When you think of the most difficult part of hiking, most of us think of the uphill as the most strenuous and physically demanding. But what about the downhill? We should not ignore the descent - or even the stairs down - as an exercise strategy. True, you don't get nearly as much cardiovascular benefit from the downhill, but the muscular benefit is great, especially since we don't use the muscles responsible for this motion as often.
Here is a bit of the Kinesiology behind hiking. Hiking uphill (or up stairs) involves the use concentric movement, or muscle shortening exercises. Flex your bicep or upper arm and you will see what I mean. Think of these muscles as those that help you accelerate, so anything that helps you move from point A to Point B. The quadriceps in your thighs are such muscles. Hiking downhill is eccentric, or muscle lengthening. This action results in your muscles working against the pull of gravity. Your muscles are helping you decelerate instead of accelerate, thus your body is already in motion and your muscles are trying to slow you down or stop you. This deceleration is why hiking downhill can be so strenuous for our muscles and why we tend to feel pains never felt before - i.e in the hamstrings and the muscles around your knees and hips. We don't use these muscles as often, so we need to be sure they are ready for your descent. Aside from the muscular benefits of downhill movement, a study conducted by the American Heart Association presented in November 2004 found that both uphill and downhill had distinct effects on blood sugar and blood fats. Both downhill and uphill walking reduced LDL (Low Density Lipids or bad) cholesterol by about 10%. Only uphill hiking reduced triglyceride levels (triglycerides are responsible for heart risk factors), while downhill hiking was much more effective in removing blood sugars and improving glucose tolerance. This is great information for everyone since metabolizing sugars is important, but especially for diabetics or those who are borderline.
It is important to prepare yourself for those downhill hikes. See my previous blog "My Knees Never Hurt Before" for tips on protecting your knees while hiking downhill. Also, here are a couple not-so-typical exercises to help you condition you for the hike down. Step Downs - see the included YouTube video; Side Step Downs - Same exercise as the Step Downs but off instead of stepping off the step forwards, step off from the side, or laterally. Curtsy Lunge - http://www.youtube.com/watch?v=SOLzLKwXmP4 (Great for Hips) For those standard exercises such as lunges and squats, try going slower through each repetition. For example, for each squat, count to 5 on the way down and 5 on the way up. This will make your muscles work against gravity instead of working with momentum.