[edwinland]

I wonder if this is another proxy for Vitamin D? People who exercised regularly likely also spent more time outdoors?

[Magic Fingers]

“I wonder if this is another proxy for Vitamin D? People who exercised regularly likely also spent more time outdoors?”

I don’t think so. Many people exercise indoors (gyms), and those who exercise outside don’t necessarily do it at the right time of day on a sunny day, with sufficient skin exposed to stimulate adequate production of Vitamin D.