A short workout is almost always better than no workout at all.
NCAA runner turned high school coach Hillary Kigar has an answer for all things training—no matter how much time in a day you have to devote to your workout.
If I only have 15 minutes, is it even worth working out?
Sometimes the day has been crazy, and you just need to get out and run. If that’s the case, then get out there and get a quality 15 minutes in, and try to squeeze in some stretching. But for the most part, if you have 20 minutes or less, it can be more effective to do a high-intensity interval workout instead. There are a lot of different “15-minute workouts” out there, but look for something that keeps your heart rate high and includes a combination of cardio and strength work. Often these workouts keep you on a 30-second interval as you go from pushups right into jumping jacks, then straight into squats, back to pushups, etc. You’ll be surprised how quickly your heart rate gets up and you feel winded!