If working out at the end of the day is too hard then try switching to the beginning of the day. You'll be surprised how energized you'll feel. Then of course you may face the factor of how to motivate yourself enough to roll out of bed and just do it. I have to agree with NaM once you start after about the first month or two it becomes a habit and you won't even realize. Another way of approaching it is to start gradually, after having her baby my bff kept the extra weight on for a year plus. One day she promised herself to do 1 hour of cardio and 30 minutes of strength training. She kept the promise for a week, then kicked up a notch for the next week, then the next and so on. She also switched it up so she didn't get bored. Cardio was riding a few miles, or playing tennis, or taking a cross training class, or spinning. Always something different. It also helps to have a friend with you. I love to workout so I bargained with her she would bear me taking her to yoga if I went with her to workout. But the initial motivation/push has to start with you.