Exercise Activity Thermogenesis (EAT) is probably the first thing that people think of when they think about their daily calorie expenditure, and is almost always the first factor that people consider when they are looking to manipulate their expenditure up or down. This is, however, not a great idea.
EAT will generally come to 10-30% of your TDEE depending on your overall activity levels (though for typical modern exercising individuals who exercise for an hour 3-4 times per week this figure is going to be somewhere around the 10-15% mark) and the particular mode of exercise that you partake in. For example, resistance training burns perhaps 100-300 calories per session depending on your volume and training density (reps/sets per unit time). A high-volume session involving squats, deadlifts, leg presses and lunges, for example, will burn somewhere around the higher end, whereas a heavy squat session alongside sets of two on the deadlift may be equally tiring but won’t actually burn that many calories because most of the time is spent resting.
Note: The same principle applies to HIIT training which may be beneficial for other reasons, but isn’t great for increasing calorie expenditure because you spend a good chunk of your time resting.
In terms of increasing calorie expenditure, by far the most effective manner is by engaging in cardiovascular activity for prolonged periods of time, but even then, a 60 minute moderate intensity session (you cannot perform high intensity exercise for 60 minutes) would be unlikely to burn more than 600 calories, which equates to around half a pint of high quality ice cream and around 15% of a typical male’s daily expenditure. EAT can absolutely make a difference to your TDEE, but how large that difference is tends to be overestimated, especially seeing as increases in EAT tend to lead to fatigue, which will negatively impact our next factor.