I'm naturally athletic. I've been involved in sports since I could walk. So, for me to be sedentary is just unacceptable. Not only is it great for your physical body, but it gives me more energy during the day if I've worked out. I feel better. I look better.

Human bodies are designed for regular physical activity. The sedentary nature of much of modern life probably plays a significant role in the epidemic incidence of depression today. Many studies show that depressed patients who stick to a regimen of aerobic exercise improve as much as those treated with medication.

Like our physical bodies, our memory becomes out of shape. As children, we are constantly learning new experiences, but by the time we reach our 20s, we start to lead a more sedentary life both mentally and physically. Our lives become routine, and we stop challenging our brains, and our memory starts to suffer.

If a brain is exercised properly, anyone can grow intelligence, at any age, and potentially by a lot. Or you can just let your brain idle - and watch it slowly, inexorably, go to seed like a sedentary body.

Poor diet and sedentary behaviour have led to an increase in obesity and lifestyle-related disease and a huge rise in chronic medical conditions.