Does Cardio Kill Gains For Bodybuilders Seeking Growth?

We’ve all heard that cardio kills your gains, but how true is this?

It’s a common thing to hear. Cardio kills your gains. Cardio burns muscle that you’re trying to grow. Does cardio actually help me in my bodybuilding quest? We all hear these a lot. And for those of us looking to bulk up in mass and size, hearing this can deter us from doing cardio that we may actually need to benefit us. While our appearance is everything, knowing just what to do to get to that physique or maintain it can be challenging. With conflicting views like this flooding our heads, the choice to do cardio may actually be harder than we thought.

Cardio workouts are some of the most beneficial things we can do for our bodies. With many positive benefits surrounding cardio work, it would be negligent to skip out on a good cardio day. But again, what about my gains? Many have explored what happens when you mix cardio into your training routine and despite the legend of losing muscle and gains, the opposite might actually be true.

Let’s take a look at cardio and how you can strategically place into your routine to continue seeing gains while reaping the benefits of a good cardio workout. While you may still be skeptical, the benefits of giving this a try may just change your mind surrounding the myth of cardio and your bodybuilding gains.

Benefits Of Cardio For Your Health

While we all know many of these great benefits cardio can provide to our overall health and wellness, let’s first look at what cardio can do in general for us. From advancing our workouts to enhancing the quality of everyday life, cardio is something that is proven to be beneficial and effective.

  • Build endurance: Help enhance aerobic and anaerobic capacity for better breathing and stamina.
  • Strengthen your heart: Keep your heart pumping to encourage better flow and a healthier organ.
  • Aid in weight loss: Burn calories and control your appetite so unwanted fat starts to go away.
  • Increase mood: Release positive hormones to increase mood and help keep anxiety and depression at bay (1).
  • Prevent disease and long-term ailments: Work to manage high blood pressure and cholesterol while helping to prevent things like heart disease.

high-intensity interval training

Where HIIT Come Into Play

While longer forms of cardio are great for enhancing the above benefits, there is another form of cardio training that has taken athletes by storm. High intensity interval training (HIIT) is a fast-paced style of training where you perform intervals, alternating between high intensity and recovery-style.

This will allow to work at maximum capacity without struggling to complete an hour long cardio workout after a lift. When on, working at around 90% of your maximum effort will surely get your heart rate high and once you hit the recovery portion, you will be somewhere around 55-60% of your max effort to give your body time to come down before hitting it again (2).


HIIT is great for a number of benefits including promoting fat loss and changing your body composition. By keeping your heart rate high, you burn more calories, while also increasing your metabolism to burn more fat for fuel. With shorter, more intense workouts, you don’t lose muscle tissue and enter a catabolic state, but still get an increase in your endurance capacity and oxygen consumption. This short and convenient yet highly beneficial form of training is something to heavily consider, especially as a bodybuilder.

strong man

Benefits Of Cardio On Your Bodybuilding Goals

Now that we know what cardio does in general, and that HIIT is a great option for those who want a shorter workout, the fateful question comes back around: Does cardio kill those bodybuilding gains?

When it comes down to it, cardio is very beneficial for a bodybuilder. Not only does this have the ability to increase your endurance capacity to keep you training longer in the gym, but it will keep you healthier overall to promote that longevity. In a sport where your body is put through grueling workouts, strict dietary restrictions, and a good supplementation routine, you’ll need this extra help to keep you training and competing for much longer.

Working to schedule certain cardio days with your weightlifting days is important for a number of reasons. You want your body to fully recover and unwanted muscle soreness is going to happen. The extent is dependent on how much you let your body recover in between sessions. You also don’t want too much cardio on certain days which can start to degrade those hard earned muscles, so knowing just how much to put in on a given day will preserve that muscle mass and also give you everything a cardio workout can offer.


On days where you do lift, lower to moderate levels of cardio will not add too much stress and can keep you fired up and ready to go. On your off days of lifting, or at least lifting big, throw in some more higher intensity work. For those who enjoy running, while too much can be detrimental for you, a good run or two a week will get you outside and taking that fresh air. Or consider HIIT on this day to feel like you got a great burn while enhancing all areas of your training and performance (3).

What’s important to remember here is that cardio can hurt your gains if you do too much, but on the whole, it has the ability to seriously enhance all of your gains. Knowing when to do it and where to place it in your workout routine is what matters.

Wrap Up

We all know we need cardio. But we just don’t know how much. A common myth is that bodybuilders will lose out on muscle mass if they do cardio. But the truth is, cardio has the benefit of really enhancing our daily lives and giving us a great boost both inside and out of the gym. Look into strategically placing cardio into your routine and really see what can happen when properly used to your advantage.

Let us know what you think in the comments below. Also, be sure to follow Generation Iron on Facebook, Twitter, and Instagram. 

*Images courtesy of Envato


  1. University of Copenhagen (2018). “Cardio exercise and strength training affect hormones differently”. (source)
  2. Laursen, Paul B.; Jenkins, David G. (2002). “The scientific basis for high-intensity interval training: optimising training programmes and maximising performance in highly trained endurance athletes”. (source)
  3. Helms, Eric R.; Aragon, Alan A.; Fitschen, Peter J. (2014). “Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation”. (source)
Austin Letorney is a writer, actor, and fitness enthusiast. As a former rower, he has shifted his focus to sharing his knowledge of the fitness world and strength sports with others.