Most bodybuilders are probably familiar with the idea that “cardio kills gains.” While there is definitely some truth to the idea that some of the benefits of strength training and cardio can be canceled out by including both in the same workout, research suggests that it isn’t actually that simple.

It turns out, if you do it right, adding running to your training routine can give you some of the health and fitness benefits of cardio while maintaining or even improving your strength. 

How cardio affects strength training

Early research on the effects of cardio on resistance training showed that it did, in fact, inhibit muscle growth. However, their original studies included 5 or 6 days of 30 to 40 minute sessions of cardio. More recent studies show that a more moderate amount of cardio (2 or 3 days a week) can provide benefits, like increased blood flow, that actually contribute to muscle growth when coupled with resistance training. Below are 3 key things to keep in mind if you want to add running to your routine and keep making gains.

How to incorporate running into your strength training routine

1. Get the order and timing right

If your workout routine includes both running and strength training, the order in which you do them is crucial. If your goal is to increase strength and muscle mass, you definitely don’t want to waste the energy you’ll need for lifting by running beforehand. Hit the weights first and use your remaining energy for cardio.

It’s also important to keep in mind the amount of time that your body needs to recover from different types of exercise. Even if you break up your strength training and running into different training sessions, you may be losing gains if they are too close together. High-intensity cardio will impair your strength for up to 6 hours. You should aim to give your muscles enough time to recover between workouts but not so long that muscle soreness sets it. 

2. Choose the right running style

Not all styles of running will have the same effect on your muscles. A long, steady run of 20-60 minutes can compete with your strength training while sprinting may actually help you to increase strength in your hamstrings, quads, glutes, and calves. High intensity interval training (HIIT), or intervals of sprinting alternated with rest, can give you the cardiovascular benefits of running while preserving or even increasing muscle mass. 


3. Diet right

Running, especially steady state running, burns a lot of calories. That makes it a great exercise if you’re trying to lose weight, but it can be a problem if your goal is to build muscle mass. If you add running to your program, you’ll want to increase your calorie intake so that you’re eating about the same amount that you’re burning. Increasing carbs and fat in your diet and eating about 2 grams of protein per kilogram of body weight daily will keep you energized and able to keep building strength.  

A lot of bodybuilders and weightlifters worry about how running or other types of cardiovascular exercise might negatively impact their strength. But it might be more useful to consider the possible benefits. Improved cardiovascular health means quicker recovery time, better stamina for longer training sessions, and lower body fat. Ultimately, whether running has a positive or negative impact on your strength training comes down to how you do it. If you do it right, with these 3 things in mind, it might just give you the performance edge you’ve been looking for.