Bulking means you’re consuming more calories than you need strictly speaking, according to your maintenance level. So you create a calorie surplus. But how big should that actually be, if you aspire to maximum gains?
BULKING LIKE NATURAL
The term bulking is somewhat misleading, as it suggests that you should eat as much as you can, or at least a lot. This is indeed the case with enhanced bodybuilding, but natural bodybuilding is a completely different profession. As a natural, you would mainly grow fat and not muscle mass, if you were eating recklessly.
The essence is that you only need a relatively small calorie surplus and that the calorie requirement of novice and intermediate strength athletes is greater than that of experienced ones.
BEGINNERS AND INTERMEDIATES
The review states that novice and intermediate natural bodybuilders (0-3 years of serious training) should eat about 20 to 40% above their maintenance level if they want to optimize their muscle growth. In practice, that usually comes down to 500-1000 kcal .
The muscle gain is probably greatest when the surplus is mainly obtained from extra carbohydrates. Carbohydrates are the main source of energy for strength training. In addition, the surplus for 20-40 grams must consist of proteins, or 0.4 g/kg body weight .
Absolute beginners and returners do not necessarily have to use a calorie surplus: they can gain muscle mass even with a negative energy balance (body recomposition), although they may gain less quickly.
Advanced natural bodybuilders (> 3 years of serious training) can suffice with a smaller calorie surplus, as they have a smaller growth potential. As an advanced athlete you have already had most of your gains and you will have to settle for very slow muscle growth. According to Aragon and Schoenfeld, this includes a modest calorie surplus of 10-20%, or usually 250-500 kcal .
That surplus is best obtained mainly from proteins, namely also 20-40 grams, or 0.4 g/kg body weight, and therefore relatively few extra carbohydrates.
Update 8-8-2023: a new study, conducted among experienced strength athletes, shows that there is little difference between a small (5%) and a higher (15%) surplus. That while with the high surplus considerably more fat is stored. According to coach Steve Hall, you should aim for a weight gain of 0.25 to 0.5 grams per kilogram of body weight per week with your surplus.
Keep in mind that bulking, especially if you are advanced, is always accompanied by some increase in fat percentage. As long as that stays within limits and you regularly build in a cutting phase or mini cut that’s no problem.
No matter what calorie surplus you apply, you should eat enough protein every day, namely at least 1.6 g/kg body weight. It is also important that you calculate your maintenance level as accurately as possible. How to do that as a bodybuilder is explained in this article.