Did you know that just one hour of walking can increase your life expectancy by two hours? Now they tell me. If it’s Friday, then it must be time for education Monday. This week’s topic at cardiac rehab was Exercise Principles. Not surprisingly, smoking is the No. 1 preventable risk factor for heart disease. Nearly every heart patient in my cardiac rehab class is a former long-term smoker. They all regret it. If you’ve quit smoking, bravo! Just one year after stopping, you have cut your risk for heart disease in half. And after being smoke-free for 15 years, your risk is similar to those who have never smoked before.…