Kettlebells are having a moment. These cannonball-like weights with handy grab bars come from a traditional Russian sport called girevoy sport. Unlike the ubiquitous barbells you can find in any weight-training room, kettlebells help you build flexibility as well as muscle.
When it comes to staying in shape, good intentions only get you so far. And when you consider the hurdles standing in the way of your workout – cold and rainy weather, the gym's location across town, lurking gym-goers, unwashed equipment – it's