You can see the sessions I run for my sprinters here:
This is a rough cut and I can and do change them depending on weather (UK is highly variable on a daily basis). What you’ll see though is the max V work I do with the long sprinters is limited. This is for two reasons, first and foremost it’s what I’ve developed over time and I find I get far less injuries in my groups that way. (I am confident it works as I have two athletes who follow this in the top 10 in the UK for their age groups, one of which is a 15yo running 49.low for the 400m). Second reason I saw a talk with Clyde Hart and this convinced me of the benefits of tempo work. While I believe in the importance of speed reserve, I also believe that a 400m runner needs to be able to run long distances (200-300m) just under their maximum and thats where the sweet spot is.