environmentalist. 1  a person who accepts the theory that environment is of overriding importance in determining individual characteristics. 2  a person working to solve environmental problems, as air and water pollution, the exhaustion of natural resources, and uncontrolled population growth.
1 Muscle helps you with aerobic exercise. The stronger you are, the better you will be at any aerobic activity.  Weight training improves your body's muscle-to-fat ratio (you end up with less body fat and more muscle), which improves both your health and your fitness level.
Whether you need to lose 10 or 100 pounds, adding aerobic exercise will burn calories, improve your circulation, increase your lung capacity and improve your mood. While a gym membership is always an option, the Mayo Clinic recommends walking as a gentler method of losing weight and improving your health.