By day, I'm a skeletal muscle physiologist in a laboratory at the University of Tampa. But I also have a secret—OK, it's no secret. I absolutely love bodybuilding and lifting weights. Ever since I was a kid, I knew I wanted to be a scientist studying sports performance, and bodybuilding in particular.
To me, bodybuilding is fascinating because it's based on the ultimate dichotomy: gaining size and getting shredded at the same time. These shouldn't mix, right? But they do, as we see in our lab on a regular basis.
At any given time, we're doing approximately six experiments on bodybuilding. We can look at muscle from the bone to the skin; we can scan your whole body and tell you the most accurate ways to look at fat. You name it, we can analyze it.
I want to bring this sport to a new level with the latest science has to offer, and I want you to ride along with me.
Pull up a chair and get out your notebook. Mass Class is about to begin.
Jacob Wilson Training
Watch The Video - 12:10
Question 1 What Makes Muscle Grow?
If you look at all the scientific literature, you'll see we've narrowed down how muscle grows to at least 3-4 different mechanisms. You'll hear people say, "Oh, so-and-so is the best training method," but that method might only maximize one of those mechanisms. When you're training for maximum growth, periodize your training so you can optimize each of these mechanisms.
Luckily, there are many different techniques you can use to do this.
Different researchers have different ways of categorizing them, but here's what I consider the primary mechanisms of muscle growth:
1 Cell Swelling
You've probably heard guys who are about to go to the gym say things like, "I'm gonna go get my swole on." There is actually something to what they're saying. We call it the cell swelling theory.
When you train and you get a pump, kind of like Arnold famously talked about in "Pumping Iron," your muscle cells sense that swelling as a threat. They basically say, "OK, I have to grow or die." So they restructure themselves and get larger.
What are the methods to increase that edema, or that blood to the muscle? Working in the hypertrophy range of 8-12 repetitions is one, especially with short rest period lengths.
2 Mechanical Tension
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If you're looking to build muscle that's as strong as it looks, focusing on cell swelling isn't enough. You also need to amplify the tension, which is how you recruit the larger and more powerful muscle fibers.
You may have heard that we have slow-twitch muscle fibers, which are good for endurance, and then we have the larger fast-twitch muscle fibers. Those get recruited with heavier lifting, like during sets of 6-8 repetitions or less. When you recruit them, they turn on protein synthesis and you grow.
Of course, if you are lifting with short rest periods, you can't lift as heavy, so the mechanical stress is less. So during your heavy days, rest 3-5 minutes in order to maximize the mechanical load.
That repetition range could still be around 6-8 reps—I'm not talking about power lifting, after all—but you'll rest longer so that you can lift heavy every set.
3 Mechanical Trauma
Mechanical trauma, also known as muscle damage, occurs when you lower a weight or hit the eccentric portion of the lift hard. It can happen when you do things like forced reps or negative reps, as well as during heavy lifting—think the bottom of a squat. This is when you focus in on destroying the muscle.
You've probably heard about how when you train for hypertrophy, you create "micro tears" and tiny abrasions in your muscles, and that the recovery from these small injuries is how muscle grows. This is true, but it's not the only way to train for growth.
Training with an emphasis on muscle damage and working to failure is definitely effective, but like anything, it can also be overdone. Use it as one of several tools in a balanced program, and you'll maximize the benefit you receive from it.
4 Metabolic Stress
Everyone knows that burning sensation you get when you're training. That is metabolic stress, which is another name for acid building up in the muscle.
One of my colleagues, Dr. David Gundermann, took the novel step of isolating muscle cells putting them in lactic acid. Guess what? They grew! The mechanism that causes that burning sensation can actually make muscle grow. This is one reason to keep your rest periods short on a hypertrophy day.
If you rest for five minutes, talking about what you did over the weekend, that clears all out that metabolic stress.
This is part of the reasoning behind keeping rest periods short, like 60 seconds or less, or occasionally removing them altogether and doing supersets or strip sets.
Question 2 What am I doing wrong?
I think the biggest mistake people make is underestimating their capabilities. They limit themselves mentally, and that leads to limiting themselves physically.
For example, I can't tell you how many times I hear or read things like, "Oh my God, I'm going to overtrain, so I can only train everything once a week." However, studies are showing that the more frequently you train, the better your gains will be. Sometimes when you have an overload on the muscle every day your performance is not going to be the best, but you are beating the muscle up so much, it has no choice but to grow.
There are new studies coming out by some of my colleagues in Finland and Norway where they show incredible gains from weightlifters who change from three days per week of training to six days per week of training per body part.
That's an advanced technique that isn't appropriate for everyone, but the larger point is this: Don't limit yourself. The human body can withstand a lot more than you think, so long as your nutrition and sleep are in place.
Question 3 Compound or Isolation?
- Squat variations
- Deadlift variations
- Leg press
- Bench presses
- Overhead presses
- Pull-ups and pull-downs
- Rowing variations
- Triceps kickbacks
- Biceps curl variations
- Cable cross
- Skull crushers
- Leg extensions
- Leg curls
- Most machine exercises
- Calf raises
- Shoulder raises
When the goal is mass and creating the most anabolism (protein synthesis), compound movements that hit muscle groups should always be the center of a bodybuilding program. That's going to be things like squats, bench presses, and leg presses.
But make no mistake; there is a difference between bodybuilding and powerlifting. Namely, bodybuilding is about making exercises harder. You're trying to beat your muscles up. If you're doing a bench press and you're bodybuilding, your back might be flat, you'll focus on the muscle, and on every aspect of the lift. If you are a powerlifter, you're going to get an arch in your back, shorten the range of motion, and use more leg drive.
The same thing applies with squatting. In powerlifting, your goal is to get the weight up, and you can take steps to make that easier: changing your stance, or using the belt for support, for instance. But in bodybuilding you're focusing on destroying the muscle. So you'll see lifters use dropsets, pre-exhaustion, and other overload techniques.
Once you have your compound movements in place, however, bodybuilding is also a sport of symmetry. This is where isolation movements come in. Use them as tools, but not as the foundation.
A lifter who does all isolation and no compound movements is going to be light years behind one with a more balanced program.
Question 4 What's the best cardio for bodybuilders?
As I mentioned earlier, one of the fundamental dichotomies of bodybuilding is to gain size and lose fat at the same time. To gain size you lift weights, and to lose fat you do cardio. Simple enough, right? Yes, except that plenty of bodybuilders do hours of cardio every day, an amount on par with high-level endurance athletes.
But look at a marathon runner. Is that something a bodybuilder aspires to be? Clearly not. What we found in our laboratory is that the longer you do cardio, the more muscle you lose. Why would you spend all this time in the off-season gaining muscle, if you're only going to lose a lot of it with long-duration cardio? This is exactly the problem we've been trying to solve.
The answer is high-intensity interval training, or HIIT, as it's often known. When I say high intensity, I'm talking about 10-30 seconds of all-out, balls-to-the-wall sprinting. If you do it for 10 seconds, you should have nothing left at the end. After 30 seconds of work, you should feel like you're going to die.
Sounds miserable, right? But you'd better believe it's effective. We found that in just 10 seconds of this type of training, you can deplete your muscle energy stores by approximately 15 percent. That might take 60 minutes to achieve with traditional cardio. What that does is send a massive signal to your body saying, "Oh my God, I have to increase my fat burning machinery." When you do that, you burn fat the rest of the day.
The results are truly remarkable. We've found that with 10-30 seconds of all-out sprints, you can actually lose more fat in just a few minutes than with the long duration 30-60 minute cardio—and you maintain your size. We did a study in our lab where we compared low-intensity cardio to high-intensity cardio side by side, and not only did the sprinters lose more fat, they even gained muscle in their quads. So sprinting can even be anabolic!
Question 5 How do I avoid injury?
Say you're someone who responds well to heavy training. Every time you to go the gym, all you do is lift with eight or fewer repetitions per set, heavy weights, and with long rest periods. You're constantly loading the muscle, and that's where it can take a toll on your joints and ligaments. Eventually, you feel the strain, and you get an injury.
Sample Periodization for Muscle Growth
- Workout 1: Hypertrophy, 8-12 reps per set, < 60 sec. rest
- Workout 2: Heavy lifting, 6-8 reps per set, > 3 min. rest
- Workout 3: Hypertrophy, 8-12 reps per set, focus on supersets and dropsets
- Workout 4: Occlusion training, 15-30 reps per set, < 30 sec. rest
For a competitive bodybuilder, this is the worst thing ever. If you're out for a month, you lose muscle, and then it takes you a month to recover. You just lost two months—and that's being conservative.
Periodization is programmed change, and it's one of the keys to avoiding injuries in the gym. Here's how it works: One day each week, you could perform traditional hypertrophy training, which can be 8-12 reps, 30-60 second rests. One day you might train heavy, in a 6-8 repetition range, with longer rests. Another day, you could do a hypertrophy superset day. Then, if you feel like your joints are hurting, you could try a new technique known as blood flow restriction training, or occlusion training.
This technique, what happens is if you restrict blood flow to a limb, you only have to lift at like 30-40 percent of your maximum weight and you actually can grow.
Simply put: Focus on the goal, and balance your training styles. Give your joints and muscles programmed rest periods, and you recover—and keep growing.
Question 6 How can I be more scientific with my training?
Bodybuilding is like any other sport. To improve at it, you have to master your trade, which is lifting weights.
Get everything you can out of every single lift. If you are doing a set of 12, every single rep should count. We know from plenty of studies that when people focus on the muscle, they activate more of it. Going through the motions, on the other hand, is only going to give you pedestrian results.
Success in this sport is all about focus. Make everything count. Make every meal count, make your sleep count, make every rep count, make every set count. Be meticulous. Write down how you felt in the gym. Write down what you are going to do, and what you want to be.
Set goals that are attainable, and stay abreast of the latest research into those goals, and you'll keep moving toward your ideal physique.