Weight loss can be very weird sometimes. After most of a year of 1lb/week loss at the same exercise and intake level, it leveled off for a significant period. This happened as I was starting to do half marathon training so I was like OK fine I'll ease off the deficit for improved recovery and then resume post-race. But then the loss started up again? I'm working out more, but I guarantee I am not working out 1,000 Calories per day more as this would suggest.