Strenghten your quads

In an article on MedScap News - "Quadriceps Strength Linked to Lower Risk for Symptomatic Knee Osteoarthritis"

"Knee...OA (Osteoarthritis) is a major public health concern worldwide and one of the foremost causes of chronic disability in older adults," write Neil Segal, MD, MS, from the University of Iowa Hospitals and Clinics in Iowa City, and colleagues. "There is evidence that muscle dysfunction is involved in the pathogenesis of knee OA."

Plain language - strengthen those quads if you want to keep your knees safe and sound