It’s come to my attention that pretty much all my posts so far have been nutrition-related and that I haven’t written a great deal on exercise. Point taken. As a personal trainer, a large chunk of what I do for clients involves determining an exercise regimen that will yield the best results. Part of that regimen includes designated time for cardiovascular exercise. But how much, how often, and how intense should that cardio be?
I’m fully aware there are a huge amount of people, namely women (no offense), who subscribe to the theory that cardio and ab exercises will yield maximum results for their physique. They’re under the impression, for whatever reason, 90 minutes of cardio and crunches every day will have them looking amazing. Let’s just nip this one in the bud right now. They’re completely wrong. If all you’re doing at your gym is cardio and abs, I would highly suggest canceling your membership now because honestly, you’re going to eventually wind up doing yourself more harm than good.
There are at least a few cliched quotes that come to mind when thinking about cardio. “Work smarter, not harder,” is one of them. The other is, “less is more.” Let me explain.
Work Smarter, Not Harder
Working in the corporate world for so long, I bet I’ve heard that ridiculous quote a million times. However, it does apply to some things in life. Cardio happens to be one of them. Before you can work smarter, though, you have to at least have an idea of what is it cardio is doing for you.
A lot of people do cardio without any set plan in mind, thinking they are somehow magically destroying fat. Depending on the circumstances, that can be partially true. But if you do it wrong, you may only be exercising your heart muscle, which is good, or inadvertently be contributing to the loss of muscle. Bad bad bad! Which one of these things are you doing? Well, that depends on your heart rate.
The first thing you must do when determining how fast your heart should be beating during cardio is to figure out your maximum heart rate (MHR). There are a lot of ways to calculate this number, but the easiest one to determine a baseline is this: 220- your age = MHR Example: 220- 31= 189
That would be my MHR, and what we’ll use as an example for the rest of this post. Now that we’ve determined the maximum heart rate, you have to choose a percentage of that MHR you want to be in to achieve certain goals.
Most people’s goal with doing cardio is fat burn. Other people’s goals are more conditioning related for sporting events. Whatever your goal is, there is an ideal heart rate you should be living in to achieve that goal.
55% MHR is the “fat-burning zone.” This is generally recognized as the best place to be if fat loss is your desired goal. So, using that calculation above, 55% of my MHR would be around 104 beats per minute. This is a fairly low heart rate, and for that reason, this type of cardio has almost zero effect on the heart and lungs.
Additionally, in order to achieve any substantial benefit from this type of cardio, you have to do it for longer periods of time. 30 minutes to an hour is a good baseline, but too much of it can weaken your muscle and sometimes cause muscle loss. When you hear the term “steady state cardio,” this is the type of cardio that is generally being talked about.
When you hear the term “cardio,” however, the actual definition of this means you’re training somewhere in the 75-80% MHR range. Once again using the calculation above, that would put me at around 142-151 beats pers per minute. This type of cardio conditions the heart and lungs, and is a good way to better strengthen your VO2 capacity. That’s just a fancy term for how well your heart and lungs use oxygen.
The body’s primary fuel for this type of cardio is the glycogen stores in your liver and muscles, which means you had better be properly fueled before doing it. As I explained yesterday, once the glycogen stores run out, your body starts looking to use free amino acids in your bloodstream and if there are none, it will cannibalize your muscle. Yet another reason to make sure you include plenty of protein in your diet.
Reading what I just wrote, you may deduce that you should be doing either one or the other of those kinds of cardio. But wait, before you put your earbuds in and run off to do long-form cardio at a lower heart rate, think about this. Your heart is probably the most important muscle you have. The obvious reason is that without it, you wouldn’t be alive.
The less obvious reasons are that a strongly conditioned heart makes nearly every other part of your body run better, from digestion to recovery from vigorous exercise. A strong heart also makes your body burn fat at an accelerated rate while at rest. This is the part where working smarter, not harder comes into play.
If you haven’t read my Basal Metabolic Rate post, please do so now and determine yours. If you’re eating correctly and getting the proper amount of calories for your goals, which I hope you are, you’re almost completely eliminating the need for that 55% MHR cardio. In fact, if your calories are right and you’re doing shorter durations of that 75-80% MHR cardio, not only are you strengthening your heart and lungs, you’re practically guaranteeing you’ll be burning more fat than the person who is overly relaxed with their diet and does endless amounts of “fat burning” cardio.
I try to give all my clients the proper nutritional guidelines so at the most they only have to do cardio 2 to 3 times a week, and I rarely ever have them do long durations of it. It’s boring and unnecessary. Eat right. Lift weights like a beast. Condition your heart for optimal fat burning. Smarter. Not harder.