Before I go on, let’s look at “cardio” in more detail…

Cardio is a short term for cardiovascular fitness.  Cardiovascular fitness is really the measure of how “fit” your heart is.  Your heart pumps blood throughout your entire body and your blood carries oxygen (and other vital nutrients) which is necessary for your muscles to keep functioning.  And the more your muscles work the more blood/oxygen is needed.

So when you’re exercising, your heart has to be able to keep up with the demands of your muscles.  Which is why doing “cardio” is commonly associated with improving your endurance.  And better endurance, means you can do “cardio” faster and longer which means you can burn more calories and hence burn more fat.

Makes sense…right?

Well it’s true…cardio does help increase your heart function…but it’s not the only way.  It’s a little know fact, but strength training effectively improves your cardiovascular fitness as well.

Now, you can’t just go out and lift some weights haphazardly and think you’re improving your cardiovascular fitness.  The KEY to improving your cardiovascular fitness through strength training is intensity.  Strength training with high intensity allows 3 important things to happen:

1. Releases adrenaline which dilates your arteries in your muscles so more blood can go there

2. Lowers peripheral vascular resistance which basically allows more blood to be pumped from your heart (increased cardiac output)

3. The intense muscle contraction increases venous blood flow back to the heart.  This in turn helps your heart work more efficiently

Now, I know that cardio is still considered “king” for improving cardiovascular fitness, but here are a few studies that indicate otherwise.

This study compared the cardiovascular effects of intense resistance training on 2 groups of people - stable patients and patients with congestive heart failure.

The result showed that intense resistance training had no negative effects on the group with congestive heart failure and in fact it effectively improved the cardiovascular function for both groups.

This study proves that intense resistance training produces significant improvements in cardiovascular fitness.

Here’s a very interesting observation from Dr. McGuff:

“I have some clients with known coronary artery narrowing. Their coronary artery disease causes them to have angina, which is heart pain due to poor coronary artery blood flow. Despite exercising these subjects at a relatively high intensity, we have never had any episodes of angina. These same clients will get angina when walking uphill or exercising on a treadmill or bike. My theory (and it is still only a theory) is that walking does not produce intense enough muscular contractions to stimulate increased venous return which would augment end diastolic blood flow and coronary artery bloodflow. I believe resistance training increases venous return and coronary blood flow so that these subjects can tolerate a much higher intensity of exercise without experiencing angina.”

Furthermore this study found that full body strength training performed by a group of people with hypertension helped bring their blood pressure back down to normal levels.

Perhaps cardio is not “king” after all…plus let’s not forget that intense strength training is much more effective at burning fat than doing just cardio alone.

So if I had to choose between doing intense strength training or cardio, well for me the choice is obvious.  I’ve always been about getting the most out of any exercise/workout and if intense strength training helps me improve my heart health while burning more fat…I’m all about it.

But don’t get me wrong, I’m by no means saying that cardio is ineffective.  Cardio IS effective at improving cardiovascular fitness, but it’s not the only way, it’s not black and white like many people think.  And this is why I advocate using a combination of high intensity strength training and cardio training so you can get the best possible health and fitness outcome.