You went for a hard run, and your smartwatch buzzed to tell you that you burned 500 calories. Because you worked so hard, you decide to reward yourself with a 400-calorie muffin. You are still in a 100-calorie deficit for the day, right?
Wrong. You likely just erased your entire weight loss deficit for the day. This is the single biggest mistake active people make when trying to lose weight.
Eating calories is incredibly fast; burning them is incredibly slow. It takes about 60 seconds to eat two slices of pizza (600 calories). It takes the average person about an hour of continuous, exhausting running to burn those same 600 calories.
Because it takes so much physical effort to burn a small amount of energy, trying to use exercise as your primary tool for weight loss is a losing battle. Diet drives weight loss. Exercise drives cardiovascular health and muscle growth. Keep the two separated in your mind.
Smartwatches and cardio machines at the gym are fantastic motivational tools, but they are notoriously terrible at doing calorie math. Studies have consistently shown that fitness trackers overestimate the amount of calories you burn during exercise by anywhere from 20% to 90%.
If your watch says you burned 500 calories, you may have actually only burned 250. If you "eat back" 500 calories based on that watch reading, you are suddenly eating in a calorie surplus and will actually gain weight despite working out.
To lose weight reliably, do not link your daily food intake to your daily gym session.
Disclaimer: The information on this website is for educational purposes only. It is not meant to replace advice, diagnosis, or treatment from a medical doctor.