How does this work ?

Mzmoma

Why is that when you work out it adds all the calories you lost back to your calorie counter?

Sl1ghtly

Because excersize is for fitness, and (assuming your calculations are correct) your body needs to be refueled for proper recovery and strength gains.

The weightloss deficit is still there.

rockerbabyy

because MFP calculates your deficit without taking exercise into consideration. so technically you can lose weight without exercising - but when you do exercise, you need to eat more to fuel your body and keep your deficit from getting too big