Exercise for performance or stress reduction?

The recent debate between high intensity interval training (HIIT) or moderate intensity continuous training (MICT) focuses on fitness goals that incorporate time efficiency, performance enhancement and stress reduction. One’s goals then can guide a choice in fitness regimen. In general, HIIT allows for a more focused high intensity less time consuming approach to achieving better overall strength and performance goals over time. MICT on the other hand is less intense, more time consuming and better able to alleviate emotional stress.

These differences were highlighted in a recent Nature neuropsychopharmacology article which concluded that stimulation of the mu opioid receptor system by acutely increased release of endorphins in HIIT actually creates a more immediate sense of stress and negative emotionality whereas MICT creates a slower more extended release of the same endorphins producing a sense of decreased emotional distress after exercise. These changes were measured in intervals during and after each exercise regimen by PET scan and stress survey scales.

The exercise regimens consisted of 5, 30 second maximal effort stationary biking sessions (each separated by 5 minutes of rest) as compared to 60 minutes of moderate effort stationary biking.

The application of these approaches to health maintenance is important. As a general Internist taking care of many middle and retirement aged adults, we recommend moderate intensity cardiovascular fitness associated with stress reduction and flexibility that go a long way toward optimizing health. Younger people can consider or combine these approaches as meets their own needs as well.