To Cardio… Or Not To Cardio…

There is a lot of buzz in the “lifting community” about whether or not cardio is good or bad when it comes to helping – or hindering – your ability to gain muscle size. A lot of people believe unconditionally that cardio can “kill your gains”, which is a vast oversimplification, and frankly, a misunderstanding of cardio and how it should be used for a complete fitness program.

The science behind the belief is that performing cardio prior to a resistance training session can decrease your energy levels, and negatively impact your ability to force your muscles to perform under tension. Since time under tension is the primary driver that aids in tearing down the muscle so that it can then rebuild itself stronger, it’s easy to see why cardio performed prior to a workout could negatively impact your results.

Secondarily, steady state cardio – or cardio that requires a steady effort – like a spin class or a long run, can cause dips in your testosterone levels. Testosterone, if you’ve been following this blog for some time, or just happen to already know a little about it, is one of the primary hormones linked to muscle growth. So it’s understandable why someone whose goal is to build mass, or sculpt larger, more defined muscle might come to believe that cardio is not going to help them achieve this goal.

So Are They Right?

Both of these issues: the decrease in energy and decrease in testosterone can and should be addressed. The first issue – decreased energy, and thereby performance is pretty simple to fix. Perform your cardio after your resistance workouts instead of before. This way, your energy levels are at their peak during your resistance work, and you can push your body to perform with maximum effort. This still doesn’t address the larger problem though, the drop in testosterone levels.

To deal with the testosterone issue, you need to understand what causes this dip. When performing steady state cardio, your body is undergoing enough stress that it begins to release cortisol in response. This cortisol response tends to happen after around 30 minutes of steady state cardio training, and elevated cortisol levels, have been shown to block testosterone production and it’s effects. The key to all of this is the time performing cardio exercise, 30 minutes a day 5 days a week won’t trigger this cortisol response, but is enough to protect your heart health. In fact, according to a study on NCBI, these shorter bouts of Cardio – either 30 minutes or less, or shorter interval variety, such as a HIIT workout, may actually increase testosterone levels.

Now that we understand the science a little better, addressing the possible testosterone dip seems pretty simple. You can still gain the benefits of cardio – increased oxygenated blood flow and overall endurance without the negative side effects of steady state cardio. In fact, cardio will also increase your blood oxygen levels and circulation, which actually can aid in faster recovery and better muscle building.

I’m Not Sold Yet… Sell Me.

OK, so maybe you’ve been living in a cave, or that last bit went over your head for one reason or another. Why should you care about cardio? Well, hopefully, you’re not just vainly pursuing a better looking body, but you’re interested in your overall health. If that’s the case, then I’ll give you three more great reasons to add cardio of some fashion into your workout plan!

A Strong Ticker

Let’s start with the most obvious – heart health. While it’s true that longer bouts of steady state cardio – the kind that might kill your gains – are best for heart health, the shorter 30 minute variety still elicit a positive response. Why is cardio good for the heart? Well, the heart is a muscle, and cardio vascular training is like resistance training for the heart. Specifically, the left ventricle. When this part of the heart grows bigger, more blood can fill it, and then get pumped out into the body, this is known as improved stroke volume. Think of it like taking a bigger stroke in a canoe, there’s more bang for the buck, these longer strokes in a canoe, or more volumetric pumps of the heart equate to increased efficiency. In this case, that means the heart doesn’t have to work as hard to pump the same amount of blood through the body – that’s a serious advantage!

Additional Capillaries

A discussed in our first point, a strong heart equates to more blood flow. In order to accommodate this increased efficiency, your body responds by creating new capillaries. Think of capillaries as streets on a map. The more streets on your map, the more efficient you can deliver products – in this case, the products we’re delivering are blood, oxygen and nutrients to your muscles. This means that your muscles can perform at a higher level, but it also means that they can recover quicker because they use the same network of capillaries to clear themselves of metabolites like lactic acid and other waste products. Since there are more capillaries – thanks to your cardio conditioned body, they can clear themselves quicker than someone who doesn’t have this cardio benefit.

The Ability To Do More Work, Easier!

Remember when we said that more capillaries equates to the ability for your muscles to work at a higher level? What that means to you is you’ll experience an easier time during your resistance training than you might if you didn’t include cardio. This difference isn’t something like doubling the amount of repetitions you can perform during a set, but you might be able to squeeze out an extra repetition or two per set because you’re more efficiently delivering oxygen to your muscles who are screaming for it to break down glucose, and metabolize it into ATP, which is the fuel your muscles burn when asking them to perform. You might think “only one or two more reps?” but most lifters know that it’s that last two or three repetitions before failure where the real work happens that transforms your body. So an extra rep or two may make the biggest difference in your workouts!

So What Is Brain Body Food’s Stance On This?

no, that’s not me!

At the end of the day, it depends on your goals. If your goal is to build mass, I’d stick with HIIT training and maybe shorter, not to exceed 30 minutes, steady state cardio 2-3 times per week. If your goal is overall health, then by all means, incorporate steady state cardio into your fitness program as intensely as you’re comfortable with! Because I’m a fan of a complete workout, I wouldn’t perform it instead of resistance training, but going on a long bike ride, hike, walk or run on your “off” days can be a great way to stay on your workout schedule, but allow your body time to recover in between your more intense resistance training.

Overall, the benefits of cardio training are proven, and worth it! Hopefully this article helps you understand why a little bit more, and may help some of you who are on the fence, or maybe experiencing a plateau or slump in your results.

Know someone who might like this article? Please share it with them, or via your social media network, it helps the blog out, and you never know who you might be responsible for motivating to live a healthier lifestyle!


Does Cardio Kill Gains?
6 Mistakes that are killing your gains
3 reasons to include cardio in your lifting program
Testosterone Responses to Intensive Interval Versus Steady-State Endurance Exercise

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