Regulating light exposure is the strongest zeitgeber and should be addressed first to align sleep-wake cycles and exercise.

“light, and when we view light is the primary way in which these genes and the clock systems of our body get organized or entrained, meaning matched to the outside light dark cycle.”

“I'm biased 'cause I believe that light is the strongest time giver. [...] That's why I think we need to regulate this first and everything else fits.”

“View 10 to 30 minutes of bright light, ideally sunlight, within an hour of waking assuming that you're waking early in the day especially.”

“it turns out that light exposure to the eyes at particular times of day really sets the whole body and brain into particular rhythms that you know explain why I was a little depressed when I was in graduate school staying up all night doing experiments and I'd sleep much of the day and feel like I was getting 8 nine hours”

“So many people find that they need to use sunlight simulators in the form of particular lights that were designed to simulate sunlight.”