Do You Need Cardio To Build Muscle?

If you were to ask me this question back when I was 18 years old, I would have said no. Absolutely not – You don’t need any type of cardiovascular exercise when trying to build muscle mass.

Back than, I used to be of the mind that in order to build muscle mass, you absolutely and whole heartedly must concentrate on hitting the iron hard and heavy – Without any muscle sacrifice from exercises that takes away from building muscle (Or so I thought).

Back than, cardiovascular exercise was nothing more than an afterthought. I wouldn’t even dream of hopping on the treadmill or exercise bike because I really thought they would make me shrink.

But, you want to know something? I used to walk back and forth to the gym everyday. The gym was a 20 minute walk from my parents house, so that meant I was doing 40 minutes of cardio exercise each and every day.

However, as I’ve gotten older and more experienced in the iron game, I’ve come to the conclusion that cardiovascular exercise is much too important an exercise, especially when trying to build muscle mass, to be completely taken out of a muscle building routine. After 20 some odd years pumping iron, I’ve had the opportunity to try many, many routines with and without some type of cardiovascular exercise included.

I’ll be completely honest with you. My workouts are always better when I’m up to snuff in the cardio department. I can do more reps, I can handle more weight, my energy levels are higher, and I feel a whole lot better knowing I’m in shape.

There are many benefits to improving your cardiovascular fitness, such as:

  • Improved heart and lung capacity;
  • Improved fat burning capacity;
  • Improved bone density;
  • Improved energy levels

However, for me, it has always been about how it will affect my muscle building routine. Will add or take away from my muscle building efforts?

Personally, the most important aspect of an improved cardiovascular system, for muscle building is the fact that there is more oxygen flowing to and from your muscles. It only makes sense when you think about it. The body tires when it doesn’t have the necessary oxygen to perform a certain task. When your body becomes exhausted from the lack of oxygen, you become weaker.

However, with an improved cardiovascular system, your body has the capacity to take in much more oxygen which means you can do;

  • More repetitions;
  • More sets;

Let’s use the squat as an example. I’ve been doing this exercise for years and I have a love/hate relationship with it. I know I have to do it, but I hate doing it. Now, I know that in order for me to build slabs of beef on the bottom half of my body, I need to be hitting the 8 to 12 repetition mark for squats.

That means using heavy weight with a high number of repetitions. Anyone who’s been doing squats to build leg mass, will testify that it takes a lot of effort, intensity, and will to get the most from this exercise. It also takes a lot of wind.

When you’re nearing the 12 rep range with a heavy sitting on your back, you’re going to be breathing pretty hard. If there is limited oxygen capacity in your lungs, you will have a much harder time performing this exercise than if you had more oxygen available. I always have much, much better squat workouts when my cardiovascular fitness is improved.

Also, improving your cardiovascular system will allow you to eat more muscle building calories, while keeping your body lean and healthy. Cardiovascular exercise increases the amount of energy you expend, which means more calories are burned. This allows you to increase the amount of calories you ingest.

Now, the only time I don’t recommend cardiovascular exercise for muscle building is if you are already super ripped and underweight. I’m not saying stop all cardiovascular exercise, I’m saying you need to get to a level where your daily caloric intake exceeds that of your daily caloric expenditure. That is, you need to stock up on calories.

High cardiovascular exercises such as running and swimming takes up a lot of calories and if you’re burning more calories than you’re taking in, you’re never going to build a high level of muscle mass. In this case, you need to appropriate those calories to your muscle building efforts, instead of your cardiovascular efforts.

Think of it as a budget. You only have so much dollars to work with so you need to apply those dollars (calories) where you will get the biggest bang for your buck (building muscle). Which do you need more? Muscle mass of cardio?

What I’m saying here is that an improved cardiovascular system will always improve your muscle building efforts. The more oxygen you have to perform and exercise, the better it will be. What types of cardiovascular exercise should you do? This can be any type of aerobics exercise you enjoy. That can be walking, biking, or swimming. I strongly suggest you pick something of interest because, let’s face it, walking on a treadmill for 30 minutes in a dingy gym, is boring.

You can even do jumping jacks or running on the spot. The important thing is to start doing it. I’m sure after two weeks of constant and improved cardiovascular activity, your muscle building routine will also improve.

However, remember this very important point. If building muscle is your main focus, never fall into the calorie deficit area. Always keep your caloric intake higher than the amount of energy you are expending. This way, your body has the necessary calories to keep building muscle instead of having to break down protein (As in a calorie deficit) to maintain current muscle mass. For building muscle, you never, ever want your own body having to break down it’s own protein for energy – This is bad. Keep calorie levels high enough to give your body the necessary building materials to keep adding muscle mass.

Good luck!


Blake Bissaillion

Blake has been weight lifting for about 28 years now. He's 45 years of age and started seriously training when he was 18 years old.

Blake is the founder of, a successful fitness website that has been around for more than 15 years.