The Mountain Dog Guide to Cardio

by on March 1, 2014

March 2014: The Mountain Dog Guide to Cardio

Doing “cardio” is one of those topics that everyone has a different opinion on and no one really agrees. For the competitive physique athlete, the opinions on it will range from some preaching that it MUST be done to get truly shredded, to others who avoid it all costs.

In my personal experience, cardio is the most poorly understood and abused practice in all of bodybuilding. From doing too much, too little, to the wrong kind or not enough of the right kind, many many physiques have been ruined come contest day, and likely even muscular potential cut short because of excessive cardio.

Done properly, cardio can enable continuous and steady fat loss while helping to facilitate proper recovery from training. Done improperly, it can quite literally break down muscle and leave someone’s physique soft and depleted.

To truly understand cardio from a bodybuilding perspective, we have to create a larger context from both a practical and scientific standpoint. This is not to over complicate, but so that we have the knowledge to really analyze and make a smart decision on when and how we should be using it.

To start, lets look at the straightforward technical definition of “cardio.”

Aerobic Exercise (cardio) is a broad term that refers performing physical activity that focuses on minimally to maximally elevating heart rate. This type of activity is fueled almost entirely by metabolism of the oxygen you breath, and only at higher rate levels (intensity) will the “anaerobic” systems kick in. The anaerobic system consist of three subsystems; glycolysis, the Krebs Cycle, and Oxidative Phosphorylation.

Without turning this into a chemistry lesson, all three of these systems produce ATP, Adenosine Triphosphate, which is the primary source of energy used by muscle cells for higher threshold contracts. Said simply, these are the systems you use when lifting weights, and their waste byproducts are what is partially responsible for the burn and pump sensation while training.

What is important to understand still though, is that even during weight lifting, your body is still using oxygen. Both the aerobic systems and the anaerobic systems operate concurrently with one another, but depending on the activity one will dominate over the other.

One last piece of knowledge on cardio before we move forward, is understanding the term “intensity”. When lifting weights, intensity refers to the percentage of your one rep maximal weight repetition, commonly known as 1RM.

Intensity then for cardiovascular training refers to heart rate elevation, and your heart rate relative to your maximal heart rate, which is coincidentally expressed as % of MHR. Just as you would not readily test a true One rep max in the gym, you would also not want to test your true Maximum heart rate unless under controlled conditions.

Now that we an understanding of the differences in “cardio” and what intensity is, lets begin to link this together into the context of actually lifting weights and building muscle, and that entails explain the Central Nervous System, the CNS.

CNS/The Light Side vs the Dark Side

The Central Nervous system can be conceptually understood as a battery, which in this case is your brain. Your CNS is what sends the signals for your muscles to contract and move. Your battery has two parts to it, the Parasympathetic Nervous System, and the Sympathetic Nervous System. These two systems have different responsibilities and activities that they “power” so speak. And like any battery, they can become drained with usage, and need to recharge.

Also, just like the cardiovascular system, they BOTH work together at the same time, but which predominates again depends on the activity.

So which system does which?

The Parasympathetic Nervous System can be thought of as the “low voltage” system, in that it powers the body when it is at rest. So walking, basic non athletic moving around, that’s the PNS predominately system working. It also powers the organs and glandular systems. It is referred to colloquially as the “rest and digest” system. Because it is responsible for so many daily, unconscious functions of your overall metabolism, its “reservoir” of power is much higher than that of the Sympathetic Nervous system. Inversely though, its actual output of “voltage” is lower.

The Sympathetic nervous system then is the “high voltage” system, and is responsible for the flight or flight response. And much like the PNS, it manages the internal organs, BUT it has a far greater effect on the Adrenal system than the PNS does. Your adrenal system is what releases adrenaline, epinephrine, and norepinephrine into the bloodstream. These are the hormones that you should recognize as getting you excited, fired up, and in the case of norepinephrine, actually help metabolize bodyfat (more on that later though). The Sympathetic nervous system really “powers on” then when the body is under stress and charged up to move. So when you take deep breaths get tight before a high rep set of squats, your SNS is doing most of the work in sending the signals to your muscles and keeping your breathing steady. Similarly, lifting heavy weights is usually considered an SNS activity, unless we are talking about extremely light, low stress movements.

So why do we need to know this?

Because the power of your battery is finite, it has a limit, and it can only put power towards so many things before its drains out and your performance declines. And while it damned near impossible to “burn out” your CNS, you can over tax it enough that it makes it impossible to adequately adapt to the stress you are placing on it.

So now that we understand the CNS, lets incorporate that into one final perspective, the SAID Principle.

The Doomsday Principle/SAID

SAID = Specific Adaptation to Imposed Demands

This principle states that our bodies will specifically adapt to the demands that we place on it. We will adapt to these demands so we can better handle them the next time we do them. Broken down even further, we will get better at handling the same stress if we do enough of it, so it become LESS stressful.

And that is the key point; all of our adaptations take place because our body DOES NOT WANT TO BE stressed out. We get stronger so the stress becomes easier to handle.

So with all of that put into context, how does this all tie into BUILDING MUSCLE?

Well, we using our SNS system to lift, we are recharging while our PNS facilitates our recovery, and our lifting is a fairly even mix of the aerobic and anaerobic systems. Especially if we are training using Mountain Dog Methodology, we are actually getting in a fairly large amount of aerobic work. So during high rep leg presses and squats, drop set lateral raises, and giant sets for arms, our cardio is being worked.

And remember, lifting weights is what we are adapting to specifically. Our body adds muscle so that lifting is less stressful. We get stronger then, and lift more and heavier weight to keep it adapting. Through all this our SNS is powered much of the lifting, our cardiovascular system is receiving an even mix of both stress, and we are growing.

What’s our big takeaway from all of this?

While we are lifting, we ARE working our cardiovascular energy systems mainly. And that we WANT our body to always keep growing more and more muscle, so lifting then is our primary activity.

So that finally brings us to our big question:


Depending on how you train, YOU DON’T.

How so, you are probably asking? This is WHY.

Assuming that your training is of greater enough cumulative intensity across working the SNS, working your aerobic systems, and breaking down and rebuilding muscle tissue, then you are ALREADY doing everything you need to be doing to build muscle.

Doing additional cardio will only create an additional STRESS upon your CNS. Even if it doesn’t feel tiring, it’s not going to facilitate increased muscle growth.

HOWEVER, if the cardio you do is of low enough intensity that it doesn’t require much adaptation to, THEN it can be excellent to do, and can actually increase recovery by stimulating your PNS.

What kind of cardio is this?


Walking is a very low stress PNS dominant activity that any bodybuilder can do to metabolize additional calories WHILE not stressing out their recovery capabilities or interfering with their SNS. Remember that we want to adapt to building muscle and building muscle only. Our cardiovascular capacity is directly relative to our ability to train and train hard then.

So is the solution then to NEVER do cardio?

No it is not, but it MUST be done with in the appropriate premise, which in the case of the Bodybuilder, is burning bodyfat and being made of shred.

So consider the following premise:

If it is competition season, and I am dieting for a show, do I WANT to being a high volume of aerobic and cardio?

No, BUT why not?

Because as soon as that quantative volume of that cardio begins to equal that of my lifting, my body will be split to adapting to two different activities, which essentially have the opposite adaptive responses.

Particularly noteworthy is the signaling pathways within muscle cells that stimulate hypertrophy, such as mTor/AMPK and IGF-1, are actually inhibited when slow aerobic training is done in conjunction with resistance training. Why is this? Because from an adaptive response standpoint, the same muscle and same pathways are being doubly stimulated with two different stresses, and will NOT optimally adapt to either of them.

So we may be actually stopping muscles from growing if we subject them to too much of an opposing stimulus. And this gets even worse if we starting adapting too much to the Aerobic Cardio.

Adaptive response to Aerobic Cardio

  • Increased efficiency at specific activity (let’s say the stepmill)
  • Reduction in overall energetic output at said activity
  • Reduction in overall metabolism/output of calories
  • Elimination of tissues that decrease efficiency of said activity
  • Reduction of lean body mass

Yep, you start losing your gainz as they say in social media land, and it is way too common.

What’s worse than too much slow cardio then? Too much Anaerobic Cardio! The HIIT monster.

So let’s assume you also want to burn bodyfat, so you decide to do HIIT.

Now here is the issue. High Intensity Interval training is NOT powered by the PNS, it is powered by the SNS. Because it predominantly anaerobic, it depletes ATP and Glycogen, and taxes that same energy systems that we use for lifting weights.

Additionally, because it is SNS dominant and energy intensive, it drains our SNS and PNS at the same time. So it is actually one of the most intense stresses you can expose yourself too.

Because of this, doing more than 2-3 sessions a week is not really advisable, and practically even one session can be more than enough.

And you might be thinking “but it burns bodyfat”. And according to the literature, it does, but the AMOUNT of fat it burns also comes with a very metabolic cost in regards to both localized muscular recovery and CNS recovery. Because of its overall CNS cost, it can only be done sparingly, otherwise its cumulative effect will begin to mirror that of slow aerobic cardio, in that the body will adapt to become more efficient at it. And by more efficient, I mean the reduction of muscle mass.

From personal experience, I have seen competitors with very nice physiques absolutely eat away at their legs from doing too much HIIT, especially on a stepmill. Trying to do HIIT past even 3 times a week is one of the most frighteningly effective ways to burn off muscle, and I personally wouldn’t recommend it more than twice weekly if you are going to do it.

Depending on the modality of HIIT you decide upon, it can potentially stimulate hypertrophy. So activities such as sled pushing or sprints could be worthwhile, provided these activities are not being doubled up with leg day.

So for someone that is a physique athlete and NOT a bodybuilder, it can certainly be factored into a program. This does not mean do it EVERY day, but it can be a worthwhile strategy within a program.

For pure bodybuilders though, I would consider HIIT an adjunctive TACTIC to burn off additional fat, but it is poor long term strategy, as it would likely come at the cost of muscle mass.

So how does Mountain Dog programming incorporate cardio?

  1. Before you even think about cardio, get your recovery working perfectly, and build your weight training sessions up FIRST.
  2. If you decide you need to add cardio, and your calories are still high, and energy is still high, HIIT sessions can work very well. Still we keep most people to 2-3 sessions per week.
  3. As you get closer to a contest and get leaner and leaner you might not feel like a superhero all day long. Your weight workouts will be good due to intraworkout nutrition, but other times of the day you may feel like doggie doo. It comes with the territory, Getting to an unnatural state of bodyfat “hurts”. If it didn’t we would probably all be shredded. So as you get more tired, etc, switch over to walking so your CNS isn’t further drained.
  4. Don’t be afraid to change modalities. Do some swimming, do some elliptical, do some walking etc, depending on which type you are employing. Vary it.
  5. Once you are at 95% of your target condition, stop. Your body will keep burning fat for a bit. You don’t want to be doing cardio after you hit peak condition or you will do nothing but deplete muscle.

Thanks for reading! Please send questions about this to Alexander and John!

Alexander Cortes and John Meadows