ERF 003: Should You Eat Back The Calories You Burn?

You go to your favorite hiit cardio class and burn 500 calories. You do your 10,000 steps and burn 457 calories in the day. You are looking to lose some fat so you are obviously exercising. You may even be tracking your calories that you're eating everyday. If you’re even doing any one of these things above, you have stumbled across the thought of “should I eat back these calories my Apple Watch said I burned?” Should You Eat Back Those Calories? Today's topic we're going to be covering is the topic of whether you should be eating back the calories you burn or not. If you've read last two or if you follow me at all, you know that I probably want you to be tracking your calories. The immediate second question I get to that is, “Well, should I be putting in the calories I burn from working out? Should I be eating back the calories I burn from my workout?” And honestly, that is a great question, especially if you don't know, because that could make a huge difference in whether you lose fat, maintain, or even gain fat. So we're just going to sit here and dive into a quick bit of how people track their calories. In a world where technology is abundant, people have all types of things that they can use to track calories now. Whether it's their phone, Apple Watch, Fitbit, the treadmill at the gym, there's so many ways you can “track” how many calories you burn. So this makes it so easy to see that, “Oh hey, I burned 500 calories when I ran on the treadmill for an hour.” “Oh hey, my favorite HIT class does roughly about 500 calories when I go there.” And while it may look sexy to see you burned 500 calories when you were working out, how accurate is that actually? That's what we're going to dive into here today. I first want to dive into the things that actually track your heart rate and track your calories. Like I said before, most people use their Apple Watch, or they use their Fitbit watch, or they even have a strap around their chest or around their wrist that tracks their heart rate. The problem with these things is, they've been shown to track heart rate, up to 95% correctly, so there's only about a 5% error there. And there's a couple of studies out there you can look at. One of them is a Stanford Medicine article published back in 2017 that showed that most fitness trackers have about a 95% accuracy rate as far as heart rate goes. So when it tracks your heart rate, it says you're 86% of your target heart rate? Normally that's about 95% right. The problem was when the fitness tracker was showing how many calories they burned, that was up to 93% wrong. So whether it's over or under, it's up to 93% wrong. So how can you use that number to really put into your diet to hopefully help you see results? Another study in February of 2019 from the British Broadcasting Corporation showed again that the heart rate monitors, show to be pretty much accurate as far as the heart rate, but most of them are up to 50% wrong in overestimating your calories burned. Think about that. 50% wrong? So when you're going into your favorite HIIT cardio class, it says you're burning 500 calories, you're only burning 250. Now I'm really not saying that's bad or good, because honestly I'm not really concerned with how many calories you burn at the gym. It starts to become a problem when you need to hit a 1500 calorie goal for the day to lose fat. Now you're asking me, “Okay, well I'm supposed to eat 1500 calories. So do I eat back the calories that I burn? Because if so, that puts me at 1900 calories a day.” So let's talk about it. If you're eating 1900 calories a day because your fitness tracker says you're burning 500 calories, but in reality you're only burning 250 calories. So you're eating 1900 calories, but you're really only supposed to be eating 1500 calories to lose fat. You're doing this five, six, four times a week. You're eating 1900 calories on the days you burn those calories.