David Duchovny avoids "electric light".
'The X Files' star is convinced artificial lighting messes with "our sense of mind and body" so he has adopted a daily routine that makes sure he doesn't have to hit the light switches at any time - with the actor admitting he gets up at sunrise and goes to bed as soon as it gets dark.
He told The Sunday Times: "Because I like to get up so early, I go to bed early also. I feel electric light has really [messed] with our sense of mind and body, and that we were made to hide in the cave at night from predators and wake up with the sun, so I try to do that. Constitutionally, I feel like that works for me."
David also thinks getting up early helps him be more productive because he feels more creative at first light.
He added: "I like to get up at dawn because those are my best thinking and writing hours. I love the sunrise but it also means I can get some work done before the sun gets too much. That's the best time of the day for me.
"I have a coffee that makes me think I'm brilliant for 10 minutes and that's all I need to get going."
The actor also stays fit and healthy by sticking to a routine of Pilates, yoga and weight-training. In a previous interview with Men's Health magazine, David explained: "I do a combination of a lot of things. I like Pilates a lot. I swim, I do a little yoga, I cross-train with weights - but not heavy weights.
"For cardio, I box, I play some tennis. I'm always trying to play a game rather than just trying to get fit. I'm always trying to be in a position where I could pick up a tennis racquet and play, rather than pick up a tennis racquet, play, and hurt myself for a month."