Pounding the pavement does a number on your legs. You can feel it. After a while, shin splits, stress fractures, and sore knees might hinder your gait. But before you get hurt and resort only to cross training, consider adding trail workouts to your endurance routine. Running on varied terrain keeps you on your toes, demands better forward form, and works opposite muscle groups in your legs and core. Plus, explosive heart rate intervals on a low-impact surface ensure max cardio benefits with low risk of injury.
But finding good trails—like running shoes— can be tough. Our advice? It’s all about taste. Figure out exactly what you want from your run. Maybe you like technical single-track littered with boulders and stumps to improve agility, or maybe it’s earthy double-track wide enough where you can cruise for miles. Maybe you like hot deserts, cool forests, or high-altitude mountain ridges. Being choosey isn’t a bad thing. It just means you’ll enjoy your run even more. Here, we picked America’s top 10 trails for serious runners who like challenge and variety.