After coming back to busy Harvard life after a month-long J-term, many of us are going to find it difficult to get back into the swing of things—classes, clubs, friends, not to mention hitting the gym. However, 15 minutes is all you need to get in a good calorie-blasting workout. Try this cardio routine:

• Stretch for a minute. This helps warm your muscles up so you don’t strain anything.
• Jog at the speed you would consider your 60% for three minutes.
• Switch to your 90% speed for 90 seconds.
• Go back to your 60% for 90 seconds.
• Repeat these two speeds for a total of three times.
• Stretch for a few minutes after you are finished running to loosen your muscles up and prevent any injuries.

And remember, cardio is great for overall health. Not only does it burn calories, but it also strengthens your heart and lungs, helps your immune system. You’ll have more energy and sleep better—advantages that every girl at Harvard could use!