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Knowing Your Cardio


This past winter I had the opportunity to watch a local bodybuilder preparing for a national contest. Although the gym I train at has a cardio theatre (with surround sound) and another cardio area complete with flat screen televisions, it also has a third cardio area vaguely attached to the rubberfloored room set aside for Olympic lifting and kett lebell training – the room I spend 90% of my time in.

In between my split snatches and hang cleans, I watched this bodybuilder’s daily cardiovascular routine. He was walking for an hour at lunchtime, which I discovered was one of his two daily sessions. By contest day, he lost virtually all of his bodyfat and looked phenomenal – for a few hours. 

This article isn’t for guys like him. It’s not for people who want to be ripped on one day out of 365. I don’t care about the people who train to be in awesome shape for four hours, but require four months to do it. I’d much rather turn that around – I’d rather be in shape for four months (the summer) and train four hours per week to get there.

First a Little Math

At the speed my bodybuilder friend was walking, he was burning roughly 300 calories every hour. Had he been jogging slowly, he’d have burned those same calories in half as much time. Jogging at a fast pace would have cut about ten additional minutes off his cardio time (bringing him to a 20-minute session). Bluntly speaking, he was squeezing 20 minutes of work into 60.

In an effort to “save muscle” on his pre-contest diet, he was advised to keep the intensity as low as possible. Without upping the intensity, there’s only one thing he could increase – the duration.

Cardiovascular Crash Course

The human body can perform a virtually limitless amount of movements. They range from briefly intense displays of power (squatting 800 pounds or sprinting 100 meters) to incredibly long displays of endurance (running an ultramarathon, reading Oscar Arden’s column in Muscular Development, etc.).

To simplify things, we’ll say that the short, intense bursts of energy are fueled by the phosphagen energy system. That’s where we get our energy for heavy singles or breaking the line of scrimmage. The next pathway is the glycolytic pathway, and that’s where our fuel comes from in a wrestling match or mixed martial arts fight. And finally we have the oxidative pathway, where we get our energy for everything else, from a mile to a marathon.

As you tap your phosphagen energy, you’re working in the anaerobic zone, where the presence of oxygen isn’t necessary. Anecdotally, we find that working in that first pathway produces a hypertrophic (muscle building) response – i.e., we see everyone from powerlifters to sprinters to field athletes gaining muscle by training almost exclusively in that zone. As you enter the first phase of the glycolytic pathway, you’re still in the anaerobic zone, although halfway through, you pass into the aerobic zone, where oxygen becomes necessary. Training in the glycolytic pathway will also build muscle, and this is the energy pathway from which we see the greatest hypertrophic response; our traditional bodybuilding sets of 8-12 reps are performed in this pathway.

As you can see, as the duration of our work time increases, we shift from the phosphagen phase into the glycolytic, and finally into the oxidative. And, as you can guess, that’s also where the hypertrophic response becomes less and eventually reverses itself.

As a bodybuilder, wouldn’t you want to keep your cardio training in the same pathway as your weight training? I mean, if we’re serious about building muscle while losing fat, why would we take everything we know about hypertrophy and throw it out the window? Well, that’s exactly what we’re doing when we perform long bouts of traditional cardio, because after three minutes of steady training, we enter the oxidative pathway. But how do we burn fat without long bouts of oxidative work?

Playing the Numbers Game

High Intensity Interval Training (HIIT) is a protocol of brief, intense sprint work separated by rest periods. Tremblay et al. compared HIIT with endurance training (i.e., traditional cardio) and found that the HIIT trainees showed greater fat loss without burning more calories. In fact,

they lost 300 percent more fat, while every calorie burned translated to a ninefold loss of subcutaneous body fat, as compared to the traditional cardio group. Take that, lowintensity gurus!

In 1996, Tabata et al. showed that interval training consisting of 20 seconds of work separated by 10 seconds of rest improved aerobic capacity as well as traditional cardio, but also improved anaerobic function as well (which is exactly what we’re trying to achieve).

Kelleher et al. examined excess post-exercise oxygen consumption (EPOC), which indicates an elevated posttraining metabolism, and found that supersets created a greater rise in metabolism than traditional sets, while Bahr and Sejersted found that an exponential relationship between exercise intensity and the rise in EPOC. Thornton, in 2002, found that even if total work remained the same, the intensity of the exercise was proportionate to EPOC.

Put more simply, you’ll lose more fat faster and hold on to more muscle when your cardio starts looking more like your weight training – and you’ll even burn more calories when you’re not training.

Because I S.A.I.D. So

Who do you think looks closer to a bodybuilder: a sprinter or a marathoner? Both have extremely low bodyfat, but the sprinter displays a much higher level of muscularity. In fact, because the sprinter carries the same amount of bodyfat but with a (much) higher amount of muscle, he actually possesses a lower bodyfat percentage. We see this universally and with athletes of all denominations: top mixed martial artists display incredibly low bodyfat percentages, and they’re doing it with ultra-intense training, not hour-long walks.

This isn’t an isolated incident, but rather a spectrumwide phenomenon that repeats itself throughout the athletic world. This is because of a principle known as specific adaptation to imposed demands, or S.A.I.D. Put simply, your body adapts to the demands you place on it.

Bodybuilders, probably due to the poor advice of some very popular gurus, and some pharmaceutically skewed numbers, aren’t imposing the right demands on their bodies for optimal fat loss. They’re losing fat, but they’re doing it in the worst way possible!

That last point is important because I’m not arguing that low-intensity cardio won’t help you lose fat. There’s a successful pre-contest guru who advocates a ton of low-intensity cardio, combined with a ketogenic diet, and copious amounts of pharmaceutical assistance for his clients … and he’s successful. But in the end, success proves that his methods work, not that they are optimal. I’m not interested in what works; I’m interested in what
works best!

The scientific data, combined with the empirical data gathered by looking at various athletes, tells us that the optimal way to get lean is to ramp up the intensity of our cardio, not to extend the duration. What I’m suggesting is so different that I hesitate to even call it cardio at all, because it looks nothing like walking on a treadmill to nowhere or riding a bike that doesn’t move.

Your Fat-Burning Anti-Cardio Workout

Now we know what we need from fat-burning workouts: We need them to be intense. We need them to be brief. And we need them to stress our bodies to adapt. So what do we do? To help us out, I asked a bunch of top-notch coaches how they’d design a routine for losing maximum fat in minimum time. These workouts are designed to be done instead of whatever cardio routine you’ve been doing (or not doing), after a weight session or alone:

A Reminder

When these workouts get easier, you need to increase the weight or work faster so you finish more reps and rounds. In no case should you be spending more than 20 minutes on these circuits … we’re looking to up the intensity, not the duration. Remember, we want to commit four hours per week to getting ripped for four months, not the other way around.

All of these routines can be done without leaving your gym, and without a ton of equipment. They don’t require an insane amount of space, and you can do them virtually anywhere. All they require is that you’re willing to stop wasting your time and start upping your intensity.


Mike Mahler, author of The Aggressive Strength Solution and The Kettlebell Training Manual, suggests the following simple-but-effective workout:
Alternating-hand kettlebell swings × 3 minutes
Rest × 1 minute
Choose a kettlebell that allows you to perform three to four rounds and work up to five. When you can do five rounds, use a heavier ‘bell. You can also break this routine up into Tabata training (20 seconds of work, 10 of rest), and do 4-minute rounds with a minute of rest between each.


Crossfit is a workout system based on constantly varied, high-intensity functional movements. This following circuit of two exercises, designed by a certified Crossfit coach, is to be performed for ten reps on the first circuit, nine on the second, and so on, with 30 seconds of rest between each circuit:
1A. Deadlifts × 10, 9, 8, etc…
1B. Burpees × 10, 9, 8, etc…
Rest × 30 seconds


Coach Will Heffernan is the owner of the Informed Performance gym in Dublin, Ireland, where many of the country’s top athletes are trained. For the following circuit, complete as many rounds as possible in 20 minutes:
1A. Dumbbell (DB) squats × 10
1B. DB press × 5 per side
1C. DB rows × 5 per side
1D. Step-ups × 5 per side
1E. Pull-ups × 5
1F. Push-ups × 10


Jason Ferruggia is the owner of central Jersey’s most infamous training spot, Renegade Gym.
1A. Burpees: 30 seconds
1B. Jump-rope sprints: 30 seconds
1C. Bodyweight squats: 30 seconds
1D. Double-arm kettlebell swings: 30 seconds
1E. Jump-rope sprints: 30 seconds
1F. Mountain climbers: 30 seconds
That’s three minutes of work, and then you can rest 60–90 seconds between. Repeat 3–4 times. Constantly try to increase the number of reps you’re doing per round.

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