The skin also serves as a release point for heat. (See “Why Does My Face Turn Red When I Exercise?” for more on that.) When you exercise, your muscles generate a lot of heat, which you have to give up to the environment so your body temperature doesn’t get too high, Hackney says. The heat in the muscle transfers to the blood, which shuttles it to the skin; it can then escape into the atmosphere.
The benefits of exercise diminish within weeks after a person stops exercising. Heart strength, muscle strength, and the level of HDL cholesterol decrease, whereas blood pressure and body fat increase. Even former athletes who stop exercising do not retain measurable long-term benefits. However, people who were physically active in the past often can regain fitness faster.
Stand with your feet hip-distance apart and your arms at your sides. Squat until your thighs are parallel to the floor. Keeping your arms straight, bring them forward and up until your upper arms are in line with your ears (A). Return to standing, then lift your right knee to hip height as you sweep your arms down across your body until the back of your left hand is outside your right knee (B). Return to standing and repeat on the other side. That's one rep. Do three sets of 12 to 15 reps, resting for 30 seconds between sets.
Then, step your left foot directly behind you (about 2 feet) and bend both knees to lower into a reverse lunge, creating two 90-degree angles with your legs. In this positioning, your shoulders should be directly above your hips and your chest should be upright (not leaning forward or back). Your right shin should be perpendicular to the floor and your right knee should be stacked above your right ankle. Your butt and core should be engaged.
Stand with your feet placed shoulder width apart and arms extend straight to your sides, raised at shoulder height. Now, do 50 small circles with your hands by rotating them in the forward direction. Then switch to 50 small backward circles. The backward and forward arm movement tones all the muscles of the arms including the triceps, biceps, shoulders and back muscles as well.
Downward dog is another Sun Salutation pose that tones the arms. For this pose, your body will form a reverse V-shape with your heels pressed down or close to the floor and your hands flat on the floor. Ideally, your spine will follow a straight line toward the ground with your hips pressed back. You may need to bend your knees to keep your body in the reverse V-shape.