Why You Should Forget About the Fat Burning Settings

gym cardio machines

I absolutely love exploring program settings on cardio machines when I’m feeling less than inspired to sweat it out at the gym. Who wouldn’t? You answer a few questions, plug in a few numbers, and the machine takes over. It’s almost like having a personal trainer looking over your shoulder to choose the perfect options! Except, not exactly.

While the program settings can provide variety, the machine doesn’t know you or what you need. Ultimately, settings such as “Random” and “Interval” can be helpful to ensure you are cycling through different intensities while you binge-watch “This Is Us,” but you should steer clear of the “Fat Burning/Fat Burn” settings, for sure! Here’s why.

The Machine Doesn’t Know You

If you choose any variation of the “Fat Burning” setting, the machine needs to determine your personal fat-burning zone. Your fat-burning zone, usually defined as 60-75% of your max heart rate, is calculated by the machine. Then it monitors your heart rate and automatically adjusts the intensity of the workout to keep you between the two numbers. Each machine is different in the calculation it uses, but most use a variation of subtracting your age from 220 as a way to predict your max heart rate. But here’s a news flash: Your max heart does not necessarily change each time you blow out the candles on your birthday cake! In other words, the calculation the machine uses to put you in this zone may be flawed from the get-go.

Your Heart Rate May Not Be Right

Establishing your fat-burning zone depends on knowing your heart rate during the workout. Then the machine can adjust various options (incline, speed, resistance) to make the workout harder or easier to keep you in the right zone. So, it must know your heart rate with certainty to work. Unfortunately, heart rate sensors in the handles you’re using might not be providing accurate data. Sweat may cause your hands to slide around on the handles, thus giving a false reading. And residue left on the sensors from prior use or cleaning agents can also decrease the validity of the heart rate reading.

The Fat Burning Zone is Misunderstood

Finally, let’s discuss the most important reason why you should just avoid the “Fat Burning” setting altogether: It’s based on a theory that’s not necessarily efficient—or accurate.

Fat burning zone is based on the thought that your body will burn more fat at a lower intensity, which will accelerate your fat-loss. This means the machine attempts to keep your heart rate at a lower intensity level throughout the workout to ensure you’re maximizing your “fat-burning” ability. While it’s true that the body utilizes a greater percentage of energy from fat at lower intensities (<50% of your VO2max) versus high(er) intensities (>70% VO2max), the higher the intensity, the more total calories you will burn. And you guessed it: You end up burning more “fat calories” in the same amount of time if you increase the intensity a bit. You would need to be on the treadmill for nearly twice the amount of time at the lower fat burning setting to achieve the same total caloric expenditure. Who has time for that?

The Final Word

Please know, I’m not suggesting you never work out at lower intensities or that this type of training might not be a great place to start and build. Low intensity, steady-state training is valuable for a variety of reasons. But it’s important to know what is (and is not) happening when we blindly follow the advice of a machine! The “fat burning” setting is ultimately misleading, and may limit your progress. Many people use the setting for long periods of time only to end up disappointed they didn’t get the results they wanted. Here’s my advice: Ditch the pre-settings on the machines, grab a trainer for a session or two, find out what a great cardio plan looks like, and hit manual the next time you jump on the elliptical!

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Shannon Fable, 2013 IDEA and 2006 ACE Instructor of the Year, is the VP of Fitness Programming for the FIT4MOM® franchise. For more than two decades, she has helped impressive brands such as Anytime Fitness, Schwinn®, Power Systems, ACE, Silver Sneakers, and BOSU® as a fitness business and programming consultant. An experienced educator, freelance writer, and certified Book Yourself Solid® Business Coach, she helps fitness entrepreneurs navigate the industry and make more money. Fable serves as Vice Chair of the ACE Board of Directors and is the founder and co-owner of GroupEx PRO®, a cloud-based group fitness management tool.