To make the most of your time to work out, try a circuit. Circuit training is cardio and strength training all in one, much of it with very high intensity, to get the most out of your workout. Set up a circuit that includes a cardio station ( a jump rope or trampoline, or even a running in place spot), a strength station (with weights or body-weight station), and a core-inspired station (a mat, ball, or bosu). Rotate between the stations 3 times, spending 2 minutes on each. As you get stronger, add more circuits. Your initial circuit will be a 20-25 minute workout, and you can keep adding to it for more time and intensity. With a larger circuit, add a 20-30 second recovery period in between, and you'll end up with a 30-45 minute full body cardio wear-me-out workout.
Here is an example of a beginning circuit:
Warm up with a march or step touch sequence for 2 minutes.
1. Run in place 2 minutes
2. Use a hand weight. Squat down to put it on the floor, Stand up, squat back down lift the weight (straight back, head up) up, straighten the legs, pull the weight above your head. Repeat for 2 minutes.
3. Pull your arms down as you lift one knee at a time, pulling the abdominals in and exhaling on each rep. Continue with one knee for one minute, and then the other knee for one minute.
Walk around for 20-30 seconds and start the process again.
Do the circuit 3 times.
The final walk should bring the heart rate down. Follow a stretch or yoga routine for 2-5 minutes, and you're done.
That's for starters. The possibilities are endless. You won't get bored, you can design it yourself, and you'll get in tremendous shape. Like a circuit? Do it every other day for a full body workout, or just a couple of times a week for a change to your routine. The body likes to be challenged with something new, and will thank you by changing it's shape for the better. You may also find some new muscles that haven't been challenged before. Bonus!