Calorie intake when exercising

If you're following MFP's goals, eat back 50-75% of what you burn on top of the 1400. If you're following TDEE, 1400 is it because exercise is already included.

Ummm...mfp=MyFitnessPal. That's where you are dear. I suggest that you read the sticky posts at the top of this and every other forum here. They give you tons of basic info that will answer all these questions and more!

The number this site gives you does not account for any exercise; it expects you to add it in as you do it and eat those calories. So, if you're actually burning 500 and logging accurately, then you should be eating 1400 plus the 500 calories for a total of 1900. You would still be in a calorie deficit and still lose at your designated rate.

Since calorie burns are often inflated, most recommend eating a portion of those calories to account for errors. You can adjust the percentage over time to get the results you want.

Eating exercise calories will help keep your deficit from being too large which can result in losing a larger percentage of muscle mass along with fat. Plus, it keeps you fueled for you workouts.