You have two choices: 1) Be luck enough in middle school, junior high or high school to be taught basic body movements and step-by-step instructions in the Olympic lifts, powerlifting, mobility, flexibility, kettlebell training & tumbling 2) Apply Intervention For most of us, it's option two. Five Principles: Here are the answers, but the questions are the real keys-- 1) Strength training for lean body mass and joint mobility work trump everything else. 2) Fundamental human movements are. fundamental. 3) Standards and gaps must be constantly assessed. 4) The notion of 'park bench' and 'bus bench' workouts must be applied throughout the training lifetime. 5) Constantly strive for mastery and grace.