Why Tracking Your Heart Rate During Your Workout Is So Important
If you start tracking your heart rate and set some heart rate goals, it could be a GAME CHANGER for your fat burn and your fitness level. Let me make this clear, I am not trying to shame this client, this discussion is a teaching tool to help all of you get healthier and fitter and MAXIMIZE your efforts. Isn't that what we all want, right? We want to get the MOST out of the time and effort we put into our workouts, right? Here is how you can do that:
On the left, is the client's heart rate tracking during a cardio workout. Notice that most of the workout time was spent in the "fat burn" zone (I wish it wasn't called this because this a COMPLETELY inaccurate account for what is happening in your body, but that is what Fitbit calls it, so we will just use that term for this demo purpose). The "fat burn zone" is basically minimal effort. You are barely out of breath, your heart rate is only increased minimally from what your normal heart rate would be if you were just going about your day. So, I would describe this as a semi-fast walk rate. Are you working out your heart and thus getting cardiovascular benefits? Sure. Are you burning fat? Nope. This minimal effort does NOT burn through the stores of glycogen in your liver and bloodstream and forces your body to transition to breaking down fat as fuel.
On the right: This is my heart rate record of my last cardio workout. Notice the top two bars, Cardio and Peak. Cardio is when your body is really starting to work hard to take in and get oxygen and glycogen to your muscles, it also, if you spend enough time in this zone, will deplete your liver and blood sugar stores of sugar, this is when your body is forced to turn to convert body fat into sugar to keep you going. The peak heart rate is where you transition to anaerobic fitness. Your body is having to tap into glucose because there is not enough oxygen getting to your body anymore. This means your metabolism is amped up like crazy, your body is frantically pulling glucose from your system. The wonderful thing about getting into your peak heart rate (I like to have a guideline of spending at least 10 minutes in this zone total for a cardio workout) is this thing called excess post oxygen consumption EPOC. This means that because you so depleted your glycogen stores and your oxygen, your body has to "make up for it" by working hard for up to 48 hours to replace those things. This means your metabolism is revved up for up to 48 hours! So, let's compare.
Would you rather have your metabolism revved up for ONLY the duration of your workout (fat burn zone) or do you want to spend up to 48 hours past your workout with a revved up metabolism (cardio and peak zones)?
YES, right answer! We all want to burn more for longer and not have to workout longer to do it! So, how do you do that? You ratchet up the INTENSITY of your workouts. You get that heart rate into the peak zones for as long as you can tolerate. If your cardio heart rates look like the one on the left, you are not pushing yourself past your comfort zone. The heart rate zone called the “fat burn zone” on the Fitbit does not mean you are burning fat. It is actually the opposite. You are not pushing hard enough to deplete the glycogen quickly. This means you have to workout for a much longer period of time in this heart rate zone to deplete your glycogen stores. This is very common for people who workout. You know why? Because it's VERY uncomfortable to get into a cardio zone and CRAZY uncomfortable to get into the peak zone. In the cardio zone, you should be out of breath, but still can complete sentences, if with maybe a little effort. In the peak zone, you should be gasping for air and cannot manage anything but grunting or a four-letter word. That's the difference.
Bottom line. Get your heart rate into the "this sucks” zone as long as you can tolerate it during your cardio workouts. It will pay dividends with your overall fat burn and how fit you get faster to maximize the time you are putting into your workouts. What is great about this strategy is that you don't have to workout longer, only harder.
