To build muscle fiber you need to train hard enough to create a need in the muscle to grow strong and larger. That doesn't mean to pain necessarily, but to fatigue. Burning indicates fatigue in the muscle fibers and energy being used up! Stay strong...stay motivated!!
Had a field trip at school today which was really fun and it also means more walking, so more calories burnt! Ate about 400cal today which isn't the best but I guess isn't too bad. Most of the time I go for trying to burn off at least 1100 more than what I eat, which I did today. Omg so glad I have a Fitbit so I at least have an estimation of the calories I burn.