Could it be that too much cardio is bad for you? If you’re tired of all the stepping, climbing, walking, and running, you might think great news is coming. But truth be told, most of us are likely in no danger of overdoing it in the cardio department. However, if you dream of long runs or hours on the bike, you should know it is, in fact, possible to do too much!

What Are the Benefits of Cardiovascular Exercise?

Cardiovascular exercise, or “cardio” for short, is, without a doubt, a vital facet of any well-rounded workout program. Proper amounts of cardio can help relieve stress, boost your lung capacity, alleviate depression, reduce fatigue, ramp up your immune system, and strengthen your heart. It can also help you lower your blood pressure and lose weight. Unfortunately, some people just tend to take things too far, and that’s when too much cardio can become bad for you.

What Happens When You Do Too Much Cardio

You’ve undoubtedly heard myriad sayings regarding “when you have too much of a good thing…” and, unfortunately, the same can hold true when it comes to cardiovascular exercise.

How is this possible?

Cardio can turn counter-productive when you start experiencing negative side effects. Here are some of the telltale signs if you’re doing too much cardio:

1. You’re losing muscle—muscle is metabolically active tissue, meaning it requires calories (and burns them) to survive. So, logically, the more muscle you have (or build) on your body, the more calories you require, just to exist. Whereas body fat, on the other hand, requires nothing to survive. Additionally, if you’re continually overloading yourself with cardio and not properly refueling, you’re probably burning muscle for fuel, and that is never a good thing. As discussed, muscle is metabolically active and body fat is not, so if you’re burning muscle, you’re lowering your metabolism… and that means you’ll need to eat less or you’ll put on weight. Clearly, this is a huge downside.

2. Repetitive use injuries—cardio, by its very nature, involves a lot of repetitive motion, and these can turn into injuries if you’re doing too much cardio and not allowing yourself to recover. If you start experiencing nagging pains that just don’t seem to subside over time, it may be time to ease off on the cardio training a bit.

3. Achy Joints—if your joints are consistently sore and it never seems to let up, you might be doing too much cardio, or at the very least, too much high-impact cardio. Learn to listen to your body and pay attention to subtle signs of an oncoming injury that can occur over time. For example, you might notice some sensitivity in your ankle during your morning run. Normally, that could be something that quickly subsides once you stop the run. However, if you notice a pain that continues and even intensifies over time, you could be putting too much repetitive stress on your joints, and it’s time to take a step back before you have to deal with an injury.

4. You’re not losing body fat—in toxic amounts, stress is a huge negative that can really thwart your fat-loss progress. Constantly elevated levels of the stress hormone cortisol can keep your body from losing fat. Increased cortisol levels can cause you to want to eat more and eat more of the wrong things. In fact, consistently increased stress hormones in your body can have you storing extra body fat, especially in the stomach area.

5. You’re not sleeping like you should—too much cardio can also disrupt your sleep patterns, which can add to stress and retaining body fat. Exercise, in the right amounts, can ideally foster restful sleep, but when you do too much, things can rapidly go in the wrong direction. Too much stress from excessive cardio will rev up your system to the point where it just can’t settle down.

6. You lose your fire—when you suddenly notice that you no longer feel like working out and you’re just tired all the time, it might be time to take a step back. If your motivation is waning and you’re just dragging yourself around, you could be suffering from burnout. This can lead to a suppressed immune system and even sickness if you keep pushing your limits. Instead, try taking a step back and relaxing a bit to truly make forward strides with your progress in the future.

What is the Right Amount of Cardio?

According to the Department of Health and Human Services, in terms of aerobic activity, “Get at least 150 minutes of moderate aerobic activity or 75 minutes of vigorous aerobic activity a week, or a combination of moderate and vigorous activity.” They go on to recommend that you break this amount of exercise up over the course of the week.

Now, keep in mind, if you have particular fitness goals in mind, or you’re on a deadline or participating in a sport that requires it, you may need to increase the amount of cardio you do for short periods of time. For example, if you are in a 12-week fitness challenge, it’s perfectly acceptable to ramp up your cardiovascular exercise to as much as an hour or more a day, divided into smaller sessions. Again, this is not the type of pace you would want to maintain year-round, but for a few weeks or months, it is acceptable.

Think of cardio as medicine… use it sparingly and in the right amounts for the goal at hand. Ramp up the amount slowly since your body gets used to anything you do. That means, if you consistently do an hour of cardio a day in a fruitless effort to lose that tummy roll, you’ll soon discover that your body has adapted to that daily amount of cardio. Now, to lose body fat, you’ll have to do even more cardio, just to “break-even,” metabolically speaking. That said, doing 20 – 30 minutes of cardio 5 times a week is a good recipe to follow for general fitness.

What’s the bottom line? More is not always necessarily better when it comes to cardio (or anything else). Keep the muscle, burn off the body fat, and stay uninjured… that is the perfect amount of cardio.