In your guys experience, what’s been the best distance (optimal distance) in training, for improving specific endurance for the
100m?
200m?
400m?
If I would have to limit myself to one training distance (not ideal) I’d say on average:
100m for the 100m
200m for the 200m
300-350m for the 400m (cause doing more than 1 rep at 400m at >95% in one training session is impossible for most)
You dont think overdistance works well?
120-180 for 100m
250-300 for 200m
350-450 for 400m
Good question. My eyes are glued to the responses you get.
Over distance training involves the completion of sprint runs over 150-500% of the competition distance.
-Standing 120s and flying 150s for 100m.
-Standing 230s and flying 270s for 200m.
For 400m
- 10 x Flying 100m at 400m race pace rests 3min
- 4 x 200m at 400m pace rests 5min
- 2 x 300m at 400m race pace rest 15min
You wouldn’t do any work around 450-500 for a 400 runner?
I can’t really argue with that. But don’t you think running a 180 is almost a different race? For a non elite athlete, say 4-5x180m could seem like a conditioning run rather than speed endurance.
Or maybe I, for one, could use a lot of endurance training! 
I was speaking for myself. I really like the 180-150-120 15-20min rest for the 100m.
What about 150-120-100-80, more specific to the 100?
And thoughts on doing 250-300 vs. 200-250 for the 200?
80-100m don’t work for me.
Overdistance can surely work and would form part of my program but I interpreted the question as asking for ONE particular distance. In that case I choose the distance (and therefore speed) which is most specific to the event.
Not sure if it’s changed but the great Tony Wells used to advocate race distance + 20%