Illustration of the tortoise and the hare

I remember being skinny and wanting to gain weight FAST. I didn’t just want to be muscular yesterday, I wanted to be muscular in every single one of my previous lives.

We aren’t trying to gain weight, though, we’re trying to gain muscle. And if we bulk up too fast, won’t we become skinny-fat? That can happen. Not to everyone, but it can happen to some of us sometimes. It’s important to understand those risk factors.

Over the past eight years, we’ve helped nearly 10,000 skinny guys bulk up. We’ve helped them bulk fast, we’ve helped them bulk lean, and everything in-between. Even when dealing with naturally skinny guys, there’s no one-size-fits-all approach.

Let’s talk about the pros and cons of gaining muscle quickly versus gaining it leanly. That way, you’ll know exactly how much weight you should be trying to gain on the scale each week.

Before and after illustration of a skinny hardgainer ectomorph becoming muscular.

The Tortoise and the Hare

Do Slow and Steady Gains Win the Race?

A new study looked into how different rates of weight gain affected muscle growth and fat gains. Does gaining weight faster yield extra muscle growth? Will gaining weight slower make our gains leaner? This study answers those questions.

Now for the fun part. This study was reviewed in Monthly Applications in Strength Sport (MASS) by Eric Helms, PhD. The title of his review was: When Gaining Muscle, the Tortoise Beats the Hare.

Is that true?

An illustration of the tortoise and the hare from Aesop's Fables.

So, first of all, as you probably know, there’s this old Aesop’s Fable about a tortoise and a hare. I’m sure you’ve heard it before. The story goes something like this:

  • Once upon a time, a hare mocked a tortoise. “You’re so slow! How do you even get anywhere?”
  • The tortoise wasn’t fazed. “I get places faster than you might think. I bet I could even beat you in a race!”
  • The hare laughed. What a joke! “Alright, let’s race.”
  • When the race began, the hare bounded out of sight, leaving the tortoise plodding along in his dust. So far, so good. But the hare soon tired and took a nap.
  • The tortoise paced himself. He marched slowly, yes, but he marched steadily. And while the hare napped, the tortoise overtook him, winning the race.

The moral of the story, of course, is that slow and steady wins the race. Persistence outperforms speed.

But what if the hare took a shorter nap? Or what if the tortoise was a little bit slower? Or what if the hare raced all the way to the finish line and then took his nap?

With a story like this, the details make all the difference.

How Slow Are Lean Gains?

Okay, now let’s talk about the new bulking study. The researchers took intermediate natural bodybuilders and split them into two groups.

  1. The tortoise group ate a modest calorie surplus and gained 1 pound per week on the scale. After 4 weeks, they had gained 2.6 pounds of muscle and 0.7 pounds of fat.
  2. The hare group ate a massive calorie surplus and gained 2 pounds per week on the scale. After 4 weeks, they had gained 5.3 pounds of muscle and 4 pounds of fat.
Gaining weight more quickly yielded far more muscle and fat.

Quick note: when Dr Helms reviewed this study, he noticed that the researchers used a poor way of calculating muscle and fat gains. So I’m using the corrected results from the MASS review, not from the study itself.

Anyway, it’s easy to see why Helms favoured the tortoises. By eating in a smaller calorie surplus, they were able to gain muscle three times as leanly:

Gaining weight more slowly yielded a much better ratio of muscle-to-fat gains.

Does that mean that the tortoises won the race, though? I guess that depends on what the race is. Around here, we’re all about helping skinny guys bulk up, so we’re in a race to build muscle. By Dr Helms’ standards, too, he’s talking about muscle growth: When it Comes to Building Muscle, the Tortoise Beats the Hare.

So far, though, we’ve only talked about the ratio of muscle-to-fat gains. That doesn’t tell us anything about which group actually won the race. To do that, we need to talk about rates of muscle growth:

  1. The tortoise group gained 0.7 pounds of lean mass per week, gaining a total of 2.6 pounds over the course of the 4-week study.
  2. The hare group gained 1.3 pounds of lean mass per week, gaining a total of 5.3 pounds over the course of the 4-week study.

If this is a race to build muscle, then the hare group absolutely annihilated the tortoise group. It’s not even close. The hares gained muscle twice as fast:

If you want to gain muscle fast, then gain weight fast.

This is serious muscle growth, too. These are intermediate natural bodybuilders who are gaining over a pound of lean mass every week. They’re gaining fat, too, sure, but that’s a fearsome rate of muscle growth.

Now, not all lean mass is muscle growth. In fact, even fat gains contain some lean mass. We can’t say that these bodybuilders were gaining 1.3 pounds of muscle every week. However, most of the lean mass that we gain tends to be muscle.

Is Bulking/Cutting Faster than Lean Gains?

That brings us back to the story of the tortoise and the hare. Remember, the hare didn’t lose the race because he was slower, he lost the race because he had to take a break in the middle.

If we’re talking about bulking, the hares may need to take a break from bulking to cut off the extra fat they gained. We’re talking about bulking + cutting vs lean gains.

  1. The tortoise group gained 0.7 pounds of fat.
  2. The hare group gained 4 pounds of fat.

Now, keep in mind that the hare group also gained more lean mass. The extra fat will be spread thinner over much larger muscles. And besides, going up a couple of body-fat percentage points might not even matter. In fact, it may even help.

For example, if someone is going from 9% up to 14%, the extra fat will make them look bigger in clothes, and it will give them a fuller face and a thicker neck. That will make most guys look noticeably stronger and healthier:

Most people look best with a body-fat percentage between 11–15%.

Not only that, but moving up into a healthier body-fat percentage can give us more testosterone, less cortisol, a stronger immune system, and more energy (study, study, study, study).

But for the sake of simplicity, let’s say that the hare group wants to lose that extra 3.3 pounds of fat.

Losing such a small amount of fat can be fast, especially for skinny guys like us. If we cut hard, we could lose it in a single week. That’s extreme, though. Let’s be generous. Let’s say it takes the hares three weeks to lose that extra fat. After all, we’re talking about the amount of fat we can lose while napping.

During these three weeks, the tortoises are still plodding along. They’re still gaining their 0.7 pounds of lean mass per week. Will they catch the hares?

The next thing we need to do is determine our finish line. I dig twenty-pound bulks. That’s usually enough to turn a skinny guy into a fit guy, or a fit guy into a strong guy:

Illustration of skinny, fit, and strong male body types.

So let’s say the goal is to gain twenty pounds of muscle.

Now we can plot out our race:

  • The tortoises gain 0.65 pounds of muscle every week, so it takes them 31 weeks to gain 20 pounds of muscle.
  • The hares gain 1.33 pounds of muscle every week, but need to take a 3-week break every 4 weeks. That brings their rate of muscle growth down to 0.76 pounds per week. At that rate, it takes them 26 weeks to gain their 20 pounds of muscle.

In this case, the hares beat the tortoises by a whopping five weeks.

Was the Tortoise Even Bulking Slowly?

My favourite thing about this study is the surprise plot twist. Even the tortoises were bulking hard. I mean, if you do some googling about how much weight intermediate lifters should gain per week, here’s what you’ll find:

  • Eric Helms from MASS: 0.5–1.5% of body weight gained per month. For a 150-pound guy, that’s 0.2–0.5 pounds per week.
  • Andy Morgan from Ripped Body: 1–2% of body weight gained per month. That’s 0.3–0.7 pounds per week.
  • Steve Kamb from Nerd Fitness: 2 pounds gained per month. That’s a little under 0.5 pounds per week.

There’s only one exception to the rule:

  • Mike Matthews (Legion Athletics): Aim to gain 0.5–1 pound per week. (And I love this, by the way.)

As you can see, Mike Matthews has by far the most aggressive recommendation. And even then, the supposed tortoise is bulking at the upper limit of that range.

The tortoise is hardly a tortoise. He’s gaining weight at twice the speed that most people recommend, and he’s making lean gains while he does it.

In fact, if you look at a little closer, you can see that the tortoise is really just a hare in disguise. He just shaved his whiskers, painted himself green, tied his ears around his neck, and hid inside a turtle shell. I mean, scroll up and look at that thing. It’s obvious that he’s a hare.

Anyway, here’s what happens if we add the typical rate of weight gain to the graph:

The “tortoise” gaining a pound of muscle per week is actually an argument in favour of bulking fast. It shows that even while gaining a full pound per week, we may be able to make lean gains.

Now, don’t get me wrong, some guys do benefit from bulking more slowly. And other guys may benefit from bulking faster. I think that anywhere from 0.5–2 pounds per week can make sense.

But a pound per week is a good default. And a pound per week is fast.

Why is a Big Calorie Surplus so Effective?

The thing with gaining weight slowly is that your hormones will be fairly average. That’s not bad by any means by any means. But it’s not ideal, either.

By gearing into a larger calorie surplus, you’ll gain a few important advantages:

  • Constant nutrient influx, allowing us to build muscle all day long.
  • More testosterone and insulin, improving our ability to build muscle.
  • More glycogen packed into our muscles, improving workout performance and muscle growth.
  • Activation of mTOR, which allows us to construct more muscle.
  • More weight gain. After all, even simply gaining weight will promote muscle growth.

In the words of Mike Israetel, PhD:

All else being equal, eating more is the most powerful tool for muscle gain, as long as you’re training hard.

–Mike Israetel, PhD

How to Know if You Should Bulk Fast

At this point, we’ve seen that bulking very fast is great for gaining tremendous amounts of muscle. We’ve also seen that bulking moderately fast is great for gaining muscle leanly. Both approaches involve rapidly gaining weight, and both approaches can work wonders.

But there’s more than just this one bulking study to consider. Dr Helms points to this older study, where the hare group was eating 600 calories more per day than the tortoise group, which proved to be too much. They gained slightly more muscle but twice as much fat.

What’s interesting is that the hares were only gaining about a pound per week. That’s not even all that fast, and yet most of their gains were fat. So it’s clear that in some circumstances, it’s better to gain weight more slowly.

On the other hand, we also have plenty of research showing rapid rates of muscle gain:

  • This study found that beginners were able to gain 9 pounds of muscle during their first 8 weeks of working out.
  • In this study, another group of beginners were able to gain an average of 12 pounds of muscle during their first 10 weeks of working out.
  • In another study, beginners were able to gain 15 pounds of muscle during their first 12 weeks of lifting weights.

In all of these studies, the body composition changes were incredible. In one of them, they even lost fat while gaining more than a pound of muscle per week. This means that there are clearly situations where it pays to gain weight more quickly.

Reasons to Gain Weight Slowly

  • Strength training: Strength training is great for gaining strength, not for building muscle. If you’re doing a strength training program, you’ll want to gain weight more slowly.
  • Upper-body emphasis: Over half of your muscle mass is in your lower body. Your quads are your biggest muscles, then your glutes, then calves, then hamstrings. If you aren’t squatting and deadlifting hard, you’ll want to gain more slowly.
  • Fatphobia: if the idea of gaining some fat scares you, you may as well play it safe and bulk more slowly.
  • Higher body-fat percentage: if you’re pushing 15% body fat, gaining more fat might harm your appearance. If you’re already pushing 20%, gaining more fat could even hurt your health.

However, even if you’re following a good bulking program, you may still want to bulk more slowly. We’ve had some clients do great with slower bulks. Here’s a sweet progress update from Mikey:

Before and after photo of a skinny ectomorph building muscle and bulking up.

He’s halfway through our bulking program and has been gaining an average of 0.5 pounds per week. I can’t really imagine a bulk going better than this. Super lean gains.

Reasons to Gain Weight Quickly

  • You’re skinny: the skinnier you are, the more quickly you can build muscle.
  • You’re a beginner: if you’re new to lifting weights, your muscles will respond very well to it.
  • You’re naturally lean: if you’re naturally lean, chances are that you have fewer fat cells. You’ll be less likely to gain fat, and even if you do, it will melt off afterwards.
  • You’re a hardgainer: if you’re a skinny guy who just can’t gain weight, try being more aggressive with it. Your body will naturally fight off the fat gains anyway. It’s good at that.
  • Hypertrophy training: workouts designed specifically for muscle growth will stimulate more muscle growth. (Obviously.)
  • High-carb diet: if your diet is high in carbs (as opposed to fat) then you’ll be able to gain muscle more quickly and leanly.
  • Great sleep: if you’re able to get a good 8 hours of sleep every night, you’ll be able to build muscle faster and leaner.
  • High g-flux: if you have an active lifestyle, you’ll resist fat gain. Doing cardio and spending more time on your feet will allow you to bulk the most aggressively of all.

I’ve always bulked fast. During every one of my bulks, I’ve aimed to gain at least a pound per week. Then, to mitigate fat gain, I tried to optimize my training, diet, and lifestyle.

As a beginner, my gains were lean. As an intermediate, some fat came along for the ride. In either case, I would bulk fast and then rest hard. That’s how I gained 55 pounds in two years:

Before and after photo of a skinny guy's bulking transformation
During each of these bulks, I tried to gain at least a pound per week.

Over those two years, I bulked hard for 11 months and took things easy for 13 months. That means that while I was bulking, I gained 1.25 pounds per week on average.

We’ve used this approach with about half of our clients, too. Here’s Hugo’s one-year bulking transformation:

Before and after photo of a skinny guy gaining muscle in one year

Mind you, I’ll admit a bias here. As much as I hate identity politics, let’s be real, hares have a thinner body type. They’re ectomorphs. As Seth Godin would say, they’re part of our tribe. Tortoises are shorter and rounder, and I’m sure they’re very nice, but they’re endomorphs. They’re that pesky body type who keeps out-benching us. I don’t like it.

But despite my bias, I think the facts bear me out. In fact, in situations like ours, even Dr Helms agrees:

Thus, large surplus gaining diets (among natural lifters) should probably be relegated to novice stages and only among relatively lean lifters who can afford to gain some body fat in the process.

–Eric Helms, PhD

After helping nearly 10,000 skinny people bulk up, we’ve come to the same conclusion. After all, many of us skinny guys are in the perfect situation for an aggressive bulk.

How Quickly Can a Skinny Beginner Build Muscle?

When someone first starts bulking, they go through a period of rapid muscle growth. This phenomenon is called newbie gains.

As the weeks go by, these newbie gains fade. With every inch we add to our biceps, it becomes a little harder to add another. This is the law of diminishing returns.

If you plotted out a beginner’s muscle growth, it would look like this:

How quickly can a beginner build muscle (newbie gains graph)

However, we aren’t just beginners, we’re skinny beginners. We’re even further away from our genetic potential than the average man. As a result, the effect compounds:

How quickly can a skinny beginner build muscle (newbie gains graph)

Here’s our article about how big and strong you can get as a skinny guy. Your potential is probably greater than you think. But the point is, if you’re still skinny, chances are that you can build muscle incredibly quickly.

Aggressive Bulking for Beginners

Many skinny beginners are able to gain upwards of two pounds per week without any visible fat gain. Not everyone can do it, and results here vary wildly, but we see it quite often.

If you look at our client transformations, you’ll see that plenty of guys are able to gain more than a pound per week without any noticeable fat gain, especially during their first 5–10 weeks of bulking.

In fact, Jared himself gained over twenty pounds during his first month of bulking without any visible fat gain. I had never seen anything like it. Since then, we’ve seen a handful of other guys do the same. Given how rare that is, we don’t recommend it. But it happens sometimes.

Here’s another cool example of lean gains while bulking fast:

Before and after photo of a skinny guy bulking up and becoming muscular.

Now, to reiterate, this isn’t to say that you’ll get these exact same results. This is just to say that as skinny beginners who are bulking for the first time, we’re in a great position to gain muscle fast.

In our experience, guys who are starting off lean and underweight (with a BMI under 18) often benefit from gaining 1–2 pounds per week. Then, when they’re no longer underweight, we recommend slowing it down to 0.5–1 pound per week.

Pedal to the metal, baby.

Lean Bulking for Beginners

Most naturally skinny guys are able to build muscle quickly and leanly. Gaining weight more slowly isn’t leaner bulking, it’s just slower bulking.

However, not all skinny guys are naturally lean. We aren’t all starting our bulks at 12% body fat. That can change things.

If you’re starting at 15% and you bulk up to 20%, you’re going to start looking out of shape. You won’t be able to see the muscle that you’re building:

Illustration of a guy bulking at 15% and 20% body fat

That can be hard on some skinny guys. They’re fed up with being small and weak, so they dive into an aggressive bulk. But because they have a higher body-fat percentage, it only makes them even more skinny-fat.

If you’re already up over 15% and feeling a bit soft, it’s often better to shoot for slow and steady lean gains. You won’t build muscle as fast, but you’ll be able to bulk for longer, and you may even lose some fat while doing it. That way your transformation looks more like this:

If you’re already pushing 20% body fat, we’ve got a whole different protocol for you. Here’s our article for skinny-fat guys.

Even for naturally lean guys, though, aggressive bulking will eventually lead to fat gains. Once you move beyond that beginner stage, your ratio of muscle-to-fat gains will drop.

And besides, beginners mess up sometimes. So far we’ve been talking about how beginners can bulk up incredibly fast. And they can. But to get exceptional results, you need to actually be bulking correctly. Most beginners don’t bulk correctly.

  • Beginners don’t always have the wisdom to choose the best hypertrophy programs. One thing that’s common with beginners is wanting to take a DIY approach to building muscle. They read a few blog posts and then mix a bunch of different bulking techniques together. That can work if you know what you’re doing… but beginners don’t know what they’re doing.
  • Sometimes beginners don’t use hypertrophy programs at all. For example, they may try to bulk with a strength training program, such as StrongLifts 5×5. I don’t have anything against StrongLifts, but at its heart, it’s a strength program, not a muscle-building program. Strength training programs aren’t the same thing as hypertrophy programs.
  • Beginners don’t always understand bulking diets. For example, we see lots of beginners reducing their carb intakes as they gear into their first bulks. That’s dead backwards. You’ll build muscle more leanly by eating more carbs.
  • Beginners don’t always know how to bulk aggressively. Bulking fast isn’t about training six days per week and taking every set to failure. That won’t speed up muscle growth, it will just harm recovery. Nor is it about eating a dirty (or 100% clean) bulking diet.

In fact, it’s so common for beginners to mess up that there’s a term for it: dreamer bulking. It describes a naive bulker who thinks he’s building tons of muscle but is actually just getting fat.

I don’t mean that in a mean way. Most skinny guys have at least one dreamer bulk before they smarten up. I’ve done it twice, so I’m certainly not above it. I don’t even regret it.

In fact, most former skinny guys consider these dreamer bulks a rite of passage. We gain a bunch of muscle, a ton of strength, and, yes, a ton of fat—but we learn from it. Losing our abs for a couple of months isn’t anything to be scared of. It may even be worthwhile in the long run.

There are other ways to learn those lessons, though. One approach would be to learn those lessons from others. But if you favour a more DIY approach, that’s cool. I’ve been there. That’s a reason to bulk a bit slower. That way your mistakes won’t manifest themselves quite as flabbily.

If you’re still learning how to drive, no need to practice at 100 mph.

How Fast Can Intermediates Build Muscle?

If you’re a skinny beginner, most experts—myself included—recommend aggressive bulking. Our bodies are so primed for muscle growth that we can push our limits without much downside.

This period of rapid growth might last a few months. Maybe even a couple of years. Then you’ll hit a wall. Upping the calories will just raise your body-fat percentage higher. At that point, aggressive bulking becomes more controversial.

Once you’re an intermediate lifter, experts like Dr Helms recommend slowing down. They recommend aiming for leaner gains over a longer period of time. This is when he recommends becoming the turtle.
However, as an intermediate lifter, keep in mind that it’s much harder to gain muscle and strength. It’s easy to aim for lean gains, spend a year trying your very best, and fail to make any progress at all.

I don’t want to make this sound like a total failure. A year of maintaining your newbie gains has many benefits. You’ll have succeeded in keeping your physique in peak condition. You’ll have developed better lifestyle habits. Your natural muscularity set point may even move up. Maintaining a better physique is a worthy accomplishment. But that wasn’t your goal.

Why did your gains grind to a halt? Most—intermediate lifters hit plateaus because their hypertrophy programs aren’t good enough. Even a mediocre lifting routine can stimulate rapid muscle growth in a beginner. That won’t be enough for an intermediate lifter, though.

But it’s not just about your lifting program. One of the best ways to stimulate muscle growth is to eat in a big calorie surplus. That’s why overweight people start out so much stronger than us skinny guys. That’s why sumo wrestlers have more muscle mass than professional bodybuilders. That’s why some experts recommend aggressive bulking diets even for advanced lifters.

For example, Mike Israetel, PhD, advises advanced bodybuilders to gain a full pound per week while bulking. His argument is that it’s so hard for them to gain muscle that they need every advantage they can get—including a large calorie surplus.

In my case, I’ve always had a hard time gaining muscle and strength with smaller calorie surpluses. It’s too finicky. If I’m eating a 100-calorie surplus, there’s not a lot of wiggle room there. If I slightly underestimate my calorie intake, I risk not making any progress at all. I may even lose some progress.

During those weeks of not making any clear progress, it’s easy to rationalize away those mistakes. After all, if you’re following a good bulking program, then losing weight just means losing fat. And is losing a bit of fat really so bad?

Well, yeah, accidentally losing fat can be bad. I’ve had years go by where I’ve failed to make any lasting progress. My rate of muscle growth was so slow that it couldn’t even outpace my mistakes. A simple cold or a stressful workweek could cause me to lose a couple of pounds, undoing months of progress. For a slow bulk to work, you need to be perfect. You need to be a machine.

I’m not that way. I’m a simple Beast. Give me a short-term challenge and I’ll fight tooth and nail to win. But give me a long-term uber-precise bulking plan and I may not have the conscientiousness for it.

That’s why aggressive bulking has always resonated with me. If I make a mistake and eat a surplus of 300 instead of 500 calories, it doesn’t matter. That’s still enough calories to build muscle. Even if I mess up every other day, my bulk will succeed. A few months later, I’ll be noticeably more muscular.

Now, that isn’t to say that it’s easy. Eating that many calories is hard. I always have a hard time eating enough. But it’s simple. It’s reliable. It works.

When I bulk fast, I know that I’ll gain muscle. I know that my strength will skyrocket in the gym. And I know that I’ll be able to see those gains within a couple of months, too. That’s exciting to me.

That isn’t to say that bulking fast is better. It’s just to say that different personalities resonate better with different goals.

Intermediate Bulking: Lean vs Aggressive

Let’s plot out an intermediate aggressive bulking example. Let’s say you’re starting your bulk at 180 pounds and 12% body fat, and you’re trying to gain twenty pounds. Let’s say that you’re gaining a pound per week. And because you’re already close to your genetic potential, you’re gaining 50% muscle and 50% fat.

Start of bulk:

  • 180 pounds
  • 158.4 pounds of lean mass
  • 21.6 pounds of fat
  • 12% body fat

End of aggressive bulk:

  • 200 pounds
  • 168.4 pounds of lean mass
  • 31.6 pounds of fat
  • 15.8% body fat

Results:

  • +10 pounds of muscle
  • +10 pounds of fat
  • +3.8% body fat

Now let’s plot out an intermediate lean bulking example. Let’s say that you’re still starting out at 180 and 12%, but you gain 0.25 pounds per week. Since you’re gaining slower, your gains should be much leaner. Let’s say you gain 80% muscle and 20% fat.

End of lean bulk:

  • 185 pounds
  • 162.4 pounds of lean mass
  • 22.6 pounds of fat
  • 12.2% body fat

Results:

  • +4 pounds of muscle
  • +1 pound of fat
  • +0.2% body fat

If we imagine how these results might look, we might get something like this:

Illustration of lean gains vs bulking up fast.

Which Results Would You Prefer?

Both approaches would keep you healthy. In either case, you’re well under 20% body fat. And in either case, the quality of your training, diet, and lifestyle might be identical. No issue there.

But the lean gains guy would have better muscle definition and would be able to keep bulking. The aggressive bulker would be much bigger and stronger, but he may need to take a break.

They’ll have different challenges while bulking, too:

  • The lean bulk requires a great deal of precision. It might mean calorie counting, at least for a while. They’ll need that precise 100-calorie surplus every single day.
  • The aggressive bulk requires eating more calories. You wouldn’t need to be as exact. 300 or 700 extra calories. Both will result in tons of muscle growth. But eating those 300–700 extra calories every day is no joke. You may wind up feeling perma-full.

If you’re happy with how you look and you want to make gradual improvements, maybe lean gains are for you. Maybe you’d rather be a tortoise. Just keep in mind that you need to be precise and that it may take a long time for your results to show.

If you want to build muscle fast and a little fat doesn’t scare you, then you’ll prefer a more aggressive approach. You’re a hare. Just keep in mind that you may need to take breaks to cut when your body-fat percentage drifts too high.

Will Bulking Fast Make Us Fat?

The worry that a lot of skinny guys have is that bulking fast will make them fat. There’s a bit of a misconception here. There’s a difference between getting fatter and getting fat. It all depends on how lean you are starting out.

If you’re starting out at 10% body fat and you finish your bulk at 15% body fat, you aren’t fat. You’re still well within the healthiest and most attractive body-fat percentage range. In fact, you may even look better at 15% body fat. As we mentioned above, your neck and face will look fuller, and you’ll look buffer in clothes.

However, some skinny guys get attached to looking ripped. If you prefer being at 10% body fat year-round, I get that. Having striations in your shoulders looks badass. It’s a cool look. So there’s nothing wrong with taking it slow simply because you want to.

How to Build Muscle Fast

We have the “lean and eager” approach for skinny beginners who want to bulk up fast. For them, we recommend gaining 1–2 pounds per week for the first few weeks, then one pound per week after that. That adds up to around 30 pounds over the course of our 5-month bulking program.

We don’t recommend bulking much past 15% body-fat. That way, even if guys gain fat, they won’t harm their health or appearance. The only thing they’re risking by bulking more quickly is needing to take a break sooner than anticipated.

Bulking fast is fairly simply and doesn’t require much precision. You probably won’t need to count calories, and if you mess up here and there, it might not harm your results. It’s the approach I’ve always taken.

However, it can be hard to eat enough calories to gain weight quickly. Some skinny guys will prefer to gain weight slower simply because it’s easier on their digestive system.

How to Make Lean Gains

We also have the “soft and cautious” approach for guys who want to make lean gains. We recommend that they gain about 0.5 pounds per week during the program.

This approach requires more precision. We recommend tracking calories and aiming for a high degree of consistency. It’s more finicky. But you won’t feel as full, there’s a lower risk of gaining fat, and every day you’ll wake up looking a little bit better.

So in the end, how quickly should you gain weight while bulking? A skinny beginner who’s lean and eager to build muscle should gain 1–2 pounds per week. Everyone else should gain 0.5–1 pound per week.

If you want a bulking program to help you do that, our Bony to Beastly Program is perfect for beginners and early intermediates—for guys who haven’t gained their first 20–30 pounds of muscle or haven’t mastered the big compound lifts yet.

Or you’re at a more intermediate level, we have our Outlift Intermediate Bulking Program. It’s great for guys who already know how to lift and already know the basics of bulking, but who are starting to run into size and strength plateaus, or who want to do a better job of min-maxing their bulking routine.

Summary

For most skinny beginners and hardgainers who are eager to build muscle, it’s wise to bulk—to intentionally eat in a calorie surplus, to gain weight. Those extra nutrients open the floodgates of muscle growth, allowing us to build muscle much faster. Yes, gaining weight increases the risk of gaining fat, but with a good bulking program, that fat gain may not even be noticeable. And even if some fat gain is noticeable, it’s usually quite quick and easy to get rid of afterwards.

Illustration of a skinny hardgainer building muscle and becoming muscular (before/after).

How fast should we gain weight while bulking? That depends. Guys who are skinny-fat or nearer to their genetic muscular potential will benefit from bulking more slowly and cautiously, whereas guys who are skinny and lean will often benefit from bulking more aggressively. It also depends on how desperate you are to build muscle in a hurry.

We usually recommend that skinny guys gain around 1 pound per week while they’re still skinny, and then switch to gaining 0.5–1 pound per week as they get up to a healthier bodyweight and their newbie gains start to dry up. But for skinny-fat guys, or guys who are trying to stay as lean as possible while bulking, it’s wiser to bulk more slowly. In that case, a pace of around 0.5 pounds per week may be best.

Shane Duquette is the co-founder and creative lead of Outlift, Bony to Beastly, and Bony to Bombshell, and has a degree in design from York University in Toronto, Canada. He's personally gained sixty pounds at 11% body fat and has nine years of experience helping nearly ten thousand skinny people bulk up.

Marco Walker-Ng is the co-founder and strength coach of Outlift, Bony to Beastly, and Bony to Bombshell, and is a certified trainer (PTS) with a Bachelor's degree in Health Sciences (BHSc) from the University of Ottawa. His specialty is helping people build muscle to improve their strength and general health, with clients including college, professional, and Olympic athletes.

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26 Comments

  1. Lee on October 28, 2019 at 6:00 pm

    When referring to the older study Dr Helms mentions, what would you say explains such a difference in the fat gained?

    As it seems odd that between gaining roughly 0.5 (assumed from the study’s abstract?) pound per week vs 1 pound per week you double the fat gain without any significant increase in muscle, but between gaining 1 pound per week vs 2 pounds per week you suddenly gain more than double the muscle mass.

    • Shane Duquette on October 29, 2019 at 9:06 am

      Hey Lee, that’s a good question. Usually, researchers try to control as many variables as they can within any given study. With these bulking studies, that often means giving them a specific workout program, having them take every set to failure, and giving them some dietary guidelines. In the more expensive studies, sometimes the workouts are supervised, and sometimes the meals are provided for the participants.

      In the newer study, the participants were natural bodybuilders who were put on a hypertrophy program, all of their training was supervised, and they were given a specific diet plan. That’s a pretty good setup for producing a bunch of muscle growth. And this particular diet plan was super high in carbs, too. The tortoise group got 65% of their calories from carbs, the hare group got 75%. High-carb diets like this seem to work very well for aggressive bulks.

      The older study was done on elite athletes who were put on a dedicated hypertrophy program, and the researchers supervised one workout per week. In this study, one group was told to eat for muscle growth but wasn’t given much detail as to how. Their appetite limited their calorie intake, and so they gained weight quite slowly. The other group was put on a specific high-calorie diet plan. That high-calorie diet plan, like the new study, was quite high in carbs, moderate in protein, lower in fat. Maybe a bit lower in protein and higher in fat, though.

      In both cases, the hypertrophy programs looked solid. And in both cases, they were eating traditional bulking diets. Lots of carbs, eating fairly often, and hitting minimum protein targets.

      One thing of note is that the bodybuilders focused all of their training on muscle growth, whereas the athletes were doing just as much sports-specific training as hypertrophy training. I’m not sure if that played a role. Some sort of interference effect, perhaps. That doesn’t normally happen to such a large degree, but these are elite athletes, so maybe they pushed the athletic training harder.

      To be honest, I’m not sure what produced such different results. I mean, even within these studies, you have some participants faring far better than others. I tried to put the relevant factors in the article. I think by running through that list of factors, you’ll get an idea of how quickly you should be gaining weight. It’s not perfect, though. One of the most important things while bulking is to track your results and adjust accordingly.

  2. Lee on October 29, 2019 at 12:09 pm

    Hmm, yeah maybe the athletic training did have some effect. Yeah I guess tracking and adjusting as you go along is the best way to do it.

    You also mentioned that a reason to bulk more slowly is if you’re doing a program that emphasises the upper body. So, how much weight gain per week would you recommend for someone who has completed your main b2B program and is doing a specialist one e.g. War Chest or 8th Wonder.

    • Shane Duquette on October 29, 2019 at 10:15 pm

      Yeah, exactly. Those programs go easier on the squats and deadlifts, so I’d take a slower pace with them. We recommend gaining 0.5–1 pound per week with those programs, and if you’re trying to keep your gains as lean as possible, then err on the lower side of that.

      • Lee on October 30, 2019 at 5:47 am

        I know this depends but how much extra muscle would you assume can be gained when gaining 1 pound per week vs 0.5 pound per week?

        I ask because similar to what you mentioned above, the hare bulking aggressively then cutting was actually better off than the tortoise bulking 1 pound per week.

        • Lee on October 30, 2019 at 5:51 am

          Also I meant specifically within the context of completing those specialist programs after the main b2B program.

        • Shane Duquette on October 30, 2019 at 9:15 am

          If you’re doing everything right and you aren’t scared by the idea of gaining a bit of fat, I think you can bulk more aggressively and then cut as needed. Then, assuming you track what happens, that’s more data that we can take into account during your next bulk 🙂

          Personally, I always try to gain a good pound per week while bulking.

          • Lee on October 30, 2019 at 12:14 pm

            Sounds good. Thanks for the great advice as always!



  3. Kells on November 1, 2019 at 7:46 am

    Hey Shane! I’d consider myself a beginner with most of my muscle potential still left on the table. I work long hours for 3 days of the week and cannot work out these days. These days are consecutive (Saturday/Sunday/Monday). That leaves me 4 days of the week to workout (Tues-Fri). Without any rest days in between, what is your advice for workouts during these days? Full body workouts back to back seem exhausting and don’t leave me any rest days to grow during the week but I know I need to keep my weekly volume up especially for the main/bigger muscle groups.

    • Shane Duquette on November 9, 2019 at 9:41 am

      Hey Kells. I mean, that’s not an ideal training schedule, but not in a crippling kind of way. It shouldn’t even noticeably impact your results.

      There’s more than one way to do it. For example, though, you could train like this:

      Tuesday: Upper Body
      Wednesday: Lower Body
      Thursday: Upper Body
      Friday: Lower Body

      That would get you sweet results.

  4. Austin on November 19, 2019 at 12:01 pm

    Unfortunately, not everyone has a normal fat distribution. I was doing the bony to beastly program and eating a huge calorie surplus. I didn’t have much fat but I had some belly fat. I gained a lot of muscle in 10 weeks but I also gained quite a bit of fat. All of my fat for some reason turns into visceral belly fat. My family constantly mocked me for my new belly.

    I now plan on cutting and then going back to the program to gain more leanly.

    • Shane Duquette on November 20, 2019 at 9:03 am

      Hey Austin, when you say that you’re gaining almost entirely visceral fat while bulking, is that because you’re noticing that your belly is getting bigger underneath your abs? That’s where visceral fat is stored, true. However, that’s also where all of the extra food you’re eating is being digested. And if your bulking diet is hard on your digestion, that’s where bloat would hang out, too.

      It could be that you aren’t gaining visceral fat, you were just eating and digesting more food, maybe having a bit of trouble with the digestion part. That can make a guy look a bit pregnant until his body adapts to it.

      Gaining a disproportionate amount of visceral fat while bulking is rare because bulking also means vigorously lifting weights, which reduces visceral fat storage. With a good bulking diet and an active lifestyle, that’d be even truer. Certainly not impossible to gain a bunch of visceral fat while bulking, though, and I think your plan sounds like a wise one 🙂

  5. Lautaro on January 20, 2020 at 3:15 pm

    I think where it says “One of the best ways to stimulate muscle growth to eat in a big calorie surplus.” it should say “One of the best ways to stimulate muscle growth **is** to eat in a big calorie surplus.”

    Shane, thanks for all the articles you’ve written. They’re, in my opinion, by far the best content for skinny guys on how to build muscle in the world. From linking studies to back-up your affirmation to the nuance you introduce by explaining the contradictions in some of them; from how you sprinkle the articles with motivation on the most difficult thing (eating more) to your eloquence and clarity in explaining everything; from how you make us understand how a lot of mainstream guidelines don’t completely apply to our body types to how you explain the most nuanced questions. You even answer every single fu**ing comment that gets written.

    I cannot get tired of recommending this website and program to every skinny person I know. Thanks.

    • Shane Duquette on February 8, 2020 at 7:40 am

      Thank you so much, Lautaro! For the kind words. That really means a lot. And thank you for spotting that typo, too. I’ve fixed it 🙂

  6. Saurabh on April 6, 2020 at 2:44 pm

    Tortoise is hare in green shell, ohhh man how we missed it completely

  7. […] of weight gain depends on how skinny you are, how new to lifting you are, how lean you are, and how aggressive you want to be with your bulk. But the important thing is that you can at least some weight on the scale each […]

  8. Notaloudtosay on April 13, 2020 at 9:07 am

    Hi I’m 14 and have been working out (with wieghts) for 15 months i have an 8 pack and ok biceps and I want to gain muscle in my arms fast without making my core less cut. But my problem is I am anorexic so every time I put on some mass i get scared and shave it off the same week.

    • Shane Duquette on April 17, 2020 at 4:43 pm

      Hey man, it sounds like the root of the issue has to do with anorexia. And to be completely honest with you, I’m not sure how bulking interacts with the psychology of anorexia. I’d hate to recommend something that makes it worse. What I can say, though, is that you don’t really need to worry about getting less cut. If you gain a bit of fat, you can always lose it later on. There’s no permanent change that takes place. Most skinny guys who bulk up go through a phase of overdoing it and getting a little fluffy. I know I have. It winds up working out in the end 🙂

      I really hope you’re able to get to the bottom of this!

      • Wes Coppersmith on April 18, 2020 at 1:35 pm

        Thanks for the advice really nice of you to take time to get back to me like that nice to know there’s still good people out there. stay safe!

  9. Sam on April 28, 2020 at 12:57 pm

    Hey Shane,

    Thanks for all the work you do. I, and many others, appreciate it. I’ve been bulking for the past month or so, eating a surplus of calories and seeing steady gains on the scale. I went from 140-ish to 149 in about 4-5 weeks but haven’t moved the scale at all in the past week until this morning. Yesterday I decided to up my caloric intake from 3,000 to 3,500 calories and saw movement for the first time in a week. I suppose my metabolism has caught up to me, forcing me to eat even more than I first had to gain weight (you mentioned this might happen in one of your articles). My problem is, I feel like crap after eating so much, and don’t know if 3,500 calories is sustainable long term. I often want to throw up, and find myself hating greek yogurt and peanut butter more and more. My friend is in the same boat.

    My question is this: At what point are mass gainers OK/recommended? Can I use a mass gainer to get me those extra 500 calories? Would eating a bowl of ice cream and a slice of pie every night do the same thing? Or do I need to just buckle down and stuff in one more plate of spaghetti?

    Thanks man!!
    Sam

    • Shane Duquette on April 28, 2020 at 4:54 pm

      Hey Sam, yeah, I hear ya, the deeper you get into a bulk, the more your metabolism will rev up, and the harder it gets to eat enough calories to keep gaining weight. That’s especially true with so-called “hardgainers.” We seem to have metabolisms that adapt more readily to overfeeding. There are studies where people eat, say, a thousand extra calories per day. Some people get fat, other people adapt to it by increasing their metabolisms (largely by subconsciously moving more).

      The good news is, it doesn’t need to be sustainable, per se. You can go back to a fairly normal calorie intake afterwards. Your metabolism will gear back down as soon as you stop trying to gain weight. In fact, if your metabolism is bugging you, you can just take a break from bulking for a week or two. Eat according to your appetite. Let your metabolism settle down a bit. Just keep lifting and eating enough protein to ensure muscle maintenance. Even if you lose weight, you’ll just lose fat. And then you can go back to bulking afterwards. Best case, your metabolism has slowed down a bit. Worst case, it doesn’t, but at least you aren’t sick of overeating anymore.

      And remember, bulking doesn’t need to be sustainable. Only maintenance does. And maintenance involves eating in line with your appetite. Don’t stress about the long-term impacts of this.

      As for eating desserts or weight gainers, yep, that’s okay. Best to get around 80% of your calories from whole foods, but that’s not a hard and fast rule. And as you eat more junk food, it’s usually better to choose carb-heavy junk food. Ice cream and pie are totally fine, though (and are two of my favourites). When I was bulking with ice cream, I would often pick lower-fat ice creams, but I’m not sure that’s necessary. I was never strict about it. (Mind you, I often had to cut after bulking.)

      Weight gainers are sort of like eating a slice of cake along with some whey protein. If you prefer cake and whey protein, that’s almost as good. The only real advantage to weight gainers is that they’re made of protein powder and maltodextrin—a starch. No extra fat. Quite similar to having an extra serving of pasta or rice in that sense.

      • Sam on May 3, 2020 at 3:58 pm

        Thanks Shane, great stuff here. Makes a lot of sense! One more question, I work in landscaping 3 days a week while at school, so I find it hard to eat enough while working due to the energy expenditure. Is there any merit to bulking on my off days and maintaining on my work days? Basically, eating a calorie surplus on the days I don’t work landscaping, and eating maintenance on the days I do? Does that work?

        Also, sometimes I wonder if I should eat a caloric surplus on days that I don’t work out. If I work out 3 days a week and rest for 4, should I also be eating a caloric surplus on those 4 rest days? Is that when the majority of muscle is being built? Or on the 3 workout days? I guess I’m just curious about the science behind it all. It’s all so interesting, I can’t get enough!

        Thanks again!

        • Shane Duquette on May 5, 2020 at 11:55 am

          It’s probably good to eat in a calorie surplus for 1–2 days after training. Muscle-protein synthesis stays elevated for at least a day and often 2–3 days. If you’re training 3+ times per week, I’d just eat in a calorie surplus all week long unless you feel like you need a break from it or you aren’t able to manage it. If you can’t manage it on landscaping days, it is what it is. I wouldn’t recommend that, but if you can’t, you can’t. You’ll still make good progress overall 🙂

  10. Matthew on May 12, 2020 at 9:55 pm

    Hi! Thank you for the great articles, I have been reading all of them.

    I am a beginner (literally) and started bulking up a week ago and I feel differences already. My main issue is that I gained 4 pounds already, from which most of them are fat. I am still ok with 13% body fat, but I just wouldn’t want to overdo that. Reading your article I saw that more 600 calories surplus is not necessarily good, from which I would like to ask what would be the optimal calorie intake for an average skinny guy. I think I have been overdoing calorie consumption thats why I am getting more overall fat.

    Anyways, your articles have been so helpful and eye opening, thank you for the hard work!

    • Shane Duquette on May 13, 2020 at 9:17 am

      Hey Matthew, glad you’re liking the articles and congrats on those four pounds!

      Gaining around a pound per week works well for a lot of skinny guys when they first start bulking. To gain a pound per week, it takes a calorie surplus of roughly 500 extra calories per day. Mind you, it’s a moving target. Your metabolism will adapt. You’ll need to weigh yourself every week and adjust your calorie intake based on how much weight you’re gaining.

      If you’re gaining a disproportionate amount of fat, you could try to follow a better hypertrophy training routine, make sure that you’re eating enough protein, make sure that you’re getting enough good sleep, and make sure that you’re getting a lot of your surplus calories from carbs. But if you’re doing all of that and still gaining too much fat, then gaining weight at a slower rate should solve it 🙂

  11. […] bulking: this was me. I was incredibly skinny and incredibly eager to bulk up, so I bulked up far too quickly. It’s not necessarily that I was doing anything wrong with my training, diet, or lifestyle, I […]

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