Here you got some tips, to get fit into the routine:
Start fresh everyday: if you eat poorly one day, make sure to add the appropriate amount of cardio to your workout in order to burn off the extra calories. That way, psychologically, you start the next day at zero again. You ate a lot during the weekend, and feel lazy on Monday? Take off the bus some more blocks as usual, from work to home and vice versa.
Keep your routine exciting: boredom is one of the biggest saboteurs. Find ways to keep yourself interested in exercising. Try taking a kick boxing class, is well known that a combat class can make you burn an approximate of 600 calories per hour, instead of traditional cardio, buy a new gym outfit or fill your iPod with new workout tunes.
Pair up: find a workout partner with similar goals. If you have trouble getting motivated to workout, the guilt of leaving them alone will help motivate you. Convince your girlfriend to have a chit chat meanwhile you are working out, or to talk about last night football game with your buddy.

Sleep and hydrate: Many people do not realize that sleep deprivation and dehydration are two of the most common reasons people fall victim to cravings. Make sure to rest up and drink at least 8 glasses of water a day. Also your skin will look gorgeous!
Take baby steps: make sure to set smaller goals that you are capable of achieving. It is easier to push yourself if you feel you are succeeding.
Change your mantra: instead of saying “I don’t want to go,” say “I have to go.” This will mentally put your body on auto-pilot and make it easier to go to the gym.
After all this, you will feel so much better for sure.