Dan Melfi was used to bicycling up and down mountains in his home state of Colorado when he was diagnosed with multiple sclerosis in 2009 at age 58. Now, he needs some assistance to walk—a walker, scooter, forearm crutches and, occasionally, a wheelchair. He’s a bigger advocate than ever of an active lifestyle. He goes to an MS swim class twice a week, which he enjoys because it helps him move all parts of his body without fear of falling, and he practices yoga.