5 Cardio Mistakes That Are Killing Your Fitness Gains

image of female running on treadmill. Are you making these cardio mistakes?

Cardiovascular exercise is an important part of any training program. After all, your heart is the most important muscle you have! When it stops, so do you – permanently. Cardio not only helps your heart stay healthy, but it’s also a calorie burner and a mood enhancer. Who doesn’t enjoy the feeling of endorphins flowing through their veins after a cardio session! However, certain habits can reduce the benefits you get from aerobic exercise. How many of these cardio mistakes do you make?

Cardio Mistakes #1: Distracted Cardio

Have you ever seen someone at a gym reading a book as they pedal on a reclining bike or a chatty individual talking on their phone as they walk on a treadmill? Some gyms have screens on the walls so gym-goers can watch television while they exercise. But, is this really a good idea? Studies show that multitasking doesn’t make us healthier or more productive and it causes excess stress. When you’re doing cardio, focus on your movements, especially your breathing as well as how hard you’re working so you can adjust your efforts accordingly.

Cardio should be a mindful pursuit. The extent of your distractions should be upbeat, music playing in the background for motivation. Some studies show that music makes cardio feel easier – but avoid other forms of distraction. Also, be aware that the risk of injury goes up when you’re doing cardio while distracted. Use exercise as a break from technology!

Cardio Mistakes#2: Overdoing the Cardio

The reasoning goes like this: Cardio burns calories. Therefore, I must do more cardio to lose weight and I must do it every day. Perish the thought! The reality is we often overestimate the calories we burn when we do moderate-intensity cardio. Plus, studies show that people overcompensate for the calories burned through exercise by eating more. That’s why cardio alone isn’t particularly effective for weight loss and doing more of it won’t necessarily benefit you. It’ll just make you tired.

Overdoing the cardio has other drawbacks as well. If you do cardio for an hour a day, how much energy and focus will you have when you have to devote to weight training? Some studies show that doing cardio before strength training the lower body interferes with lower body strength gains. When you do 40 minutes of running or cycling before a strength training session, your legs will already be in a fatigued state and you likely won’t maximize your performance.

In fact, studies show that the benefits of cardio follow a bell-shaped curve. More is better only up to a point. At some frequency, the benefits start dropping off as fatigue sets in. In extreme cases, too much cardio can lead to overtraining and elevation of cortisol with a variety of negative repercussions, including suppression of the immune system and muscle breakdown. Two to three cardio sessions weekly are enough to get the benefits without exhausting your body.

Cardio Mistakes #3: Not Varying Your Cardio

You might have your favorite form of cardio but that doesn’t mean you shouldn’t vary your cardio routine. Let’s say your favorite cardio workout is running. No doubt, running can improve your cardiovascular health, but you also have to consider the constant pounding on your joints and the fact that you’re doing the same repetitive movements over and over again. This increases the risk of overuse injuries. Varying the type of cardio you do as well as cross-training helps reduce the constant impact on your joints, especially if you choose some low-impact cardio options such as spinning or stepping. Diversifying cardio training also helps reduce boredom and prevent plateaus where fat loss slows because your body has adapted metabolically to the exercise you’re doing. Enjoy your favorite form of cardio but add some variety too.

Cardio Mistakes #4: Doing Only Moderate-Intensity Cardio

Moderate-intensity cardio can improve your aerobic capacity and endurance, but high-intensity interval training can enhance both your aerobic and anaerobic energy systems. Each system is important for optimal fitness. As aerobic capacity improves, your ability to sustain moderate-intensity exercise goes up and you have more stamina and endurance. But, in response to high-intensity interval training, you develop anaerobic fitness and the ability to tolerate and clear the lactic acid that builds up during high-intensity activities, like sprinting. High-intensity training gives you both benefits in a single workout. That doesn’t mean you should do HIIT training every time you do cardio. It’s easy to overdo it if you train at a high intensity too often. Aim for no more than two or three high-intensity sessions per week. You could add a third weekly session of moderate or even low-intensity cardio if your focus is building endurance.

Cardio Mistakes #5: Not Adjusting Your Calorie Intake Accordingly

As mentioned, cardio doesn’t give you license to eat whatever you like. Sure, you worked hard, but thirty minutes of moderate-intensity cardio typically only burns 200 to 300 calories. Many post-workout snacks more than exceed this. Cardio seems to transiently suppress appetite but it doesn’t seem to curb appetite longer term. So, it’s still important to watch what you eat if you’re trying to control your weight.

At the other extreme, some people, in a zealous attempt to lose weight quickly, do hours of cardio each week and drastically cut back on calories. This, too, is self-defeating. You may lose weight transiently using this approach, but your body will quickly adapt and become metabolically more efficient. This approach can also boost the stress hormone cortisol and lead to muscle loss. If it’s sustained, you can suffer more serious repercussions, including bone loss, infertility, hormone imbalances, and suppression of the immune system. It’s better to switch some of your focus towards strength training and work on improving the quality of your diet rather than drastically cutting calories.

The Bottom Line

Cardio is important for improving endurance and stamina and because it improves heart health and lowers the risk of some chronic diseases. But, watch out for these common cardio mistakes and do your best not to make them!



Psychol Sci. 2013 Jun;24(6):869-79. doi: 10.1177/0956797612463581. Epub 2013 Apr 10.
J Strength Cond Res. 2011 Apr;25(4):1104-12. doi: 10.1519/JSC.0b013e3181d09ec9.


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