The best fitness gifts for your friends who work out

Fitness fanatics can be pretty intense. You'll probably identify us from miles away, decked out in workout gear, obsessing over the food we eat, or discussing our gains nonstop. A fitness lover has probably invested a lot of time and money into tools that can help improve performance, which can make us tough to shop for -- we probably already have everything we need! But we're also very likely to be super excited by any new toy that could boost our workouts. Plus, the most dedicated of us probab...