Using a stationary bike every day can indeed help build stamina. It's a great low-impact exercise that can strengthen your heart and lungs, improving your body's ability to use oxygen efficiently. Over time, this can increase your endurance and reduce fatigue during physical activities. However, remember to mix up your workouts and incorporate rest days to prevent over-exertion and potential injuries. Also, always consult with a fitness professional to ensure your routine is safe and effective.