Take up rowing or kayaking. Doing a sport that activates your arm muscles will help you to tone your arm muscles. Consider taking up an arm focused hobby like rowing or kayaking, which requires arm strength and good core engagement. You can start by doing the rowing machine at the gym and then work up to taking classes in rowing or kayaking. You can also join a recreational rowing team in your area to get better at rowing and be more active on a weekly basis.
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.