[yvonne]

The 400 is definitely a sprint; the athletes even use blocks.  I don't think the 800 is considered pure middle distance anymore. It's more of a hybrid. Runners in the 800 gun it the entire race. They don't pace themselves the way runners of longer races do. Often, 800 runners will also run either the 400 (those with more speed) or the 1600 (those with less speed, but potentially more endurance). I think the 800 is the hardest race in track and field.

[yvonne]

The 400 is definitely a sprint; the athletes even use blocks.  I don't think the 800 is considered pure middle distance anymore. It's more of a hybrid. Runners in the 800 gun it the entire race. They don't pace themselves the way runners of longer races do. Often, 800 runners will also run either the 400 (those with more speed) or the 1600 (those with less speed, but potentially more endurance). I think the 800 is the hardest race in track and field.