How long can humans sustain running without stopping?

The length of time a human can sustain running without stopping varies depending on factors such as fitness level, hydration, and nutrition. On average, a well-trained runner can sustain running for about 2-3 hours before needing to stop and rest. However, some elite athletes have been known to run for longer periods, such as in ultramarathons where they may run for 24 hours or more. It is important to listen to your body and take breaks as needed to prevent injury and exhaustion.