Final answer:
Running on a track is preferable for track practice as it simulates the actual performance environment better than a treadmill, offering a more specific training stimulus that includes factors such as air resistance and surface variations.
Step-by-step explanation:
For specificity training, which refers to training in a manner that closely simulates the actual performance environment, running on a track is preferable for track practice. When running on a treadmill, the movement and mechanics can differ from those on a track. For instance, air resistance and variations in surface are not experienced in the same way on a treadmill. Therefore, running on a track provides a more specific and relevant training stimulus for track athletes, helping to replicate the conditions faced during actual competitions and improving the transfer of training to actual performance.
However, treadmills can be used for certain types of training, like interval workouts or when weather conditions are poor and prevent outdoor running. It's also useful for controlled pacing and can be a beneficial supplementary training tool. But when it comes to optimizing performance for track events, specificity training on an actual track is critical.