If you’re like most people, you joined the gym to lose a few pounds of fat, build some muscle, and improve your overall body composition. Likely included in your weight loss plan was a “healthy” dose of steady-state cardio where you spend upwards of 60 minutes slogging it out on a treadmill, bike, or elliptical machine staring at the clock hoping and praying that somehow time moves faster. If this sounds like you, trust us, you’re not alone. Millions and millions of gym rats every day spin their wheels (literally) on cardio machines hoping that it will provide the results they seek.
Unfortunately, cardio is not the answer to your weight loss woes, but beyond that, cardio isn’t even a requirement for fat loss! Yes, you read that right. You can lose fat without ever having to take one step on a treadmill or one pedal on a bike. Surely, you think we've gone mad, or had a few too many scoops of pre-workout, but hear us out about the many reasons why cardio is not the long-term solution to weight loss.
6 Reasons Why Cardio Isn’t the Answer for Weight Loss
It Doesn’t Burn That Many CaloriesWe won't deny that cardio does burn calories, but in the grand scheme of everything, it doesn't burn all that much. For example, a 220-pound man only burns about 150 calories during an hour of leisurely walking and roughly 325 calories during an hour of hiking or swimming. That’s a paltry amount of calories, and could easily be wiped out by two scoops of protein powder consumed post workout (the average scoop of whey protein contains 120-160 calories on average). You see, first and foremost, fat loss is about creating an energy deficit. The most time-efficient way to accomplish this isn’t by spending hours and hours each week, grinding it out on the treadmill. It’s by reducing your calorie intake and creating a calorie deficit. When you consume fewer calories than your body needs consistently, it has no choice but to turn to body fat stores to get the energy it needs. Yes, steady-state cardio is excellent for improving your overall cardiovascular health, and the stronger your cardiovascular system is, the quicker your intra-set recovery will be during training (which allows you to accomplish more work in a shorter amount of time, thereby burning more calories per unit of time in a workout). But using it as the primary driver for weight loss is a massive drain on your most valuable resource -- time. Finally, over time, your body becomes increasingly more efficient at performing whatever type of cardio you're doing. As it becomes more efficient, it burns fewer calories performing the same amount of work. What this means is that while the “calories burned” readout on the cardio machine might say one thing, the actual amount you’re burning could be quite different.
Excessive Cardio Raises CortisolProlonged endurance exercise (i.e., chronic cardio) is a stressor to the body, much like any other form of exercise. When we're stressed, cortisol levels rise. <1> Why is this bad? Well, cortisol, in and of itself, isn't bad. It's necessary at times (such as when we're being chased). However, when cortisol levels are chronically elevated like they can be when we're exercising too much, it starts to do some slightly funky things to our bodies. Not the least of which is muscle breakdown. You see, cortisol is a catabolic hormone, and when we’re stressed all time cortisol levels stay high, never having a chance to return to normal, which puts us in a very unfavorable position for building and retaining muscle. Furthermore, chronically elevated cortisol levels can also disrupt our natural hormone balance between estrogen and testosterone, not only making it more challenging to lose fat, but it may cause us to store more fat, especially in the abdominal region.
Chronic Cardio Can Increase HungerAs we just mentioned, exercise increases stress levels, and studies have found that when we’re stressed, we tend to have more intense and frequent hunger pangs and cravings <2>. Combine this with a calorie deficit and you’re asking for trouble during your fat loss phase. On top of that, other research notes that low-intensity (steady-state) cardio stimulates appetite <5>, again not something you want to have to deal with when you’re already reducing your daily calorie intake.
Cardio Doesn't Build muscleAnother big downside to using cardio as the primary method for chasing weight loss is that performing too much of it can actually hinder muscle growth and at worse eat away at your muscle tissue. <4> The reason this is so alarming is that when you lose muscle, your resting metabolic rate (RMR) decreases. <3> When you lose muscle, your body burns fewer calories, which means you'll either have to diet on fewer calories or increase your level of exercise even more to create the energy deficit needed to burn fat and lose weight. This is why resistance training is one of the best things you can do to get lean. Resistance training helps improve body composition because it builds muscle. It also helps retain muscle when your dieting, which is the time your body is at the highest risk of losing muscle. And remember, when you increase the amount of muscle you're carrying, you increase your resting energy expenditure (the number of calories the body burns when it's sitting still). The reason for this is that muscle tissue is more metabolically active than fat tissue and requires more calories to function, even during periods of low physical activity than fatty tissue. Furthermore, if you’re not resistance training and purely using cardio as your form of exercise to lose weight, you’ll likely end up with the dreaded “skinny fat” look where you might be thin, but your body also looks soft and squishy, not the lean, ripped, and toned look you were hoping for.
Too Much Can Impede RecoveryPerforming too much exercise (of any kind) can impede the body's ability to recover sufficiently from one training bout to the other. You see, we each have a limited ability to recover, and when we exceed that, performance goes down, we're at risk for muscle loss and a higher chance for injury. When you're dieting, recovery capacity is already limited due to the decreased amount of calories you're eating each day. As such, recovery comes at a premium, and since the focus of your training, while dieting should be on resistance training (to build and retain muscle), that doesn't leave lots of room for cardio. Sure, the occasional bout of HIIT or leisurely walk is ok when dieting for fat loss, but you don’t want to be spending hours and hours on the elliptical during the week. That time would be better spent recovering from your weight lifting sessions and planning your meals.
It’s UnsustainableLet's conduct a thought experiment for a moment and say that you're maintenance calories are 2400. However, you regularly consume ~3000 calories per day, which means you need to burn off an additional 600 calories each day through cardio to maintain your weight. Now, if you want to lose weight, that means you’d need to burn off another 500 calories or so every day to lose just one pound per week. Is this sustainable? Can you go and perform a few hours of cardio every day to out-exercise your overeating? For a week or so, maybe, but long-term, not a chance.
TakeawayCardio is excellent for improving cardiovascular health, but when it comes to fat loss, it's not the best option and for more reasons than one. That’s why when it comes to losing fat, we recommend focusing on your diet first and creating a calorie deficit. At the same time, it’s also important to perform resistance training workouts 3-4 times per week, as this provides the stimulus your body needs to help retain and build new muscle tissue while dieting. After those two things are in place, then you can look to supplementing your cardio with thermogenic fat burners such as Steel Core®, Steel Sweat®, or Shredded Steel®. We're fans of high-intensity interval training as it's time-efficient and doesn't put your muscles at risk for a breakdown like chronic steady-state cardio does. You can still perform a few minutes of cardio before and after your workouts as a warm-up and cool down, but using it as the primary mechanism for fat loss is a losing proposition. Be sure to checkout our 30 Day Booty Transformation eBook for exercises to use as a cardio replacement.
- K. Kuoppasalmi, H. Näveri, M. Härkönen & H. Adlercreutz (1980) Plasma cortisol, androstenedione, testosterone and luteinizing hormone in running exercise of different intensities, Scandinavian Journal of Clinical and Laboratory Investigation, 40:5, 403-409, DOI: 10.3109/00365518009101862
- Gluck, M. E., Geliebter, A., & Lorence, M. (2004). Cortisol stress response is positively correlated with central obesity in obese women with binge eating disorder (BED) before and after cognitive-behavioral treatment. Annals of the New York Academy of Sciences, 1032, 202–207. https://doi.org/10.1196/annals.1314.021
- Speakman, J. R., & Selman, C. (2003). Physical activity and resting metabolic rate. The Proceedings of the Nutrition Society, 62(3), 621–634. https://doi.org/10.1079/PNS2003282
- Brillon, D. J., Zheng, B., Campbell, R. G., & Matthews, D. E. (1995). Effect of cortisol on energy expenditure and amino acid metabolism in humans. The American Journal of Physiology, 268(3 Pt 1), E501-13. https://doi.org/10.1152/ajpendo.1995.268.3.E501
- Erdmann, J., Tahbaz, R., Lippl, F., Wagenpfeil, S., & Schusdziarra, V. (2007). Plasma ghrelin levels during exercise - effects of intensity and duration. Regulatory Peptides, 143(1–3), 127–135. https://doi.org/10.1016/j.regpep.2007.05.002