Extreme endurance training poses several potential risks, including injury, overtraining, and adverse cardiovascular effects. Individuals may experience muscle damage or joint issues due to repetitive strain from prolonged exertion. Overtraining can lead to fatigue, decreased performance, and mental burnout, significantly impacting motivation and overall well-being. Additionally, extreme exercise may increase the risk of cardiac events, particularly for those with pre-existing health conditions. It's crucial for athletes engaged in rigorous training to prioritize recovery, nutrition, and listen to their bodies' signals to mitigate these risks and ensure sustainable practices over time.