Hip joint restrictions can lead to back pain, leg and knee pain as well as neck pain. It can also lead to injury due in part to improper body mechanics during workouts attributed to limited range of motion.
Whether you cycle, run, play squash or lift weights, the benefits of massage and stretching should not be underestimated. If you have restriction in the hip joint you are working against yourself, your movements are playing tug-of-war. With tightness in the back of the hip you have to pull harder with your hip flexors and your abs to bring your leg forward. Restrictions in the front of the hip leads to back tension and too much external rotation on your kick back. It can also cause knee pain due to the pressure pushing the quad over the knee during squats and lunges because the hip joint is not dropping down and back as it should.
Keeping your hip joints unrestricted will help you perform better and keep you from getting fatigued as quickly.