Try this sample workout

Start on the treadmill for 5 minutes at 65% of your max heart rate. Then hop off and do 5 different strength exercises for a minute each with no rest in between.

Something like: speed squats, split lunge jumps, alternating wide/narrow stance pushups, shoulder taps and abdominal twists

After completing all 5 for a minute each, hop back on the treadmill for 5 minutes at 80% of your max heart rate.  Repeat this 3 times for a solid 35 minute workout.  Let me know how it goes.