The Ashland Farmers Market will hold a health and nutrition day Saturday. The day will feature a guided family-friendly bike ride departing at 9:30 a.m., and an intermediate 10- to 15-mile ride departing at 10:30 a.m., both leaving from and returning to the market at 125 Front St. In addition, students from the Jae Hun Kim Taekwon-do Institute will do a live demonstration at 11:15 a.m. at the Old North Music Stage, and there will be yoga, tai chi, and other fun activities and presentations focused on physical and nutritional health concepts. The market runs from 9 a.m. to 1 p.m. For more information, visit www.ashlandfarmersmarket.org. Full story for BostonGlobe.com subscribers.