https://onlinelibrary.wiley.com/doi/10.1111/obr.13099
Calories are units of energy, as we exercise we use up energy to contract the heart and muscle and therefore the more we contract the muscles and heart the more calories we burn. When we do cardiovascular exercise we have two main choices to break up the exercise time. We can either work at a moderate pace non-stop for the duration of the exercise time (moderate intensity continuous exercise) or we can split the exercise time into small chunks where we work hard followed by a short break and then repeat (sprint or high intensity interval training). This study looked at how doing either moderate intensity continuous exercise (MICE) or High Intensity Interval Training (HIIT) effects the amount of calories burned. They found that even when the distance ran/cycled and time exercising is the same HIIT burns more calories due to a large amount of calories burned after exercise (excess post exercise oxygen consumption (EPOC)). Therefore, if you are trying to lose weight and increase how many calories you burn then perform high intensity interval training.
