That's great! One other thing I'd recommend is that you work out early in the morning if at all possible. Actually, I'm not a physical specimen but I've learned a few interesting things over the years. I'm using this Lenten season to work my way back into playing shape for a 35+ men's hockey league in my area, and I can offer a few tidbits from my informal "training" in the past:
1. Work out early in the morning. It helps get your metabolism up and helps you feel energetic all day long.
2. Related to the previous point ... Give yourself a full 8 hours to sleep every night, even if you find yourself waking up on your own with less sleep.
3. Combine #1 and #2 and a harsh reality sets in. If you work during "normal working hours," you'll find that you have to get to bed no later than 9 PM to get up by 5. If you need to get up by 4 to get a workout in, you have to be in bed by 8 PM. This relates to #4 below.
4. Go to bed at the same time every night, to the extent possible. And schedule as much of your regular sleep as possible during night hours. I've found that there's a huge difference between the quality of 8 hours of sleep starting at 9 PM and 8 hours starting at midnight.
5. Do exercise that you enjoy, not just exercise for the sake of doing it. You'll find it easier to stay committed to it.
6. Incorporate prayer into your physical activities. Make all of these difficult things a well-intentioned sacrifice to God.
7. Watch what you eat, but don't cut anything you like out of your diet completely. Even the most unhealthy food in the world is probably OK once a month.
8. Never step on a scale unless you're at the doctor's office. There are two reasons for this: (a) you're not trying to lose weight (you're trying to live better, and any weight loss will be a natural result of this); and (b) you may end up gaining weight after a while once your muscle tone starts to improve.
9. Make your exercise life a priority, not something you work into your schedule around other things. You'll be amazed at how much of the "clutter" in your life is completely meaningless once you do this. You won't have time for a lot of things that may be part of your daily routine, but you'll also find that these things aren't important anyway (watching television or surfing the Internet for long stretches of time, for example).
10. Trust me on this one: A cheerful, positive outlook will go a long way towards helping you along in this.
Good luck! I'm off to bed shortly because it's 9 PM right now here on the East Coast!