see which intake works best. Rather, most studies involve researchers observing current trends among bodybuilders, which (as pointed out in the studies) are not usually based on evidence. One consistent observation, however, is that factors other than protein intake, such as training volume, genetics, and supplement use, have a significant impact on results.(2)
So what does this mean for you? When determining macros for bulking, you want to prioritize protein intake, but going overboard with your intake will not necessarily lead to greater gains; it may even lead to increases in fat mass.
How to Calculate Macros for Bulking
If you are new to bulking and your current protein intake is low, start with an intake of 1.6 grams of protein per kilogram of body weight per day. Increase the amount if you don’t start to see results in about a month. If you hit 2.5 grams per kilogram of bodyweight and still don’t see results, consider changes to your workouts before increasing protein intake further. You might also consider increasing your intake of carbohydrates so that you have the energy needed for more intense workouts. Surprisingly, carbs may be the macro you need.
While protein intake during bulking is essential, several studies also point to the importance of carbohydrates during bulking. In fact, several researchers have found that successful professional bodybuilders were likely to have a higher carbohydrate intake than amateurs. Carbohydrates are your body’s preferred source of fuel and are essential for optimal energy during strength training workouts.
So, how do you determine the best macro ratio for you during bulking? Follow this step-by-step method to determine a starting point for your bulking macros:
Determine the calorie intake needed to sustain your current weight and training plan according to the instructions above.
Calculate your protein needs by multiplying your body weight in kilograms by 1.6 (or your desired number). This will give you the number of protein grams needed per day. You will use this as your starting intake for protein. Multiply your protein grams by 4 to determine the number of protein calories you need.
Subtract daily protein calories from total daily calories to determine the remaining “budget” for carbs and fat. Make sure that your carb intake is at least 45% of your total daily calories (up to 65%). Use the remaining calories for (healthy) fat.
Remember, there is no perfect bulking prescription. Finding your perfect recipe will take some time. Pick up a copy of Macro Diet for Dummies to learn how to calculate macros like a pro. The book also provides meal prep recipes and basic nutritional guidance to help you reach your goals. If you are serious about weight training, learning more about nutrition will be worth the effort.
Can You Keep Bulking Forever?
Most athletes who participate in bulking will also participate in a cutting phase at some point. I will cover how long to cut, how many calories during cutting, and cutting macros in a different blog post. But the bottom line is that very few athletes stay in a bulking phase forever. Even if you don’t participate in a cutting phase, you should give your body (and your brain) a break at some point to avoid burnout.
Another concern with bulking forever is getting into a vicious cycle that leads to disordered eating. Researchers have acknowledged the close connection between the bulking/cutting cycle and problematic eating or exercise patterns. In fact, one study author even referred to these dietary strategies as “extreme” and “lacking scientific support.”(4) Other researchers have linked cutting and bulking to eating disorders. (1)
Of course, most athletes will participate in bulking and cutting cycles with no problems at all. At worst, some athletes may start to experience an increase in fat mass when they bulk for too long, or they lose too much muscle while cutting. One study author noted:
“Bodybuilders seem to risk their health in order to increase fat-free mass and then risk their health again to lose fat, but end up losing most of the fat-free mass previously acquired. Maybe it would be more reasonable to gain smaller amounts of muscle mass while minimizing fat gain and then adopt strategies to lose body fat while preserving lean mass.” (3)
The key is to keep your training and diet plan in perspective. Set reasonable goals (about one to two pounds of muscle per month) and reevaluate your program every few months. Take a step back if you start to experience burnout, reach a plateau, or start to gain excess fat. These are signs that your body may need a break.
Sources:
Ganson KT, Cunningham ML, Pila E, Rodgers RF, Murray SB, Nagata JM. "Bulking and cutting" among a national sample of Canadian adolescents and young adults. Eat Weight Disord. 2022 Dec;27(8):3759-3765. doi:10.1007/s40519-022-01470-y
Leaf A, Antonio J. The Effects of Overfeeding on Body Composition: The Role of Macronutrient Composition - A Narrative Review. Int J Exerc Sci. 2017 Dec 1;10(8):1275-1296. doi:10.70252/HPPF5281
Gentil P, de Lira CAB, Paoli A, Dos Santos JAB, da Silva RDT, Junior JRP, da Silva EP, Magosso RF. Nutrition, Pharmacological and Training Strategies Adopted by Six Bodybuilders: Case Report and Critical Review. Eur J Transl Myol. 2017 Mar 24;27(1):6247. doi:10.4081/ejtm.2017.6247
Lenzi JL, Teixeira EL, de Jesus G, Schoenfeld BJ, de Salles Painelli V. Dietary Strategies of Modern Bodybuilders During Different Phases of the Competitive Cycle. J Strength Cond Res. 2021 Sep 1;35(9):2546-2551. doi:10.1519/JSC.0000000000003169
Chappell AJ, Simper T, Helms E. Nutritional strategies of British professional and amateur natural bodybuilders during competition preparation. J Int Soc Sports Nutr. 2019 Aug 22;16(1):35. doi:10.1186/s12970-019-0302-y
Spendlove J, Mitchell L, Gifford J, Hackett D, Slater G, Cobley S, O'Connor H. Dietary Intake of Competitive Bodybuilders. Sports Med. 2015 Jul;45(7):1041-63. doi:10.1007/s40279-015-0329-4
Antonio J, Evans C, Ferrando AA, Stout JR, Antonio B, Cinteo H, Harty P, Arent SM, Candow DG, Forbes SC, Kerksick CM, Pereira F, Gonzalez D, Kreider RB. Common questions and misconceptions about protein supplementation: what does the scientific evidence really show? J Int Soc Sports Nutr. 2024 Dec;21(1):2341903. doi:10.1080/15502783.2024.2341903
Antonio J, Peacock CA, Ellerbroek A, et al. The effects of consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals. J Int Soc Sports Nutr. 2014;11(1):19. doi:10.1186/1550-2783-11-19
Kerksick, C.M., Arent, S., Schoenfeld, B.J. et al. International society of sports nutrition position stand: nutrient timing. J Int Soc Sports Nutr 14, 33 (2017). doi:10.1186/s12970-017-0189-4
Henselmans M, Bjørnsen T, Hedderman R, Vårvik FT. The Effect of Carbohydrate Intake on Strength and Resistance Training Performance: A Systematic Review. Nutrients. 2022 Feb 18;14(4):856. doi:10.3390/nu14040856
