Effects of Light and Exercise on Human Circadian Rhythms and Performance

Effects of Light and Exercise on Human Circadian Rhythms and Performance

Both light and exercise are effective countermeasures for space and ground-based crews for circadian phase resetting and alertness levels. The investigators propose to test the combined effects of these two countermeasures to determine whether adding exercise to light stimuli will further improve circadian phase resetting and alertness.

Inclusion Criteria:

• healthy by history, physical exam, laboratory studies of blood and urine, and psychological screening
• moderate-intensity exercise for at least 150 minutes per week

Exclusion Criteria:

• color blind
• no prescription medications, except hormonal birth control in females