"Gym Etiquette Flowchart: See someone you know? You're covered with sweat? Don't panic," by Daniel Engber, Josh Levin, Jenny Livengood, and Melonyce McAfee. Posted Wednesday, Jan. 19, 2011.
"Exercise Time Warp: I spent a week with Jack LaLanne, Jane Fonda, and Jillian Michaels. Who's the best fitness guru of them all?" by Emily Yoffe. Posted Wednesday, Jan. 19, 2011.