Within the lifting community, the mantra of cardio killing your gains is pretty common.

However, it’s an over-simplified statement.

The human body is very specific in the way that it adapts. If you weight train, your body will adapt to get stronger and build more muscle in order to get better at lifting weights.

Similarly, if you train cardio, through running or any comparable work, your heart and lungs will adapt to endure longer and be more efficient.

When it comes to training both, there appears to be interference only when you reach a certain point.

Marathon runners don’t look like bodybuilders and vice versa because their bodies specialize in vastly different activities. When you specialize in a certain task, you can only do so much of something else before it interferes with your ability to train in your specialty.

This can relate to the total time spent training, as in you may only have so much time for multiple activities and just can’t train for both optimally. Or it can be that doing multiple activities makes it so that you’re unable to recover from the training, resulting in decreased results either way.

In other words, you become closer to a “jack of all trades” but a “master of none”.

However, when it comes to cross-training, a specific dose of cardio can have a positive effect on strength training. It was found that a moderate volume of cardiovascular training helped to optimize muscular hypertrophy and strength gains. This was the result of an increased aerobic capacity improving one’s ability to strength train, resulting in greater gains. So the best-case scenario when it comes to building muscle and strength is to supplement your resistance training with just enough cardio to act as an active recovery and build aerobic capacity that makes your resistance training even more effective. Doing absolutely no cardio for fear that it interferes with strength gains would interfere with your strength gains. But at the same time, doing too much cardio will cause your body to not adapt for strength and muscle gains as well as it could otherwise.

So it’s about finding the right dose that allows you to keep seeing improvements.

To your good health,
-Coach Stephen

P.S. If you're looking for a qualified coach to help you get started, click here (please add a link to our contact page) to book your own complimentary consult!

References for further reading on the topic: