Yes, it is important to keep your foot flat at the bottom of the pedal stroke. This helps ensure proper form and prevents injury. When cycling indoors, you should be mindful of keeping your feet in line with the pedals throughout each rotation. If your feet are not flat at the bottom of a pedal stroke, you may experience discomfort or even pain due to incorrect positioning. Additionally, having an improper foot position can reduce power output and efficiency while cycling indoors. To maximize performance and safety while using indoor cycling trainers, make sure that your feet remain flat on each pedal rotation for maximum benefit.