Does Cardio’s “interference Effect” Really Reduce Your Performance?
Both cardio and strength training are important to your fitness – a fact that I have always known, but currently cannot shut up. I mainly do strength training (more precisely, a weightlifter ), and for a long time believed that I would work quite hard. But when I added more cardio to my routine, I saw that my exercise improved. Cardio is useful, who knew.
But there is a popular misconception about combining the two. The “interference effect” of cardio, your educated gym brother might tell you, is scientific evidence that cardio is killing your performance. Therefore, the less cardio you do, the more muscle you gain.
This is not true, although there are a few grains of truth that led to this belief. Let’s go over them and see where they really apply.
Time management is important
Every time you do cardio, you don’t squat. In this sense, the more cardio you do, the less time you have to exercise.
Runners have a similar reason to avoid strength training: they’d rather spend an hour on the road than an hour in a stuffy gym. That doesn’t change the fact that runners really need strength training , and lifters need to give their heart and lungs room to work.
How to solve this problem: Plan better. If you go to the gym on Monday, Wednesday, and Friday, you probably have a little time on Tuesday and Thursday that you can use to get on a stationary bike, watch a video of cardio dancing, or go hiking. (If walking is tiring enough, that matters .)
Even if you don’t have time for a full cardio workout, you can probably find a few minutes each day for a mini workout or a quick HIIT session (ideally real HIITs, not fake stuff , but better than nothing).
You must eat enough for both
If you are gaining muscle mass, you may be trying to help the process by eating enough food to gain weight. Some athletes may fear cardio because it burns calories, making it difficult to gain weight.
The solution is simple: just eat enough. The total amount of calories you consume should be balanced appropriately with the total amount you burn between daily movement and targeted exercise. If your weight is going in the wrong direction, adjust your diet or exercise to get back to normal.
Cardio can interfere with growth, but only in extreme cases.
The grain of truth in this myth is that there have been studies in which people who exercise for both strength and cardio have less strength gains than people who only train for strength. You can find a summary of some of them here .
But the case is not closed on this. There are also studies that show that untrained people improve their strength despite cardio , and show that cycling may not be as disturbing as running, if at all . And if you are not particularly specialized in your sport, the interference effect may not matter at all.
The effect is also quite small, even where it does exist: cardio does not prevent anyone from gaining muscle mass, but simply represents a possible compromise. So even if the interference effect is true and even if it applies to you personally, it still doesn’t kill your accomplishments – it just hurts them a little at worst.
Here we can also use common sense. On the one hand, no one was an elite marathon runner and an elite powerlifter at the same time. In any case, you need completely different body types and training schedules for these purposes.
On the other hand, there are many athletes who combine impressive strength with incredible endurance. If you don’t believe me, check out the CrossFit Games. It’s possible that the world’s best crossfitters might be a little stronger if they didn’t have to do bike sprints as well, or that they could run faster if they didn’t have to lift weights as well. But their training clearly allowed them to become good both ways.
Cardio’s are really good for lifting
So maybe there is a little interference effect, maybe not. You may be tempted to err on the side of caution and just not do cardio and focus solely on strength training, but this is not a risk-free solution. Let’s talk about what you leave on the table if you completely neglect cardio: Performance.
Cardio training (or “conditioning” if you want a clearer word) will make your heart bigger and stronger, and increase the size and number of your blood vessels. This helps your body get better oxygen and nutrients to the muscles and remove waste products from the muscles. All this helps to recover faster between sets of exercises.
Since I, personally, have added more cardio to my life, I’ve noticed that I can do a ton more work out in the gym. I used to have to sit for five minutes between sets of heavy squats; if I was working on the big deadlift, I could wait even longer. If my program required a triple clean and jerk, my lungs would be burning as much as my muscles by the time I finished. This all makes sense, since hard exercise puts stress on your entire body.
But now I run a few times a week and try to do extra workouts (light lifts, like curls) with as little rest time as possible. I also include some conditioning exercises in my routine, such as carrying sandbags and swinging kettlebells. These movements give my heart and lungs a workout similar to what they would get from an interval cardio session.
And now I can do my workouts with ease. Between sets of squats, three minutes are enough. I can create a pattern of presses, curls, and deadlifts and do it with little or no rest. As a result, my workouts are shorter than before. Sets of 20 reps are more difficult than impossible. If I have to do two lifts right after each other in a competition, I don’t have to worry about being unprepared for the second. And, importantly, as my workouts have become easier, I can use the same amount of time to do more work. I am confident that I am now gaining strength and muscle more efficiently than when I had to take these long breaks. So try some cardio – it might help you too.