Priming The Cardio System!

One area that often lags is the cardiovascular system. It is not only healthy to get your heart and lungs in shape, it may also help you do better in key exercises like squats, deadlifts or leg presses. Learn why and how!
As a bodybuilder, you know a thing or two about triggering muscle growth. There are a lot of factors at play, and smart bodybuilders have learned to employ a broad selection of tricks to eke out the extra mile from every workout. But one area that often lags is the cardiovascular system.

It is not only healthy to get your heart and lungs in shape, it may also help you do better in key exercises like squats, deadlifts or leg presses.

Cardio Vs. Cardio

Before we start, let's make sure we compare apples to apples. I know you probably spend some time on the treadmill or stationary bike every week, likely staying in the usual zone around 65% of max heart rate. That's all fine and dandy for fat burn, but unfortunately it doesn't do that much for enhancing endurance, strengthening the heart and optimizing oxygen utilization.

A guy who pumps iron and spends 20 mins on the treadmill three times a week can have a surprisingly weak cardiovascular system since he never pushes himself outside the fatburn-zone. Stick with only low-intensity cardio for years, and a guy with washboard abs and respectable guns can be gasping for breath after a quarter-mile sprint. What's wrong with this picture?

The heart is a muscle like any other. But it's a tough mother - it works 24/7 and need to be squarely in the anaerobic zone to grow and get stronger. That means going beyond the traditional, restrictive 65% of MHR, into a range closer to 90%-95%. At that intensity we're talking serious huffing and puffing, lactic acid and buckling knees on the way to the locker room.

Calculating Your Heart Rate

There are two different ways to calculate your maximum heart rate and your target heart rates. Here are the two different ways!

Simple Target Heart Rate Calculator
Using the 220 - Age formula.

Enter Your Age - Then press Calculate.
Heart Rate
Heart Rate per minute
(75% - 85% of Max)
Heart Rate
15 sec count

The Karvonnen formula is more advanced since it also takes into account your resting heart rate. This is your heart rate at complete rest. To determine this, take your pulse for 60 seconds just before you get out of bed... or take it for 30 seconds and multiply by 2.

Advanced Target Heart Rate Calculator
Using the Karvonen Formula.

  • For your age, use a whole year. (Between 0 and 100)
  • Put your Resting Heart Rate in the next box. (Between 30 and 100)
  • In the % box, use a number between 50 and 85. Do not include the %.
  • Click on the Calculate button, and it will calculate your target heart rate or that percentage.
Your Age in Years
Resting Heart Rate
% of Maximum Effort
Your Target Heart Rate

The Catch-22 Of cardio

As a rule, cardio is viewed as a necessary evil that should always be kept at the bare minimum so as not to interfere with the muscle building process. Sure enough, there are valid reasons for cardio's bad rap. Cardio can burn muscle tissue. Cardio in conjunction with weight training can be counterproductive (depleting glycogen if done beforehand, worsening the catabolism is done afterwards).

Cardio also happens to be more boring than C-SPAN, and if you get stuck on the machine behind Mr. Beans-for-lunch-but-no-shower-in-a-week even the will to live begin slipping away.

On the other hand, you sort of have a vested interest in maintaining your cardiovascular system - it keeps you alive.

Not only will it lower your blood pressure and make you live longer, it will also help you perform demanding, full-body exercises. Heavy squats, for example, take an enormous toll on the entire body.

Anaerobic as the exercise may be - if the lungs can not process oxygen fast enough, you lose steam towards the end of the set and may fall a few reps short of what you could have done with a tip-top cardiovascular system. As you know, those last few reps are crucial when it comes to muscle building.

But here's the catch-22: you need to keep your heart and lungs in shape to lift more and to stay healthy, but in order to do so you may have to sacrifice some growth. So, how to approach this problem?

Ditching Low-Intensity, Going Interval

The solution that made most sense to me is somewhat unorthodox and may not sit right with old-school gymrats. That's ok - I'm not making any grand claims about this being a one-size-fits-all solution, so go with what works for you. That said, here's my take on the matter:

No more "fatburn" cardio. None. Instead, let's dust off the old concept of interval training. To recap, classic interval training is when you alternate between light jogging (below the intensity of regular "fatburn" cardio) and full sprint (90%-95% of MHR) on a flat surface. These phases can be as short as a few minutes, so you switch pace often - completely different from the ho-hum plodding along of "fatburn" cardio in the 65% MHR range.

Let's look at what happens here: the sprint phase is clearly anaerobic and gives the heart a thorough kicker. Since it is a high-energy, anaerobic activity, you get lactic acid buildup and oxygen debt (out of breath). As a bonus, studies show this type of sprinting can produce a jolt of natural hormones, not unlike that of weight training. This makes sense when you compare the physique of a sprinter vs. a marathon runner.

The jogging phase is basically the downtime in which you catch your breath, repay the oxygen debt and calm down your racing pulse. The objective is not to burn fat - it's to get you ready for the next sprint. The length of the jogging phase depends on your condition - if you're ready for the sprint in 3 minutes, that's when you switch to sprinting, if it takes 15 minutes... You get the idea.

Calculating calories burned with this type of interval training is obviously hard without being hooked up to a machine with a calorie counter (and even then it's more of a rough guess). For the sake of simplicity, let's assume the total calorie burn was 20% more than you would have burned when doing traditional, low-intensity cardio. If you had done consistent, high-intensity running, you'd probably get considerably more than the extra 20%, but remember that we have to account for more than half the workout being low-intensity jogging.

Since a good part of the workout was spent doing anaerobic rather than aerobic work, it is reasonable to expect more carbs than fat was burned. Still, the total amount of fat - compared calorie to calorie - may very well be about the same, since more total calories were burned during the interval training. This would make the de facto fat burn effect equivalent between interval and traditional fatburn training - except you got the added benefit of giving your heart a kick in the butt.

Real-Life Application

Before we move on, let's start by acknowledging that interval training requires a certain minimum level of cardiovascular fitness. If you get out of breath by walking up two flights of stairs or have other reasons to believe you're not doing too well, start by taking gradually longer bouts of continuous jogging in the 80-85% MHR zone before moving on to interval training.

One way to check your shape is to take your resting pulse. The average is 72 beats per minute. Elite athletes get it down into the 30s. What's your resting pulse? You can use this as an extra carrot - continue to check your resting pulse rate and make it a goal to cut it by 10 bpm!

Testing your pulse is easy! Place the tips of your index and middle fingers (not the thumb, which has a pulse of its own) over the artery and lightly apply pressure.

Try it first thing in the morning; before you step out of bed, where you count beats for a full minute. An even better solution is to buy a good heart rate monitor - and it will help you get valuable feedback during your workouts.

Ok, time to hit the track. Or is it? If you're 200+ lbs or have knee problems, chances are you don't want to subject your joints to that kind of jarring exercise on a weekly basis. The good news is you can substitute the running for an elliptical trainer, stairmaster or versaclimber. Even some treadmills are pretty forgiving. Being 240 lbs with old knee injuries I found a few tolerable ones, so look around. The problem with machines is that it may get tempting to go easier on the sprint-phase - don't let yourself slack off!

As mentioned earlier, the timing of the phases depend on your physical condition. If you're ready to start pushing up daisies rather than dumbbells after 2 minutes, slow down and accept that it will take a while to get there. A fit person can go with a 5 min sprint/10 min jog rotation, but again, apply common sense and ramp up according to your abilities.


How often, then? That depends on your body type and goals. If you're in good shape and just want to keep you cardiovascular system primed, 1-2 interval workouts per week in addition to your regular weight lifting should be sufficient. If you're joining the Marines in two months or have some other reason to boost your endurance, 3-4 interval workouts per week is more appropriate.

Finally, a word of caution on max-intensity cardiovascular training: if you are one of the many who stockpiled fat burners in anticipation of the ban on ephedra, you may want to skip the pills for your most intense workouts. You'll probably be ok adding the extra kick, but why challenge fate? Especially if you're not in the best of cardiovascular shape, that is.

Be sure to also check out:
Beginner's Bodybuilding Program!

Good Luck,