Calories are a measure of energy, typically used to measure the energy content of foods and beverages. Your body uses the calories that you eat and drink for essential functions, such as breathing ...

Fitbit's calorie tracking feature isn't very accurate ... the conclusion is "discretion should be used when considering the use of Fitbit devices as an outcome measurement tool in research or to ...

Burn more calories ... measuring your progress — if you stick to the same machine at the gym. But unless you're riding a well-calibrated stationary bike, you're unlikely to get an accurate count.