One workouts that is a staple of mine is 6 x 250m with 90 seconds rest. While at first it looks simple, the velocities and timing of it is far more complex than I thought ten years ago. Some younger and slower athletes find it to be a heavy conditioning workout for the 400m, some advanced and fit athletes find it speed endurance, and the elite find it a way to maintain the body at specific cycles without breaking down the body. Why 250m and why 90 seconds? The simple reason is that the 90 seconds rest is a walk to the starting line protocol and it takes 150m in length time. Most coaches use walking distances since track doesn’t use pace clocks as much as swimming. This summer I will be using my new lactate tester with the help of a golf cart to get some sampling of athletes for curiosity sake. I have seen readings above 20 mmol/L but it doesn’t mean as much as the median and mean with deviation of the sprint times. I like 85-90% speed with HS kids at 80-85%.
Note/Edit: The 250m time is based on October time trials, speed and conditioning will slide someone’s abilities but they should never be based on calculations from PRs. The percentage is based on effort in practice. Each time must be stable enough to hold all 6 at lower levels but I have done 4 at faster speeds. I will let other coaches comment on some amazing workouts in Toronto. My belief is finding a threshold that one can repeat all 6 reps at and the goal is to keep the average as low as possible.