Beginning in November I upped my D3 dose from 2,000 to 4,000 units per day.(flu season)
In January, early on , I ceased riding my bike, too cold. By late March and warmer weather I resumed riding my bike. After several days on the flat, I attempted the hills. Couldn’t make it up the hills for the first time ever.
Vitamin D does not promote strength. Repeated exercise promotes strength. I’ll try again in a week or so
Blustery, drizzle, and I got dehydrated sweating in the rain jacket, so my quads cramped.
Did I mention the 20-mph headwinds?
Still finished the 65-miler; but for the first time my cubs (on their respective high school track teams) beat me.
Cheers!