Long hours of biking can lead to muscle stiffness, especially in the neck, shoulders, and legs. This stiffness can reduce your strength and make it difficult to lift even small weights. The sciatic nerve, running from the spine to the legs, can also be affected by prolonged sitting, leading to pain and discomfort. Biking often keeps the knees and shoulders in a fixed position for extended periods, which can result in joint pain and muscle weakness. This can affect your ability to walk and even lift small objects. The constant stress of riding without adequate rest can impact mental health, potentially affecting heart function and respiration, leading to lung problems.