3 Surprising Facts About Heart Rate Tracking

Heart rate tracking is much more popular now that technology makes it super easy to monitor 24-7. Trackers like Withings’ Steel HR, for example, allow you to literally wear your heart on your sleeve: the rate is displayed right on the watch face so you know exactly what your ticker’s up to at any given moment. RELATED: 5 Tips for Heart Health Having that information can provide you with plenty of insights into your health, but first, you’ve got to know how to interpret the numbers. Here are a few surprising facts about heart rate tracking that’ll help you get started, so that you can start to convert all of that data you’re collecting into action. 3 Facts About Heart Rate Tracking 1. Your resting heart rate (RHR) reflects your fitness level (and overtraining). Wearing a fitness tracker throughout the day when you’re inactive will help you gauge your resting heart rate (RHR).  (Bonus: Withings’ Steel HR has the longest battery life of any tracker on the market, so it’ll stick with you all day!) A lower RHR can indicate good overall cardiovascular health. If you’re overweight and/or out of shape, your RHR may be too high and you will want to incorporate more regular exercise to bring it down. On the flipside, if you’re involved in an intense training regimen, your heart rate may stay elevated too high above its normal resting level if you’re pushing like crazy and not allowing for recovery time. So you can use some simple RHR tracking measurements to avoid overtraining (and potential injury). 2. The fat burning zone is probably a myth (or at least isn’t worth stressing over). In the past, many people used heart rate to calculate what was referred to as their “fat burning zone.” Here’s the thinking: At lower workout intensities, the body burns fat instead of carbs, whereas at higher intensities, it may burn more carbs first. So, to burn more fat, some trainers advised sticking to the lower heart rate zone. However, current thinking and research tends to show that whatever your body is burning for fuel, it’s calorie expenditure that really matters, and working out at 60-75 percent of maximum heart rate will burn less calories than 75-85 percent. RELATED: Will Exercising on an Empty Stomach Help You Lose Weight? 3. Tracking your heart rate during a workout can help you push harder. That doesn’t mean low-intensity or high-intensity is better than the other, you should just know that if you’re working out in a lower heart rate zone, using LISS Training, for example, you’ll want to schedule longer workouts. A vigorous HIIT workout at 80 percent maximum heart rate can be shorter and deliver the same results. The key: Use your heart rate tracker to make sure you’re working as hard as you want to be. If it’s LISS, don’t drop into a resting zone. If you’re trying to get in a quick HIIT session, glance down at the Steel HR on your wrist periodically to make sure you’re really pushing to your absolute max in every interval. In the end, understanding and utilizing the numbers will be one small piece of getting the most out of both your workouts and an overall active lifestyle. This blog post was created in partnership with Withings. Photo: Withings

Will Exercising on an Empty Stomach Help You Lose Weight?

Q: I’ve heard “fasted cardio,” exercising on an empty stomach right when you wake up, results in more calorie burn. Is it true? A: Exercising on an empty stomach is a topic not all experts agree on, and the science on fasted cardio is not totally clear. (Nothing is simple, I know!) However, there’s a lot of evidence that you can use to determine if the approach is right for your body. First, you’ve got to understand how food fuels sweat sessions. Carbs are the body’s preferred source of fuel for energy (while protein is used for muscle growth and repair). The body first turns carbs into glucose, which your body can use immediately as fuel. Then, it stores any excess as glycogen. During exercise, when no glucose is available (meaning you haven’t just eaten), it turns to the stored glycogen for fuel, first. When the glycogen is gone, it turns to fat.  (This isn’t a perfectly linear process. At lower workout intensities, it may use more fat for fuel, hence the famous “fat burning zone.” Using more fat for fuel doesn’t necessarily lead to more fat loss, though, since calorie burn is so much lower when you’re working out at that intensity.) The Argument for Fasted Cardio Proponents of fasted cardio argue that if you exercise right when you wake up, before eating, your glycogen supply will be low, since you haven’t eaten since dinner the night before (unless you had a midnight cupcake…whoops!). Without enough glycogen for fuel, they say, the body will start burning fat sooner, since it’ll need it to get you through the workout. Some small studies support this, like this one from 2013 that showed exercisers who skipped breakfast burned 20 percent more body fat (that day) than those who ate before hopping on the treadmill. RELATED: 7 High-Protein Breakfast Recipes for Morning Energy The Flipside However, a 2014 study in the Journal of the International Society of Sports Nutrition looked at the results of fasted cardio over a much longer period of time. After a month, researchers found no difference in body composition (in terms of weight, body fat percentage, waist measurements, etc.) between members of groups that ate before exercising and those that ran on empty. Fasted cardio doubters also argue that there’s no way to know when your glycogen stores run out, so even if you run in the early morning without eating, you may have enough left from the night before, meaning you won’t burn more fat at all. And depending on how long and intense your workouts are, you may find your performance suffers if you don’t fuel beforehand. If you’re running 12 miles to train for a race, for example, or lifting heavy weights, your body will likely need the fuel to keep you moving. RELATED: This Celeb Trainer Eats Chocolate Chip Protein Cake Before Workouts The bottom line Like with many things, I recommend experimenting to see what feels good for your body. If you wake up and feel great doing 45 minutes of cardio on an empty stomach and are seeing healthy weight-loss results, keep it up. Just make sure you get some protein and carbs in soon after you’re finished. (Smoothie, anyone?) If you run on empty and feel like totally depleted after 10 minutes, it’s probably not the approach for you. And in general, if your workouts are long, fast-paced, or include high-intensity intervals or heavy weights, it’s a good idea to eat before. Check out this post for my recommendations on the best pre- and post-workout snacks, and you’ll be ready to move.