Should one replace burned calories?

Question

Question: Should you replace calories burned after exercise (specifically when you already take exercise levels into account while calculating your food goals)?

Example: I calculate my food/macro-nutrient goals by calculating my BMR using my LBM and use an activity level multiplier to come up with my TDEE which I consume 80% of in order to create a calorie deficit.

Since I am 5' 9", 150 lbs with about 16% body fat, my BMR comes out to be 1607 calories. I multiply that by 1.35 since I go to the gym five days a week to lift weights and consider that to be moderately active. That makes my TDEE equal 2169 calories. I multiply it by .8 to only take 80% of it and so, in total, I try to consume around 1735 calories.

Essentially, I want to know if I started doing cardio of some sort on any of those days (maybe high intensity interval training), would it be wise to increase my calorie intake at all if my goal is to lose weight?

Anecdote: My mom uses an app on her smartphone to track exercise and food intake. She wants to follow a consistent meal plan every week, but her app tells her after a cardio session the approximate amount of calories she's burned. She thinks she should replace all of those calories with whatever she can find, but I'm skeptical. How could one possibly plan for the exact number of calories the app is going to calculate?

Answer 1

Your answer is both yes and no. Yes, you should replace burned calories, but no, you shouldn't go above and beyond your estimated levels if you've already accounted for them.

By that I mean you have calculated out your BMR, added in your exercise levels and come out to an estimate of how many calories you should be at for a daily intake. You can adjust up or down from that number to get your weight gain/loss or to maintain.

Now, calories are NOT a zero sum game. If you eat an extra 300 calories today, that doesn't mean you're going to gain 1/5 of a pound. It's a day to day consistency that produces results. Weigh yourself at the same time under the same conditions each day, and note the trends. If the trend is going in the direction you want, keep it up. If it isn't where you want, adjust.

Answer 2

Most people don't really need any calorie replacement after workouts, and if you are trying to lose weight, it would go against maintaining a deficit. If you are really hungry a day after a workout, you could eat a little more that day.

Exceptions - If you are working out hard - and by hard I mean a long workout where you are working hard (say, 800 real calories or perhaps 1200 my most gym machines) - then a replacement drink to refill your glycogen stores is a good idea. You aren't working that hard, so I wouldn't bother.