Let's face it, if you don't get your exercise in by 2 p.m., the window of opportunity begins to close. Not to mention after a long day of work, or work and kids, who has the energy?

How about committing to three days of the week, getting it done in the morning, and one day on the weekend? If you have a commute or something that makes it unrealistic in the morning, do your workout at lunch. Who cares if you get sweaty?  Eat a nutritionally-filled smoothie and bust it out for 30 minutes at lunch.

I find it can be overwhelming to try and do both cardio and lifting each session, so just pick one and then combine the two once during the week. Here's a sample schedule.

Monday: Thirty minutes of lifting 
Do exercises that combine upper and lower body muscles (i.e. squat with a bicep curl to a shoulder press). Write out an 8-exercise circuit in your exercise notebook, and get it done without resting. Then rest for one minute in between circuits, and try to complete the curcuit 2 or 3 times. Put your music in your ear and don't look up.

Wednesday: Cardio 
Sweating and getting your heart beat up is all you're worried about. Jump on the treadmill, or elliptical, and do 20-second sprints every 2 minutes. Increase your incline and resistance as time goes on, and make the last 8 minutes of your 30 really challenging. If you do the math, that's only 4 really hard sprints. So get that music pumping and fire up.

Friday: Lifting and cardio
Throw in some jumps and hops into your lifting routine and make your circuit a combination of strength and cardio.

If you feel inspired on Tuesday and Thursday then stretch. Just go into the gym (or your living room or office) and take some deep breaths and stretch for 20-30 minutes.

On the Weekend: Do whatever you feel inspired to do
Try and make this your longest, most rigorous workout day of the week. There is more time on the weekend, so you have an opportunity to get creative. Go with a friend for a long hike (make it harder by wearing a light pack or carrying 2 lb weights), take a bike ride, or try that rad new boot camp class you've been hearing about.

This is one of the only times I think it's best to not make a plan and not think too much! Just get to work, and if you can solicit someone in your office to train with you, it's good to have the inspiration and support. Oh, and hang a phrase or picture on your fridge or cubical that will help you stay true to the course. One thing I know for sure is that consistent exercise is a huge key to weight loss and management.