Whether you’re a weekend warrior or you get your exercise walking the dog, chances are that if you’re physically active, at some point you’ve been on the receiving end of an athletic injury. Believe me, there is nothing worse than to be hobbled by an injury just before your big tournament, an active vacation, or just as the weather turns warm enough to be able to play outside. I’m writing from experience here. I’ve blown out my knee on the altar of faulty ski equipment. I’ve suffered stress fractures from stubbornly refusing to stop running. And I’ve nursed a shoulder injury caused by not training adequately for a paddling event. Uh, make that not training at all. The good news is that you can do a lot to make sure you end up on the field rather than on the sidelines. Here are my best tips: Warm up. This means …