Femke's overall 400 PB is 49.17i from 2024.Modelling suggests a strength based 49.17 400 athlete would run:
200 in 22.86 (Femke's PB is 22.64i from 2024*)
500 in 66.47 (Femke's PB is 65.63i from 2024)
600 in 1:23.65
800 in 2:00.34
*40 minutes after a 49.96 400.
In 2024, Femke was both faster (200) and fitter (500) than her 400 PB suggests, which means she could definitely run faster than 49.17.
So Femke's speed reserve is at least 22.64. Let's take 1% off that 200i PB to account for the fatigue she carried into that race from the 400, 40 minutes earlier.
22.64 x 0.99 = 22.41
Modelling suggests a strength based 400 athlete with a 22.41 PB would run, just off 400 training:
400 in 48.69
500 in 65.81 (recall Femke's PB is 65.63i from 2024)
600 in 1:22.83
800 in 1:59.16
So, even before adding in extra aerobic work, Femke was very likely in the above shape in 2024, and if the winter has been a success, expect next month's 800 and the 600 to be under these times.