A common question among fitness enthusiasts, "Does Cardio Kill My Gains?" and people usually fall into one of three categories:
I enjoy cardio and the results it brings
I enjoy cardio but feel it makes me weaker
I hate cardio and it kills my gains
My opinion – if you fall into category 2 or 3, your nutrition is most likely the culprit. Cardio is not to blame for losing strength. It is not fueling your body properly that is the culprit, and thus your body responds by robbing you of your hard-earned strength and muscle.
[Cardio here is being defined as a monostructural workout. That is, pure running, rowing, or assault biking. Usually lasting 30+ minutes or longer.]
Over the last month I have increased my cardio in preparation for a 50k trail race. And by increase in cardio, I mean I went from zero or one day a week to two days a week. Not a ton of running, but still, a significant increase in weekly mileage. Looking at my recent InBody scan, I put on muscle, and lost body fat this past month. I follow Renaissance Periodization (RP) and when I go for a run, I eat more carbs. Sometimes I follow their 2-a-day training template, or I simply just up the carbs right before and after my run. Protein and fat intake remain the same.
I am a huge proponent of CrossFit in its ability to deliver General Physical Preparedness (GPP). In this case, I am proof you can be strong and do cardio. Too often people put limitations on their abilities based on the social stigmas associated with such activities. “If I want to be strong, I should not do cardio.” Or “If I want to be a fast runner, I should not lift weights.” I argue that you can do both and be better off for it. You can be strong and have a solid aerobic base, and you can be a fast runner with some muscle that powers you up hills and helps prevent injuries.
Lastly, I promote cardio for one big reason – it’s all mental. When you go out for a run, ditch the headphones. Let it be you, your mind, and nature. Learn to control your thoughts at certain times and let your mind drift at other times. Find the ability to turn the switch on and off. Learn how much of an impact positive self-talk really has. Then just wait until you get your first runners high. If you’ve never experienced it, it is truly a euphoric state where you are just on autopilot crushing your run and you feel amazing. This all leads to an increase in your aerobic capacity, which will make your CrossFit workouts even better! It’s gains all around in fitness, in addition to the health gains of a lower resting heart rate, improved blood pressure, a stronger immune system and more. Enjoy, and remember; feed the machine! The base of the CrossFit pyramid is nutrition for a reason!