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.
Aerobic exercises benefit your heart, and include walking, jogging, swimming or biking. Strength and stretching exercises are best for overall stamina and flexibility. The simplest, positive change you can make to effectively improve your heart health is to start walking. It's enjoyable, free, easy, social and great exercise.