Running Tip #6. Avoid boredom in one sport (e.g. running) by cross-training (e.g. cycling, swimming, strength training). Cross-training improves total body strength and flexibility. At easy/moderate intensity, it can also prevent injury by correcting muscle imbalances caused by running or other activities that you're not aware of.
Cycling is complementary to running by strengthening quads to reduce the risk of knee pain, the most common running injury. But my favorite cross-training activity is swimming, a full-body workout with zero-impact. Swimming builds the cardiorespiratory system by forcing your body into an oxygen-deprived state. To quote Drake, "Michael Phelps with the swim moves!"