This simple program will help you make the most of a short workout by improving heart health and endurance. Try it with your favorite cardiovascular activity.
1. Run (or bike or swim or row) lightly for 30 seconds.
2. Run moderately for 20 seconds.
3. Run at top speed for 10 seconds. Repeat the sequence 5 times, then rest for 2 minutes and repeat the sequence 5 times again. This routine takes 12 minutes to complete. If you are already in good shape, add another round of 5 repeating intervals. The next day, try a lighter exercise before trying 10-20-30 again.