I was recently contacted by a current high school senior who is stuck at 51 in the 400m. His goal for this season is to break 50.00! He wrote me asking for a few tips. I have three suggestions for you if you want to PR in the 400m or break 50!
TIP ONE - Run hills. Hill training in the early season will significantly increase your finishing speed/strength over the last 100m of the race. Several years ago, the University of Minnesota had two different men run 44. They were both local Minnesota HS runners with modest HS pr's. I was so intrigued by their development that I collected all of their training information from their coach. They did hill workouts twice a week in the early season and continued them deep into the outdoor season. One of my favorite hill workouts is to run 6- 8 x 150m-250m hills with a walk down recovery.. Take 5 minutes or so to recover and then find a 500m hill to sprint up with all you have left.
TIP TWO - Incorporate Aerobic Strength work into your training. There are many ways to achieve this goal without having to become a cross country runner. A few of my favorite aerobic strength workouts include 3 x 5 minute runs at a quick tempo with 3 minutes rest, 10-12 x 100m in 14-15 with 45 seconds rest and multiple sets of diagonals on the track. For more information on how to run diagonals see here: http://www.sweatelite.co/david-rudisha-key-workouts-diagonals/ - I would suggest working up to 6 sets of 3 diagonals with a 3 minute rest in between sets.
TIP THREE - Run split intervals with short recovery to prepare your body for the late stages of the race. My favorite specific prep workouts are 2 sets of 2 x 200m at goal race pace with 30 - 45 seconds recovery (you should take 10-15 minutes before starting your second set) and 2 x 300m - 200m with 45 seconds rest. Run the 300m controlled, but fast enough to get you tired (aorund 45 seconds for a 50-second 400m runner) and then run your 200m as fast as you are able.
For more 400m training suggestions see here- https://www.fasttrackrecruiting.com/athletic-recruiting-blog/2017/11/27/college-track-and-field-training-train-like-a-top-level-ncaa-200m-400m-runner
To see the effectiveness of this training methodology see here - https://www.fasttrackrecruiting.com/athletes-i-have-coached/