Research points to even more health benefits of walking, from the Harvard Health Letter

Walking is one of the simplest and easiest ways to get the exercise you need in order to be healthy—and almost anyone can do it. Walking can strengthen bones, tune up the cardiovascular system, and clear a cluttered mind. This uncomplicated but important activity continues to attract researchers, reports the March 2011 issue of the Harvard Health Letter. Areas of recent research include:

• Walking speed and health. Later in life, walking becomes as much an indicator of health as a promoter of it. After age 65, how fast you walk may predict how long you have to live. Walking, or gait, has long been recognized as a proxy for overall health and has been measured in many studies. Researchers have found a remarkably consistent association between faster walking speed and longer life.
• Benefits of hiking poles. Using hiking poles can increase the cardiovascular workload of a walk because you work your arms as well as your legs. Hiking poles help keep a hiker more upright while walking and help with stability. Using poles is also associated with a reduced risk of ankle fracture. One study found that people who used poles reported less muscle soreness and recovered faster than those without poles.
• Finding the right walking shoes. Pain from arthritic knees makes walking difficult. Shoes with thick, cushiony soles are believed to help. But some recent research is challenging that belief with results suggesting that thinner, more flexible soles actually put less load on the knees. Walking in thinner walking shoes or flip flops, which were both equivalent to walking barefoot, produced less knee adduction (essentially pressure on the knee joint) than did walking in clogs or stability shoes.

Read the full-length article: "Talking of walking in three easy pieces"