There is a point in this article that is so IMPORTANT for you to understand that not knowing it will literally mean that you may NEVER reach your genetic potential for muscle growth.
You all know by now that I’m no fan of cardio when on bulking cycles. However, there is an additional factor related to it that I have yet to discuss.
I’ve said that doing cardio in addition to weight training is analogous to driving your car with one foot on the accelerator and one foot on the brake.
This is because the 2 types of exercise, aerobic and anerobic, work against each other IF your goal is to enlarge your muscle mass.
Read this article for an in-depth analysis.
Your personal trainer probably doesn’t know this point. His/her job is to regurgitate their text book and sell it to you (as well as push supplements that their clients don’t need).
In fact, your trainer may actually be recommending the opposite of what I’m going to say and thereby hinder your progress!
Here we go…
Muscle growth is basically making your individual muscle fibers thicker. Think of them like long strands of hair running parallel to each other. Make those individual ‘hairs’ thicker and your overall muscle size increases.
However, it is the Type 2, fast-twitch, fibers that are responsible for growth.
Here’s the interesting point…
The body will change the functional characteristics of one type of fiber to another depending on the nature of the training stress. That’s great news!
This basically means MORE potential for actual muscle growth!
How do we achieve this?
Short, intense, ANAEROBIC weight lifting will signal to the body that it needs to adapt by converting some type 1 fibers into those more resembling type 2 fibers i.e. they become more anaerobic.
But also, our intermediate fibers (2a) can and will become 2b fibers which is more desirable for bodybuilders.
But you can screw this up royally. How?
If, at the same time, you perform a lot of low intensity AEROBIC work, you send the opposite signal. You are saying, “Wait, hold on to those type 1 fibers, I need them for all this aerobic work I’m doing.”
In fact, do this enough and you’ll actually make your muscle-building type 2 fibers more aerobic in character/function. Not good.
So the body is adapting to the predominant signal you are sending it.
Since the body has FINITE resources, you need to make the most of what you’ve got.
I can’t tell you the amount of times that people complain that they are getting nowhere with their training even though they are “busting their ass”. Of course, “busting their ass” means going to the gym and doing A LOT of work in the form of weight lifting AND cardio in an attempt to build muscle and lose some fat.
“A LOT” of work is not necessary for muscle growth. The right TYPE of training stimulates growth. Furthermore, they work against themselves by sending 2 opposing signals to the body in terms of how it should adapt!
Some of them don’t believe me when I tell them to drop the cardio, do less sets, but INCREASE the intensity of those sets. Oh well, maybe I’ll see them in 5 years time when they still haven’t achieved their goals and are ready to get real.
Now, are you a hardgainer?
If so, this is particularly relevant to you! Why?
Because you don’t have a large complement of type 2 fibers to begin with.
Your body has finite resources and you should send one signal and one signal only: Make my type 2b fibers BIGGER and make my 1 and 2a fibers more anerobic so that I can MAXIMIZE my genetic potential for growth. (There’s also the beneficial conversion of type 2x to 2a but that’s beyond the scope of this article.)
How do we do this? Ditch the cardio and train THT style.
I can almost hear someone out there say, “But I know someone who does both and is big”. In that case, you need an understanding of bodybuilding genetics. A small percentage of people have genetic advantages that will allow them to succeed even when working against themselves. Accept it and get on with it.
I wasn’t blessed with great genetics either. Some people will always be bigger than I am. But I have managed to make the best of what I have by training intelligently; by training in harmony with how the human body actually works.
Even those genetic freaks would have gained even better by sending one ANAEROBIC signal.
The point is this: You can get bigger and CONTINUE to get bigger by sending one clear signal of growth to the body.
Hit the body with short, intense workouts. Rest. Recover. Grow. Repeat. Done!
Does this mean that you won’t get fitter? Absolutely not! This is another dumb assertion by some in the fitness industry. I recommend you read my article which includes a section on how intense ANAEROBIC work DOES make you fitter in general.
Does this mean that you should move as little as possible? No, not at all. Live your life, walk your dog, fix things, move things, and so on.
Just try to limit aerobic work that will leave you seriously out of breath, or cause you to “feel the burn” in between intense workouts when you should be resting and recovering.
When you want to aggressively cut fat, do your cardio.
More Intensity + Less Volume + Less Aerobics = More continuous muscle growth.
So train hard and then relax! Talk to you soon,
Can I give you my free muscle-building workout?
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Great stuff. I was unaware of this fiber conversion. I am an ectomorph. I only do about 15 mins of cardio about 3 times a week, but since I don’t need to lose any fat I don’t know why I do it, I just always have I guess.
But I’m going to try dropping it on your recommendation. Thanks.
I’ll agree with this 100%. I only get cardio if I play ball hockey at the office during the week (rarely these days) and my once-weekly ice hockey games.
Other than that, zip, nada, nothing – and I can keep up with the guys who play 3 times weekly (ball hockey), more than once weekly at ice hockey AND some also do other cardio.
Great article Mark!
Mark, I have to disagree with some of your comments. You cannot turn a type I fiber into a type II, or vice versa. You can only make type II fibers more white, or more red by forcing them to add mitochondria.
The fiber itself does not get smaller as a result of its mitochondrial density. The reason people who engage in a lot of cardio typically have smaller muscle size is that they often exhaust their intramuscular glucose supplies, and force their muscles to engage in neoglucogenesis (a fancy term for how the body converts protein to glucose). Doing this habitually, combined with heavy lifting, means the body will be breaking a lot of protein down to power a workout. To counter act this, the body would need even higher levels of protein intake, as well as sufficient carb intake to keep.
After all, if it was about muscle fiber type only, the law of specificity would suggest that you could still get huge on top, but just have skinny legs (hamstrings in particular). Most long distance runners (esp the pros) have pretty big hamstrings and gluts, in fact. And the Tour de France guys have giant quads, despite spending hours upon hours on the bike. It’s just that these guys are small on top.The reason is that their body keeps stealing the protein for the neoglucogenesis from muscle that is the least active, which for runners and cyclists is their upper body.
Your body can only replenish glucose stores at a certain rate, however, so I think there is a limit to how much you can mix heavy lifting with heavy aerobics, but I do think its possible. Personally, I added close to 10 lbs of muscle and added strength in every body part that I train while training for a marathon last year. I was hawkish in terms of the amount of protein (esp glutamine) that I consumed, as well as consuming extra mid cycle carbs to help keep glucose demands met. So it’s doable, though more difficult to get right.
Is this correct as I understand it:
High intensity interval training (HIIT) is still cardio, and is best avoided if your goal is to build muscle?
By the way, Total Anabolism is a killer routine. Wish I had started sooner. Thanks for all of it.
I train THT style for 3 weeks know, no cardio at all EXCEPT the half-hour bike ride to work and back every day. Does it hinder me in any way? I prefer the bike to public transport 🙂
David yes you can, and theres still one kind of fiber called IIX that can convert to the fiber you are needing most.
Mike this is for you, I am doing all my work out with only 10 seconds of tension and concentric and eccentric as fast as I can. I am having the best gains of my life. I started to try this at first because with more than 10 seconds, when with maximal velocity, the type IIb (the ones that get most hypertrofied) are fadigated. Since F = m. a. I am recruiting the maximal fibers that I can. About the eccentric Ive been reading some studies that show that when the eccentric is like 1 second or less it gives more hypertrophy, its hypotetizated that eccentric fase works forward concentric when talking about fiber activation.
The bad is that this kind of training may be easier to get a lesion.
Well, just my thoughts about. If you wanna try, its working a lot for me.
btw: better results than with THT.
if you wanna talk feel free to mail me, I can send some studies to show scientific proof of what Im saying.
I mean scientific arguments.
@Tim and Adam. Thanks.
@David. I would say the reason runners are thin isn’t because of gluconeogenesis, after all they do carb-load to provide an abundance of glucose prior to running. They are thin because of the frequent, aerobic activity they engage in. They simply can’t build any muscle with that type of training.
The main reason why I am saying you can’t do both effectively isn’t because you can “only replenish glucose stores at a certain rate” as you say, it’s because sufficient rest and recovery must take place between training stresses to allow for not only full recovery, but overcompensation as well. It is important to remember that a muscle stops recovering when it’s worked. This is why I am stressing intense, anaerobic workouts followed by a cessation in training (aerobic or otherwise) for those who wish to train specifically for hypertrophy.
Regarding fiber conversion. Yes, what you are saying is correct in that 1 fiber type takes on the functional characteristics of another type depending upon the type of training stress. True.
But also, our intermediate fibers (2a) can and will become 2b fibers which is more desirable for bodybuilders. As Bernardo says, there’s the 2x which can become either 2a or 2b depending on what sort of adaptations you force the body to make.
I’d also like to include the following which I have copied and pasted so that I don’t have to type it out again…
“Our subjects were very elite sprinters, whom we studied during a three-month period in which they combined heavy resistance training with short-interval running. At around the same time, Mona Esbornsson and her CO-workers at the Karolinska Institute in Stockholm reported similar findings in a study involving a dozen subjects who were not elite athletes. These results suggest that a program of vigorous weight training supplemented with other forms of anaerobic exercise converts not only type 2x fibers to 2a but also type 1 fibers to 2a.”
@Jim. Yes that’s correct. Leave it until you want to go on a cutting cycle.
@Andrew. I’m sure it’s fine. I imagine that would be a fairly relaxed pace?
@Bernardo. You can send me it by the contact form.
It’s true that you can cause type IIa to become IIb, and vice versa, but lifting in the 8-12 rep range as you advocate turns IIb into IIa, not the other way around. That’s because any set lasting over 30 seconds needs oxygen to continue. Oxygen is used by mitochondria, which give a muscle fiber it’s color (or lack thereof). Type IIb is the power lifter’s fiber; Type IIa is the body builder’s.
Also, it takes up to 48 hours to replenish intramuscular glycogen stores through feeding. That’s why marathoner’s don’t do any running the 4 days prior to a marathon, to not only replenish their stores, but to allow ample time for supercompensation. For the average hardcore long distance runner, they run 5 or 6 days a week. That leaves no real time to ever fully refill their glycogen. In addition, the whole point of the long distance run is to exhaust the body of it’s glycogen stores completely, in order to train it to conserve better the next time around. Those runs, repeated over the course of months, or years, is what leads to upper body muscle loss. This is why colds are so common amongst runners, as all the neoglucogenisis depletes the body of glutamine stores, and glutamine is one of the primary fuel sources for your immune system.
Leaving that aside, you still haven’t explained why the law of specificity of training prevents someone from getting absolutely ripped upper bodywise, while only suffering stagnation in their legs. You also haven’t explained why speed skaters, or hockey players, or Tour de France cyclists have quads that look like they would be at home on a thoroughbred.
Overtraining is one point where you are right, it could be easy to overtrain your legs if you do a lot of aerobics ontop of a leg lifting workout. Like I said though, it’s all about being very precise in how you train and how you eat.
I would also add that technically, you can’t change any fiber type to another permanently. If you stop providing stimulus, the reddest type IIb fiber will go back to white, a white type IIa will go back to pink, etc. And type II fibers will always flouresce differntly under UV than a type I no matter how much long distance running you do. It’s a lot like tanning in that way, you can add melanin to skin cells, causing it to darken, but no matter how long you’ve lived in Souther California, if you move to Alaska, you’ll be white as a ghost in 6 months.
Hi David I would be interested in getting to know more about the way you train so that I could try it too and see what the results would be. I cannot see your email address anywhere though. If you can see mine I would appreciate on knowing exactly how to do the type of training you do in layman terms 🙂 Oh I would also like to know over what period of time did you gain the 10lbs of muscle you referred to in an earlier post?
Hey Mark I have looked into your website and I am thinking about starting the volume cycle. I was wonering what kind of warmup to do before jumping into the working sets?
C’mon man, don’t bag on trainers, not all of us are clueless.
Yes I recommend the tried and tested 8-12 rep range. In the book and on the site I also recommend a cadence of 1 sec positive and 1-2 sec negative for this rep range, which comes to 24-36 seconds per set at the most.
This will recruit those 2b fibers and since muscle fibers are recruited sequentially, will recruit all the others as well. This is desirable for us who train specifically (and only) to make our muscles larger (and stronger in the process).
Glycogen can be replenished within 24 hours and you’d only go longer to overcompensate. But I’m not sure why you bring up runners. You say “In addition, the whole point of the long distance run is to exhaust the body of it’s glycogen stores completely, in order to train it to conserve better the next time around.” I understand that but my site is about specifically training for muscle size. We couldn’t care less how runners should train.
You also say that, “Those runs, repeated over the course of months, or years, is what leads to upper body muscle loss.” Yes, extensive running is catabolic and for that reason hypertrophy trainers should stay away from it, that’s the point. When you change the goal e.g. the bodybuilder wants to prioritize fat loss for 6 weeks or so, the training changes to accomodate cardio, and his/her nutritional strategy must also change too.
I talk about the law of specificity in my free book: a certain way of training produces a certain adaptation. Therefore THT is designed specifically for maximal hypertrophy. What does added cardio have to do with that goal? Nothing. So I recommend you don’t waste your time doing it. Can someone be ripped and have large legs? Of course. In fact I have produced just such a result in many clients. I’m not sure what your point is there.
As far as cyclists with large legs goes, I’ve never seen one personally. But is it possible for someone with the right genetics to build fairly large quads by cycling? Sure. Most people won’t however, and those that do will wait many many years to see such a result. It would be a terribly inefficient mode of training if your goal was to get larger legs. Again, it’s all about specificity. My readers are here to grow, and grow only. Why would I recommend cycling to them?
The catabolic nature of a high intensity weight training session demands at the very least 36 hours for recovery. Since we want to overcompensate and get larger, the average trainee needs to rest as much as possible between training stresses. As I said in the above article, low intensity aerobic activity won’t interfere with the recovery and growth process, so you don’t need to sit on the couch all day. But intense cardio is counterproductive for the bodybuilder since mechanical work by the muscles is mechanical work by the muscles, whether it’s on a stationary bike or doing some squats. The relevence? A muscle stops recovering when you work it. For growth-seekers then, the ideal situtation is to stimualte growth with intense lifting, then to rest. Then repeat. Any additional work doesn’t help but actually hinders the process i.e. you overtrain. The recovery process in terms of muscle growth is not the same as for runners; there is more to it than glycogen. A good book on this is “Body by Science” by Dr. Doug McGuff. He is totally against cardio for many reasons that I don’t have the time to go into here. I wrote an article that includes many of his points that I linked to in the above article.
In terms of the fiber-change adaptations not being permanent, that’s true, but no adaptations are permanent. Whether it’s larger muscles that a bodybuilder produces, or more mitochondria as the runner produces, it’s all impermanent. A quote from my free book, “Any adaptation can return to a genetically determined, pre-training state if the stress is not maintained or developed properly.”
Perhaps you’re framing this article in the wrong context. This applies only to those whose goal is only to enlarge their muscle size as quickly and efficiently as possible. That’s not to say that those who engage in cycling and so on can’t build muscle. They can. But they won’t build it as quickly or to the degree that a bodybuilder will. Bodybuilders should do what I recommend above, except for when they are prioritizing fat loss as their goal (which is only once a year for most).
On the volume cycle do a light set of the first working set before the workout. For example, on shoulders day, do a set of overhead presses with 50% of the first working set weight for 10-12 reps. You can do some low-intensity aerobic work for a couple minutes. No stretching, it can temporarily weaken a muscle.
Point taken my man. 😉