2 Reasons Your Cardio’s Not Working for You Anymore
I see the same people on the same cardio machines day after day at my gym. (And I don’t just mean they’re always on the elliptical or whatever; they’re literally on the same machine! As in, the woman with the purple running shorts is always on the machine that’s fourth from the end.)
I think it’s because we’re so busy that we tend to put as many things as possible on “autopilot” so that we don’t have to think about them. Frees up our brains to deal with all the other shit on our plates.
So having your workout on autopilot isn’t such a bad thing actually. It means it’s a habit, which is exactly what we want.
Because when it comes to healthy habits, consistency is everything.
Ah, but there’s one problem with that; if you do the same thing over and over again the law of diminishing returns is gonna land you smack dab on a plateau and leave you there wondering why the hell you can’t seem to lose weight (or run faster, or whatever it is you’re trying to accomplish).
There are two very important reasons why you absolutely must change up your workouts from time to time:
- Your body adapts – and that’s a very good thing! Our bodies are these amazing, efficient machines. No matter how out of shape you may be (this from a woman who was morbidly obese for 20+ years prior to losing 120 pounds and then became a marathon runner and competitive bodybuilder) your body will respond and adapt to exercise. It wants to move! That’s what it was designed to do. Cardiovascular training of any kind stresses and strengthens the heart. It’s a muscle, after all!
A stronger heart muscle is a more efficient heart muscle. And a more efficient heart muscle uses less energy than a less efficient heart muscle. Guess what that means? Yup, diminishing returns. As in, the stronger your heart gets the more you’ve gotta up the ante on your workouts to get equal (or hopefully improved) benefits over time.
Here’s how I see this in my own workouts: I use a heart rate monitor nearly every time I do cardio. (I’m a numbers geek; I like to see what’s going on in there!) What I’ve noticed is that if I do exactly the same treadmill run for several weeks, my heart rate goes down each time I do it. That is to say, my heart becomes more efficient at meeting my body’s demands for energy and can provide the same output (running speed) with less work on its part (slower heart rate).
It never ceases to amaze me how our bodies respond in this way and it’s why I always say: “Our bodies will do exactly what we train them to do!”
But the downside of this incredible system is that we’re gonna stop making progress if we keep doing the same thing over and over again. In fact …
- As your weight goes down, so does your calorie burn. It’s kind of a cruel trick, but moving less mass (i.e. the smaller body mass you now have because you’re exercising regularly) requires less energy (calorie burn). For example, a 140-pound person walking one mile at 4mph will burn 80 calories. A 250-pound person walking that same mile at the same pace will burn 142 calories. That’s 78% more!
It really is all about physics. The equation boils down to your weight X distance = energy used. This means that, as your body weight goes down, you must walk (or run … or elliptical … or cycle … or whatever) farther and/or faster to get the same result. The good news is that speed becomes easier as you get smaller. Herein lies the magic of HIIT, or high intensity interval training. It’s an excellent way to keep your calorie burn high without spending all day bouncing up and down on the elliptical.
Hanging out on the same machine, doing the same workout several times each week will leave you stalled, I guarantee it.
Your magical, mystical body is doing its darndest to become healthier and more efficient. Yay! But all that adapting means that you’re burning fewer calories so you’ve gotta boost intensity to keep making gains.