Mountain bikers frequently have lower back pain. Depending on the activities that you frequently do on your body could cause muscular imbalances and later lead to back pain. For mountain bikers and people who sit for a long period of time, tight hip flexors is one of the main reasons that they have lower back pain because this tends to pull you pelvis out of alignment cause pressure on your lower back. Yoga helps with lower back pain, it deals with a series of stretching which can loosening up the hips and spine.