When your muscles are sore, it means they're getting stronger. What it really means is that you've damaged and torn the microscopic-sized connective tissue that surrounds your muscle fiber. There is evidence that this soreness may be due to damage to the muscle fibers themselves. Lowering a heavy weight to the ground, or using your leg muscle to break your progress during a hike or a game of basketball or tennis. If you plan to participate in an activity that requires eccentric contractions, build up slowly over a period of several weeks, to give your muscles and connective tissue time to adjust.
Heavy people have a harder time burning calories when they're exercising.
In fact, the more you weigh, the more calories per minute you're guaranteed to burn when you're doing weight bearing exercises. People who are out of shape sweat more than really fit people. One of the natural changes that occurs as you begin a new exercise program is that your perspiration rate goes up. That's because you're producing heat as you exercise. When your body temperature rises, small blood vessels in your skin widen and draw heated blood to the surface.