The article on the Top 6 workouts to predict your 400m time has a lot of good feedback & alternative workouts on my Twitter account (again, please follow if you haven't done so). The responses are coming from proven, well known coaches like Kevin Tyler & Mike Hurst.
And finally, please join Richie Mercado, myself, and others at the 2022 edition of the NACACTFCA conference. Sadly, it's 100% virtual again. We will make it to Puerto Rico one day!