My husband used to run for a full hour on a treadmill at a gym. He got terrible pains in his leg, and the doc. diagnosed shin splints (tiny cracks in the leg bones) AND phlebitis. As my husband has ricketts from malnutrition, jogging or running for long periods is very dodgy for him. The doc. said that jogging/running a lot wears out the joints and jolts the spine. Walking is better. I walk in the beautiful countryside, and it's never boring. The wildlife you see is phenomenal, and the lovely views lift your spirits. Also, it's free.