Depending on who you ask, “bulking” has different connotations attached to it. For some, bulking is the way to gain muscle size and strength. For others, bulking is a foolish way to build muscle that results in needless fat gain. Which is it?
To figure out if bulking is the best way for a skinny guy to build muscle, there are a few different questions we have to answer:
- Does a calorie surplus allow you to build muscle faster?
- Can you lose fat and build muscle at the same time?
- Does bulking cause needless fat gain?
- Will bulking make skinny guys skinny-fat?
- What is Bulking?
- Is Bulking the Best Way to Build Muscle?
- The Different Styles of Bulking
- Aggressive Versus Cautious Bulking
- Examples of Successful Bulks
What is Bulking?
There are a few different ways of defining the term “bulking,” and we’ll go over all of them. But let’s start with the basic definitions of bulking, cutting, and body recomposition, then work our way out from there.
- Bulking: going into a calorie surplus (gaining weight) to facilitate muscle growth. What separates bulking from merely “gaining weight,” though, is bulking has an emphasis on gaining muscle while minimizing fat gain.
- Cutting: going into a calorie deficit (losing weight) to make it faster and easier to lose fat. What separates cutting from simply “losing weight,” though, is cutting has an emphasis on losing weight while maintaining or gaining muscle.
If we look at these definitions, they already take body composition into consideration. Bulking is designed to help people build muscle without gaining fat. Cutting is designed to help people burn fat without losing muscle.
- Body recomposition: achieving both fat loss and muscle gain within a given period of time. When someone loses fat while bulking or gains muscle while cutting, they’ve achieved body recomposition. Still, when people talk about “recomps,” they’re usually talking about gaining muscle and losing fat while maintaining the same overall body weight.
- Maintaining: and then, of course, if someone is casually lifting weights and eating a decent diet, but not really getting much leaner or more muscular, then we’d call that maintenance. (And to be clear, there’s absolutely nothing wrong with maintenance. Most strong, healthy people spend the majority of their lives casually maintaining their strength and fitness.)
With body recomposition and maintenance, there’s still an emphasis on body composition, it’s just there’s no emphasis on gaining or losing weight.
To make it dead simple, if someone is gaining weight to build muscle, they’re bulking. If they’re losing weight to lose fat, they’re cutting. And if they’re trying to improve their body composition without gaining or losing weight, then they’re doing a “recomp.”
Is Bulking the Best Way to Build Muscle?
Why I chose to Bulk (Gaining 65 Pounds)
So, first of all, I want to be open about my bias. I started off at 6’2 and 130 pounds. My goal was to build muscle, become bigger, and ultimately weigh in at a lean 150 pounds. So I didn’t really have any choice. No amount of body recomposition could possibly take me from 130 up to 150 pounds. I needed to add extra mass to my frame. I had to bulk.
If I was a skinny-fat 150 pounds, eh, maybe I could have taken a different approach. I could have tried to burn off the fat and replace it with muscle, maintaining a similar bodyweight throughout. Maybe it wouldn’t have been the fastest way to build a lean and muscular physique, but at least it would have been possible. But that wasn’t my plight.
And then, of course, once I hit 150 pounds, I realized that I wanted to be 170 pounds. Then at 170 pounds, I realized I wanted to be 190 pounds. And then 195 pounds. That’s how, between 22 and 32 years old, I gained 65 pounds:
This whole process of gaining weight and muscle is called bulking. I did gain a bit of fat while doing it, but never so much that it was all that noticeable, and certainly never enough that it harmed my health or appearance. Plus, with a couple months spent cutting here and there, I was able to melt the fat away between bulks. In fact, during my more recent bulks, I gained so little fat that I didn’t need to cut at all.
This has given me a pretty clear bias. I gained literally all of my muscle size and strength during these focused periods of gaining weight. Over these past ten years, I’ve spent maybe two years bulking. During those two years, I made all of my progress. During the other eight years, I was lifting weights and eating a decent diet that was rich in protein, but I never saw much muscle growth. The reason for that is simple: I’m not overweight. So if I’m not gaining new weight, where would new muscle come from?
Building Muscle in a Calorie Deficit (Cutting)
If you’re overweight or skinny-fat, we recommend eating in a calorie deficit (to lose weight), following a good hypertrophy training program (to stimulate muscle growth), eating plenty of protein (to maintain/build muscle), and getting enough good sleep every night (to improve nutrient partitioning). If you can do that, you should be able to build muscle while rapidly losing fat.
For example, if we look at a study investigating the effects of combining weight training, cardio, and high-protein diets, we see that the participants were able to gain muscle while losing weight.
However, although it’s realistic to gain some muscle mass while cutting, it’s quite a bit slower and harder. Here’s why:
- Eating fewer calories reduces muscle protein synthesis, even when protein intake is high. That makes it much harder to gain muscle mass. As shown in this study, a reasonable calorie deficit of 500 calories per day (about a pound lost per week) resulted in a 20% decrease in muscle-protein synthesis. This might sound like it would reduce our rate of muscle growth by 20%, but unfortunately, it’s worse than that. Our bodies are always breaking down and rebuilding muscle, with a “normal” rate of muscle-protein synthesis yielding muscle maintenance. A decrease in muscle protein synthesis, then, tends to result in muscle loss. We want the opposite of this.
- A calorie deficit decreases our levels of insulin-like growth factor 1 (IGF-1). Being in a calorie deficit can reduce our levels of IGF-1 by as much as 45% (study). Lower levels of IGF-1 in our muscle fibres can result in slower rates of muscle growth. However, this reduction in IGF-1 was measured in the blood, not in our muscle fibres, and so we wouldn’t expect this to affect muscle growth (study). Still, we want the opposite of this.
- A prolonged calorie deficit reduces testosterone production (study). Fluctuations within the normal testosterone range don’t always affect muscle growth or fat loss, but generally speaking, having higher testosterone levels makes it easier to improve our body composition. Short periods of mild calorie deficits shouldn’t be much of a problem, but even so, it’s certainly not the most anabolic state to be in.
- Eating fewer calories increases growth hormone production. When people eat in a calorie deficit, hypertrophy training causes their levels of growth hormone to rise higher than normal (study). Growth hormone production goes up during fasting periods, too, which is why intermittent fasting increases growth hormone (study). However, despite its name, growth hormone isn’t associated with muscle growth (study).
- Reduced activation of mTOR (study), which controls muscle growth and breakdown, controlling whether we gain or lose muscle. So when we’re trying to build muscle, we want more mTor, not less.
- Lowered immunity (study). Another side-effect of being in a prolonged calorie deficit, especially when already fairly lean, is that it can reduce our immunity. Exercise improves our immunity, but even so, we need to be a bit more cautious with how hard we train.
So the main downside to being in a calorie deficit is that it reduces our rate of muscle-protein synthesis and activation of mTOR, increasing muscle breakdown and reducing our rate of muscle growth. These aren’t insurmountable problems, but they are problems.
Now, keep in mind that hypertrophy training can be quite powerful. If we add hypertrophy training to a modest calorie deficit, it can bring our rates of muscle protein synthesis almost back to baseline (study). And if we combine a good hypertrophy program with a higher protein intake, we can rise above baseline, making it possible to maintain or even gain muscle while losing weight (study). If we add in a good sleep routine, manage our stress, maybe supplement with a bit of creatine, you can see how we’d be able to overcome these disadvantages. But even so, that 20% reduction remains. Our rates of muscle growth never rise as high as they normally would, and so building muscle is slower, harder, and more finicky.
Furthermore, the increase in muscle protein synthesis that we get from training only lasts a few days (study, study), and the boost we get from consuming protein only lasts a few hours. Whenever that effect fades and we go back to baseline, the calorie deficit will plummet us back down into lower rates of muscle protein synthesis. This means that we often find ourselves building muscle right after lifting weights and eating protein, then losing muscle at other points of the day/week. If we weren’t eating so few calories, that wouldn’t happen. We’d build muscle during the high points and maintain muscle during the low points. It would be much easier to come out ahead.
Plus, the leaner you are, the more lifting experience you have, and the more muscle you’ve already gained, the harder it becomes to gain muscle in a calorie deficit. In fact, for a lot of intermediate lifters, it can be a real challenge to even maintain muscle mass during a cut.
If you’re trying to maximize your rate of muscle growth or if you’re having trouble gaining size and strength, then it’s much easier to build muscle when you’re gaining weight—when you’re bulking.
Building Muscle at Maintenance (Body Recomposition)
Building muscle at maintenance is much easier than while cutting. Instead of rising levels of cortisol, lower testosterone and IGF-1, and reduced rates of muscle protein synthesis, now everything is back at baseline. By adding in a good hypertrophy training routine, eating enough protein, getting enough good sleep, and improving your lifestyle, you’ll be in a good position to gain muscle and strength, even if you aren’t enough calories to gain weight.
For example, if we look at a study investigating how sleep affects body composition, we see that the participants who were put on a lifting, diet, and sleep program were able to gain muscle and lose fat while staying at the same body weight.
However, building muscle is a costly endeavour. That extra energy has come from somewhere. And since it’s not coming from a calorie surplus, it will need to come from your body fat. That’s not much of a problem for someone who’s overweight. They have a surplus of body fat and so their body won’t fight to keep it (study, study). In fact, if we look at overweight beginners, it’s unclear if there’s even a benefit to eating in a calorie surplus. They build muscle just fine. But if you’re already under 15–20% body fat, you already have a healthy amount of fat. Your body won’t necessarily want to lose more of it. You might still be able to achieve body recomposition, but it will be a long, slow, hard, and finicky process.
But the time you get quite lean—closer to 12–15% body fat—your body will be even more reluctant to lose fat. It wants to have that energy reserve. It won’t want to invest in muscle growth if there isn’t an abundance of calories coming in. At this point, no matter how good your hypertrophy program is, you’ll run into a plateau. You won’t be able to build muscle without gaining weight because there’s nowhere for that extra energy to come from. This is the issue for most naturally skinny guys. To gain muscle, they need to gain weight.
There are exceptions, of course. If you’re untrained, if you’re regaining lost muscle mass, or if you’re still quite small, then it might still be possible to build a little bit of muscle without gaining weight, even with a fairly low body-fat percentage. But eventually, that will stop working. You’ll hit a plateau. It’s not a reliable way to build muscle.
For overweight beginners and people who are getting back into shape, it’s possible to build muscle and lose fat at the same time. Even for some intermediate lifters, it’s possible to gain a little bit of muscle while losing a little bit of fat. It’s hard and slow, though, and you’ll eventually hit a plateau.
Building Muscle in a Surplus (Bulking)
Most bodybuilders, powerlifters, and athletes go through periods of intentionally gaining weight. Bodybuilders call it their “offseason,” powerlifters call it a “massing phase,” and almost everyone else calls it “bulking.” These bulking phases are designed to help people build muscle while minimizing fat gain, and they’ve been a popular way to build muscle for several decades now.
There are some interesting things that happen when we gain weight:
- Even without weight training, eating in a calorie surplus causes muscle growth (study, study). Most people who gain weight build around one pound of muscle for every two pounds of fat they gain. This makes their body composition worse, of course. They become overweight. But even without lifting weights or eating enough protein, people can gain quite a lot of muscle.
- A calorie surplus may increase testosterone, IGF-1, and insulin (study). However, this seems to hinge on remaining fairly lean, as higher levels of body fat can reduce testosterone (study, study). So when you’re bulking, you should be resistance training, eating enough protein, and getting enough sleep. That way your gains are more likely to be lean. Furthermore, these small increases in anabolic hormones, while nice, may not lead to extra muscle growth (study, study).
- Eating in a calorie surplus allows us to eat an abundance of carbs, protein, and fat, all of which can help us build muscle. The most obvious benefit of eating in a calorie surplus is simply that there’s an abundance of energy available that can be invested in muscle growth. With the higher amounts of muscle protein synthesis from hypertrophy training and eating protein, that’s the perfect combination for muscle growth.
Overall, a calorie surplus creates a favourable hormonal environment, muscle protein synthesis is revved up into overdrive, and we have an abundance of calories and protein to build muscle with. As a result, there are numerous studies showing rapid gains in lean muscle mass when the participants are in a calorie surplus versus no muscle growth whatsoever when the participants merely ate enough to maintain their weight.
For instance, in this study on untrained men, some of the participants were given 1,800 calories from carbs (as a weight gainer shake) every day. Over the course of eight weeks, they gained seven pounds of body weight, gained 7.5 pounds of lean mass, and lost 0.5 pounds of fat. The control group lifted weights but weren’t told to increase their calorie intake. They gained a bit of strength but weren’t able to gain a significant amount of muscle mass.
These kinds of results pop up all over the place. For instance, when we were writing our article about whether ketogenic diets were good for building muscle, we came across this study:
The participants following the ketogenic diet weren’t able to get into a calorie surplus and wound up losing muscle, even though they were hypertrophy training. The high-carb group, on the other hand, was able to get into a calorie surplus. They gained three pounds of lean mass in eight weeks while losing a pound of fat.
What’s interesting about this study is that it was done on intermediate lifters. So if we forget about that ketogenic group, we see that beginners were able to gain almost a pound of lean mass per week with a high-carb diet, whereas intermediate lifters were gaining lean mass at half that rate. Both groups lost fat while bulking.
If we look at recommendations for maximizing rates of muscle growth, we also see recommendations for bulking. This study recommends a calorie surplus of 200–300 calories for maximizing rates of muscle growth. And in this study, Eric Helms, PhD, and Brad Dieter, PhD, recommend a calorie surplus of 350–500 calories per day to maximize rates of muscle growth.
Now, this doesn’t mean that we need to count calories. This study found that in elite athletes, intuitively gaining weight worked better than assigning a specific calorie surplus. Over the course of ten weeks, the average participant gained around two pounds. They weren’t gaining weight on purpose, and they weren’t gaining weight all that quickly, but it seems to have been enough to maximize muscle growth nonetheless. In fact, the participants who were told to eat 500 extra calories overshot their targets and wound up gaining some extra fat. Mind you, this study was on elite athletes who were already near their genetic muscular potential. Still, I think there are two takeaways:
- Some people naturally eat in a small calorie surplus. After all, most people become overweight by accident. And this may be exaggerated when following a rigorous hypertrophy program. Hard workouts make some people hungrier. They intuitively eat enough to build muscle.
- For advanced lifters who are already near their genetic muscular potential, muscle growth is very slow, and so even a small calorie surplus may be enough to maximize rates of muscle growth.
Of course, if you’re like me, then you don’t naturally eat in a calorie surplus. Unless you’re intentionally trying to bulk up, your weight might stay the same. In that case, it helps to intentionally bulk.
The Different Styles of Bulking
- Dreamer Bulking: when someone does such a poor job of bulking that they appear to be gaining pure fat. This is the easiest form of bulking to criticize, but most people who are big and strong have accidentally dreamer bulked at least once. I certainly have. Usually, we learn some valuable lessons, gain some strength, and build at least a bit of muscle. It often winds up being worthwhile in the end (once you’ve burned off the extra fat). Still, you shouldn’t do it on purpose.
- Dirty Bulking: this is often done by eating a “see-food” diet, where you eat whatever the hell you want, don’t track calories, and wind up eating a diet fairly high in greasy junk food and sweets. Even if you make fairly decent food choices, you may simply eat too much, gaining weight too quickly and sporadically. Some people get lucky, getting lean gains while dreamer bulking. More often than not, though, it results in a dreamer bulk.
- Clean Bulking: bulking while avoiding junk food. The classic “clean” diet is made up of foods like chicken breast, broccoli, rice, oats, whey protein, ground meat, cottage cheese, Greek yogurt, olive oil, nuts, and fruits. These are all great bulking foods, and there’s a reason why they’re so popular. Still, you don’t need to eat a “clean” diet to get good bulking results. If most of your diet is built around whole foods, there’s nothing wrong with having some dessert here and there.
- Lean Bulking: bulking while trying to intentionally minimize fat gain. This is often done through rigorous calorie tracking, smart food choices, following a good hypertrophy training routine, and eating a fairly small calorie surplus.
A lot of fitness experts choose their least favourite definition and then criticize bulking as a whole. Maybe you’ve heard that kind of argument before. Here are some examples:
- People who (dreamer) bulk gain a disproportionate amount of fat. It’s better to build muscle more leanly. Thing is, gaining muscle leanly is still bulking. It’s called a “lean bulk.”
- People who (dirty) bulk eat a bunch of junk food, which is bad for their health and causes a bunch of needless fat gain. It’s better to eat a more nutritious diet. But again, eating a nutritious diet while bulking is still bulking. That’s called a “clean bulk.”
- People who (aggressively) bulk gain weight far more quickly than their bodies can build muscle, which doesn’t work for anybody except for skinny beginners. It’s better to gain weight more slowly. And once again, this isn’t a criticism of bulking, it’s just a criticism of bulking too quickly.
In all of these cases, it sounds to me like people are picking a style of bulking that they dislike, using that to criticize bulking in general, and then proposing a better way to build muscle… which is still bulking. This is why you’ll often hear other terms used instead of bulking, such as a “gaining phase” or a “massing phase” or a “lean gain” phase. They’re trying to avoid the stigma that can be associated with dirty/dreamer bulking. But if the person is gaining weight with the goal of building muscle, I’d still call it bulking.
With that said, sometimes bulking should be criticized. Do some people bulk too quickly? Yes. Do some people eat too much junk food while bulking? Absolutely. Do some people have unrealistic expectations about how fast they can build muscle? Definitely. But does mean bulking is bad? No. It just means that we should, a) bulk properly, and b) choose the style of bulking that suits us best.
On my journey from 130 to 195 pounds, I’ve tried all the different styles of bulking. My business partner, Marco (above), gained 63 pounds while getting his health sciences degree and his strength coach certifications. My roommates have bulked up. My little sister has bulked up. My wife has bulked up (below). And we’ve helped over 10,000 skinny people bulk up. We’re bulking connoisseurs.
Of all the different styles of bulking, our two favourites are:
- Aggressive bulking: a more aggressive approach to bulking that works especially well for hardgainers who are both underweight and naturally lean. It involves driving into a large daily calorie surplus (of 500 or more calories) and aiming to gain a full pound per week—sometimes more. The goal is to build muscle as quickly as possible, but even so, it’s still wise to keep an eye on fat gains. We aren’t trying to get fat, we’re just trying to maximize muscle growth. If you’re gaining a noticeable amount of fat, slow it down. Bulk more cautiously.
- Cautious bulking: a more fat-conscious approach to bulking works best for guys who are softer or more skinny-fat. They might still be underweight, still eager to get bigger, but they’re trying to keep fat gain to an absolute minimum—maybe even lose a tidbit of fat while bulking. For this, we recommend bulking more slowly, aiming for around 0.5 pounds gained per week. Sometimes less.
We sort of invented these terms. Just as other fitness experts have discovered, it can help to have terms that define specific methodologies. For instance, if we talk about “clean” bulking, people might mistakenly assume that we’re deathly afraid of carbs or sugar, or that we discourage people from eating dessert. But all of those things can be part of a healthy and effective lean bulking diet. That’s why we don’t use the “clean bulking” term, even though we recommend eating a good bulking diet. So this isn’t me throwing shade at people who want to call their approach to bulking “massing” or “gaintaining” or whatever. That’s totally fine. But as far as I’m concerned, they’re all just different styles of bulking.
Aggressive Versus Cautious Bulking
There was a recent study looking at different rates of weight gain and how they impacted muscle growth. The participants who gained weight more quickly gained over twice as much muscle, whereas the participants who gained weight more slowly gained half as much fat:
This shows us that there are multiple ways to bulk properly. The person who wants to gain muscle as quickly as possible can increase his rate of muscle growth by gaining weight more quickly (aggressive bulking), whereas the person who wants to stay as lean as possible can adopt a slower pace (cautious bulking).
Now, the assumption here might be that aggressive bulking always means gaining more fat whereas cautious bulking means gaining less fat. That’s often the case, but it’s not always so. For instance, check out GK’s aggressive bulking transformation while doing our Bony to Beastly Program:
He gained an average of 1.5 pounds per week for twenty weeks in a row, gaining a total of 29 pounds. That’s an extremely aggressive bulk, but he had no visible fat gain. That’s why we call it aggressive bulking instead of dreamer bulking, and cautious bulking instead of lean bulking. Fat gain isn’t always tied to the rate of weight gain. As we’ve seen in the studies above, it’s even possible to bulk quite quickly while losing fat.
Examples of Successful Bulks
Now that we’ve talked about the different advantages and types of bulking, let’s go over some examples. Here’s one of our members, Eddi, who decided to bulk before his 60th birthday. Because he was starting out so thin and so lean, he was able to bulk quite aggressively without gaining a noticeable amount of body fat, let alone having his body-fat percentage rise to the point where anyone would ever call him fat.
Now, Eddi was starting off fairly thin. He was able to take advantage of the phase of rapid muscle growth that’s often called newbie gains. What happens when we take a skinny guy who’s already in the habit of lifting weights and has already gained their first twenty pounds?
Here’s my own three-month bulking progress. Depending on how kind you are, you may be able to tell that I was already in the habit of lifting weights on Day 0. In fact, I had already successfully bulked up from 130 to 150 pounds. My shoulders had started growing broader and my chest was starting to separate itself from my stomach.
Even so, even after gaining twenty pounds, I still chose to bulk aggressively. Over three months, I gained just under 25 pounds, putting my average weight gain at nearly two pounds per week. Now, my gains weren’t entirely lean. I’m not trying to say that I gained 25 pounds of muscle. But my fat gain was modest enough that it wasn’t that noticeable. My bigger muscles hid the added fat. And I was still well within the healthy body-fat percentage range, so who cares? I certainly didn’t. I was thrilled!
And I’m not an outlier, either. We have plenty of intermediate lifters who choose to do more aggressive bulks. For instance, here’s Johnny gaining over a pound per week for five months straight:
Like me, Johnny was already lifting weights, had already gained muscle, was already competent at doing the big compound lifts. And he was still able to benefit from an aggressive approach to bulking.
What you’ll notice, though, is that in all of these cases, our members have a couple of things in common:
- We’re starting off quite lean, meaning that even if we gain a couple of body-fat percentage points, it doesn’t really matter. Going from 11% to 14% body fat isn’t unhealthy, it doesn’t harm our appearance, and it barely even affects the appearance of our abs.
- We’re still at least somewhat thin, meaning that we’re still relatively far away from our genetic muscular potential. With a good hypertrophy program, enough protein, a good diet, and clever healthy lifestyle changes, we can still build muscle rather fast without being limited by our genetics.
And that brings us to the cautious bulks. With cautious bulks, we still do everything in our power to build muscle, but we slow down the rate of weight gain to reduce the risk of the surplus calories spilling over into fat gain.
Here’s an example of a successful cautious bulk. Mickey is “only” gaining half a pound per week, but fast forward a few months, and it adds up to an appreciable amount of muscle without noticeable fat gain. Is that better than aggressive bulking? Maybe. It depends on the person.
For another example, here’s Abousha. He had to bulk while travelling for work, making do with the equipment and food that was available. As a result, he bulked at a slower pace. And it worked out great:
How fast someone should bulk depends on the person, their circumstances, their goals, and how scared they are of gaining fat. For me, I don’t mind cutting. Eating less food is easy. In some ways, I prefer it. So the idea of my body-fat percentage going up a couple of points never scared me. I knew I could get rid of it. But not everyone thinks that way. It’s totally up to you.
Overweight beginners are often able to build muscle and lose fat without needing to worry about gaining or losing weight. This is called body recomposition. The trouble is, if you’re already lean, or if you’re finding it hard to continue making progress, then it doesn’t work very well. And for skinny guys, it usually doesn’t work at all.
If you’re skinny, you’re new to lifting weights, or you’re regaining lost muscle, you may benefit from gaining a pound (or more) per week. We call this aggressive bulking. It’s the fastest, most powerful way to build muscle.
If you’re already muscular, an intermediate lifter, or your body-fat percentage is already over 15–20%, you might want to bulk more cautiously. We recommend gaining around half a pound per week. That’s more than enough weight gain to reliably build muscle, and it will increase your chances of making lean gains.
Regardless of how aggressively you bulk, if you notice that you’re gaining fat, consider adjusting your workout routine, adjusting your diet, adjusting your lifestyle, or slowing things down. It’s usually best to minimize fat gain while bulking, even if that means gaining muscle at a slightly slower pace. Although, with that said, don’t stress about gaining fat, either. It’s easy to burn off. Just don’t gain it on purpose.
If you want more muscle-building information, we have a free bulking newsletter for skinny guys. If you want a full foundational bulking program, including a 5-month full-body workout routine, diet guide, recipe book, and online coaching, check out our Bony to Beastly Bulking Program. Or, if you want a customizable intermediate bulking program, check out our Outlift Program.