The biggest issue most people face in terms of the appearance of their arms isn’t a lack of muscle definition, it’s excess fat, meaning that what you’re eating is as crucial for fixing the problem as the amount you’re exercising. Instead of grabbing an electrolyte drink after your workout, try adding some grapefruit juice to your routine; researchers at Vanderbilt University found that obese study subjects who sipped a half-cup serving of grapefruit juice before meals significantly reduced their weight and BMI when compared to those who drank water instead. Fortunately, when you lose fat, it disappears all over your body, so a few sips of real grapefruit juice —the fresh, no sugar added stuff— can help you ditch those batwings for good.
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.