You’ve probably heard the phrase, “Exercise is the best medicine” — and for good reason. Regular movement improves sleep, boosts energy and supports mood while also strengthening the heart and lowering stress. It’s one of the most powerful tools for preventing, and even detecting, cardiovascular disease early, as symptoms such as shortness of breath often show up during activity before they’re noticeable at rest. Research shows that consistent, moderate-intensity exercise is more beneficial than infrequent bursts of high-intensity activity. That’s why I have devised simple 20-minute workout routines for every decade of life — short enough to fit into your day but designed to be done regularly to support long-term heart health. Most health organizations recommend at least 150 minutes of moderate-intensity aerobic activity per week, so think of these regimens as a strong, efficient base to build on.…