Would you work out an hour or so and have a burger afterwards? Probably not.
Would you skip the gym and feel so bad and have a burger instead? More likely.
When you start working out you don't want to ruin what you have achieved by messing up with your alimentation. Working out helps to control your food.
If you dont feel working out, remember this - you will never regret a work out you will only regret to not go. You cannot deny the euphoric feeling while and after exercising so on lazy days try to remember this.
And if you still look pretty after a work out, it means that you haven't worked out enough. You have to be sweaty, salty, ugly and have jelly legs feeling. Feeling this? Well done!