Why Should You Never Do Cardio?
Cardio is the worst ever. If you really want to lose weight, do this instead!
These are the headlines I’m greeted with constantly on my News app in this modern world where everybody with a license to use the internet is an expert. Articles like this one proclaim cardio, yoga, crossfit, and pilates to be 4 of the 5 “worst exercises for fat loss.” I will add a sixth to their article – exercise is the worst exercise for weight loss. What?! Why?! Because as you lose weight, it becomes harder to lose more weight! Skip down about half way in this article and read about metabolic adaptation. Please don’t let this stop you from exercising!
The problem I have with these articles is the headline and the meat of the article are usually quite different. Case in point: in the first article* I linked above, almost every item has a statement under it that refutes the absolute of the headline. For example, it explains Yoga is a “worst” because “if you aim to shed pounds, you want to work as much of your body as possible to lose weight and stimulate your metabolism.” However, you’d be forgiven if you were left scratching your head because earlier it labeled CrossFit a “worst” because “[i]t's too intense.” As an aside, here is an experiment for you to do. Tell Erin you want a power yoga session, and see if your whole body doesn’t get a crazy hard workout.
For the sake of brevity, I’m only going to tackle one of these “worst” exercises today: cardio. But really, for all the people who will only read this far, the key points I want you to take away are:
1) you should have a well-rounded workout regimen that includes things you enjoy (restorative yoga, slow jogging, etc.) and things that stress your body (power yoga, high intensity intervals, etc.)
2) don’t overwork yourself to injury because, if you are injured, you can’t exercise as effectively, and
3) maintain a healthy diet.
A quick note before continuing: I run so I use running analogies below, but you can apply these concepts to any regimen including yoga, weightlifting, cycling, or whatever your flavor may be.
In Defense of Cardio
First of all, your body isn’t a bunch of different energy systems. It is one energy system**, and it’s incredibly effective at turning food into work. As Erin explored in her last weight loss blog, when you work out, you consume oxygen, and that burns calories. When you burn calories, you lose weight. If we hold all other variables constant (e.g. your food intake), the more oxygen you consume, the more calories you burn, and the more weight you lose. It doesn’t matter at all what exercise you do to effect this.
Naturally, if you bound up the stairs at work, you are going to consume oxygen faster than if you walk up them slowly. However, it is also true that you will be able to walk up them slowly for a much longer period than you will be able to bound up them before resting. If you keep walking long enough, eventually you will burn the same amount of calories. If you’re indoctrinated in the HIIT culture, you may be rolling your eyes at this distinction, but ask the 100 mile ultra-runner if he thinks he burned more calories per hour than the 16x400m at 5k pace interval runner over the last 24 hour period. Sure, during the hour the "hard" interval guy worked he probably burned more calories, but, over the entire day, the "slow" 100 miler wins every time.
So what is the most efficient way to burn calories?
This is where the arguments and absolutes start. Google it and you’ll get articles that say short bursts of high intensity are all you need and are more efficient than cardio at burning calories and fat. If you keep reading you’ll find more complete articles like this one. While you may indeed burn calories faster doing high intensity intervals, you may be able to burn more in total if you slow down and go longer.
Cardio workouts provide a multitude of benefits by themselves. If you do something simple like jogging at an easy pace for 30-45 minutes per day, you will see marked differences. Your lung capacity will increase, your resting heart rate will decrease, and you will potentially see blood pressure and bad cholesterol drop while good cholesterol increases. Will you see the same benefits with non-cardio workouts? Probably, and that’s the point I am making about having one energy system, but here are the two key reasons you need a well-rounded workout regimen.
1) You can only do hard intervals so many times before your body is over-worked or needs a rest. Cardio workouts perfectly fill in the gaps because they don’t require the same amount of recovery. Having these days built in also avoids that inevitable mental burnout from being persistently fatigued and dreading the 10x60 second all out efforts.
2) You will be able to bound up those stairs at a faster pace and for a much longer duration if you regularly do correctly paced cardio workouts. This is why elite runners training to race the mile will run distances far exceeding a mile at paces far slower than their mile paces. This means that for every hour you put into cardio workouts, your short burst workouts will be stronger and more effective when you decide to do them***.
Do the type of exercise that you enjoy because consistency is much more important than efficiency. Have a well-rounded regimen that includes at least some focus on nutrition. Be skeptical of any headline you see with internet experts like me (or even bona fide scientists not familiar with the topic they are studying) claiming <insert item here> is the “worst” or “best” or “only” thing you could possibly do to effect the results you want.
If you are looking for a well-rounded regimen, email Erin, and she can work up a workout tailored to you. Tell her I said you can get a one-time discount on a private yoga session for reading this far.
*I’m not picking on the author of this article. They are in good company and just happened to be the first result on Google. I have seen dozens of similar articles, and I totally understand what this particular article is saying. In fact, buried in the middle, it says exactly what it means to say all along: “[y]ou're likely to lose more weight if you combine a healthy diet with a moderate exercise program that's … sustainable." I did a mental face palm when I saw their “best” workouts and how closely they resemble the “worst” workouts. Three examples: 1) Tabata is routinely used in CrossFit. 2) Boot camp is lauded by the article for “boost[ing] your [!?!] cardio [!?!] fitness.” 3) Strength training can be done with your bodyweight in Yoga and Aerial Yoga.
**You can quote tons of internet material to me about anaerobic, aerobic, glycolysis, ketosis, thresholds, etc. and call me wrong about this. It's difficult to find in the internet abyss, but I’m not the only person who believes and professes this point of view, and while it may be considered exercise blasphemy, the fact is your body runs on ATP and doesn’t really care how it gets it. The processes whereby you produce ATP have different outputs, but the non-ATP stuff is basically non-fuel waste products.
***This is partially because you will be more effective at using oxygen to produce ATP and, therefore, do more work at an aerobic level before dipping into your anaerobic production of ATP. As a side note, this is also why Mo Farah, who builds an incredibly strong cardiovascular capacity, can still generate an effective ‘kick’ to run a sub-51(!!) second last lap after running eleven and a half 64 second laps, whereas, those with weaker cardiovascular abilities do not have the phospho-creatine reserves to do this. For reference, normal people like you and me most likely wouldn't even manage a single lap at 64 seconds before completely depleting our reserves.