Simple Data Drives Behavior

How to use Heart Rate Training (HRT) to Reach Your Goals

Heart rate technology has been around for awhile now, but it is only in the last few years that it has become less of a runner’s tool, and more of a mainstream gym bag essential. With the inception of smart watches, step monitors and other tools, heart rate training has become a fitness buzzword. But what IS heart rate training, and can it really help you achieve your goals? First there is no magic tool that will instantly and without error allow you to hit every fitness goal exactly on time. But having additional data will allow you to adjust your program quicker and smarter. By providing simple data in a real time feedback loop, HRT encourages you to maximize your time and effort whether you are working out in the gym, outdoors or at home.

How do they work?
Every time your heart beats, a tiny electric signal is generated that causes your cardiac muscles to contract and pump the blood. Heart rate monitors work by measuring the electrical signal that is sent to the heart for every beat. A tiny sensor in the monitor picks up and records the signal, then transmits that signal to a database where it is converted to usable information such as time between beats, heart rate and calorie burn. This is also why different systems may produce different results. As we learn more about how the body works, and refine the calculations to include more variables like: heart rate variability, temperature, VO2max, we get closer and closer to true values for things like calorie burn.
But there are limitations.
Since all the calculations are done with regard to the general population (statistical norm), certain factors may interfere with the accuracy of the results. If you are on a medication that lowers your blood pressure or raises heart rate, although the monitor may correctly evaluate your beats per minute (bpm), you could produce results that are skewed too low or too high. For this reason, always pay more attention to how you feel rather than to charts, color codes and numbers. Use HRMs as a tool, not as a holy grail.

Which is better chest or wrist style?
Accuracy is the primary reason that chest heart rate monitors continue to be the more accurate style of monitor. Simple reason- proximity.
Chest HRMs sit directly above the heart. Ask any doctor, will you get a better reading listening to the heart through a stethoscope or by taking a radial (wrist) pulse? The electric signal transmitted from the heart is muted as it travels through the body. Factors like body mass, hydration and skin thickness can influence how the signal is read on different places on the body. Although designers and mathematicians do their best to calculate for those differences, it is unlikely that they will ever be as accurate.

Using HRM for Cardio Using a HRM for cardio has been the traditional way to utilize monitors, primarily since the differences in cardiac output are easier to see and quantify. With exertion, the heart rate increases. While resting the heart rate lowers or recovers. If tracking over time, you can see the adaptation that happens when the heart muscle becomes more efficient. The resting heart rate (RHR) drops and is less prone to huge spikes when activity increases. This is great for your cardiac health, but some people get disappointed when they are not achieving such high numbers for calorie burn. But if you know why, it should be more encouraging. Using HRT for Strength Training This is a slightly newer idea, brought into vogue by boutique fitness and classes like Orange Theory and the popularizing of things like metabolic training protocols (lifting with little rest). Although you will see lower calorie burns that what is typically returned in straight cardio sessions, the metabolic effects of this style of exercise will promote greater returns- and allow you to “look better naked”, due to the muscle-sparing nature of the exercise.

Understanding Zones Heart rate zones are generally color-coded intensity charts meant to establish a correlation between exertion and fuel source. But as discussed earlier, there are limits related to statistical norms. Rther than focus on zones, pay close attention to how you feel, and how that relates to the colors/zone you see. If you are in the gray but feel like you are about to drop- stop. If you are in the red but feel GREAT- keep going. There has been a lot of discussion about heart rate zones and what fuel you are burning in each. It has been oversimplified and often misconstrued. Time is a far more potent indicator of what fuel source you will burn than intensity, although it is related. The human body has 3 sources of energy.
Fat, carbohydrate, and protein. Typically, the body will work to burn through circulating blood sugar (carbs) first. If you have significant circulating blood sugar, this may take quite a bit of time or intensity to burn though. From there, what percentage of energy comes from each source will be largely dependent on whether you are doing aerobic (with oxygen) or anaerobic (no oxygen) exercise. But this can change inside every workout. This means that it is not necessary to do long bouts of cardio to burn “primarily” fat. You can switch between metabolic training and recovery inside every workout to accomplish the same result in a shorter duration with less wear on the joints and more muscle-sparing effects.

The REAL value of HRT Calorie awareness. Most people think of calories in the abstract. But when you begin to equate the work involved with burning a single calorie, you begin to mentally compare work-reward when choosing meals and snacks. This is the true value of heart rate training- understanding the balance between intake and output. It is difficult to justify a 350-calorie candy bar that you enjoy for 2 minutes, when you know that what it takes to burn just that small indulgence is up to an hour of significant exertion. Here is what it might take to burn some of your favorite foods*.

Some interesting equivalencies: