Walking is definitely one of the best exercises we can do.

There are few other activities which are so inexpensive and environmentally friendly as a good walk. Walking is an exercise which increases independence, without the gym or expensive equipment. It is green transportation without harmful emissions. Walking is psychotherapy, meditation, mental stimulation, a natural-high, a short inexpensive vacation and a relaxing retreat. It is accessible to almost all age, social and economic groups.

But most of all, walking is extremely healthy for virtually every part of your body - true magic, a transformer of body and mind. But it can be painful on the knees for those who are overweight or for those with arthritis.

Walking programs are often prescribed for inactive or overweight people. It is usually recommended that people walk at a brisk pace.

But a 2007 study published in the journal Medicine and Science in Sports Exercise has shown that walking at faster speeds causes more force through the knees in obese people, and this may aggravate knee conditions such as arthritis. But there is a solution to this problem.

The study used a treadmill which also serves as a force platform to find the effects of walking at different speeds on normal-weighted and obese people. The forces on the leg were 60 per cent greater in obese people (those with a BMI of 30 to 43) compared to normal-weighted individuals at the top speed of 6.5 km/h.

Normal weight subjects preferred to walk at a speed of 5 km/h. When the obese subjects in the study tried to keep up at the faster pace, forces on the knees climbed fairly dramatically. Not only that, but proper biomechanics started to fail at higher speeds causing an imbalance of force on the cartilage and increasing the risk for inner knee pain.

But if the obese subjects reduced their walking speed from 5 km/h to 3.8 km/h, the overall force on the knees decreased by 45 per cent, and it also rectified the force imbalances inside the knee.

With this slower walking speed, obese individuals have the same forces in the knee as normal weight individuals walking at a higher speed.

Another over-looked factor is that “brisk” for one is not “brisk” for all. In other words, overweight people don’t have to walk as fast as lighter people to attain the same heart-rate and workload. That is because at a given speed of walking and all else being equal, a heavier person’s muscles have to work harder to move their body weight compared to a lighter person.

So the lesson here is that by going a little slower you can still burn many calories and get healthier without causing pain or damage to your knees. Just make sure you go at a comfortable pace so that you are getting enough exercise but not so fast that your knees hurt. Vast numbers of people have completed successful weight loss programs entirely through proper diet and walking only. You don’t necessarily have to walk at 3.8 km/h. You can use a treadmill to measure the speed that is comfortable for you to walk, but ultimately the pace you go should feel right for you.

If walking is still very difficult even at slow speeds, then you could try activities that effectively decrease body weight like stationary bike or walking in the water.

Your ultimate goal should be to establish an enjoyable active routine, lubricate your joints while increasing strength in the muscles around the knees so that you can build up to a more brisk walk in the future.

When walking, take it easy, but take it.

Kerry Senchyna holds a bachelor of science degree in kinesiology and is owner of West Coast Kinesiology in Maple Ridge (westcoastkinesiology.com).