Koch focus on 100m/200m in 1983 because injuries prevented her to go any further in the speed endurance development. She ran 7.08 at 60m indoors, and outdoors 10.83 for 100m, 21.82 for 200m and in relay 400m anchor leg 48.55. Her best flying 30m that year was 2.86.
1985 was the year she broke the 400m WR to 47.60, she improved indoors to 7.04 (WIR), then outdoors she ran 10.97 (w-0.3) in August in a rare attempt. At 200m, Charlie mentions 21.56 time trial before the World Cup which is in accordance with 21.78 in August (wind -1.3), also 21.90 in October in lane 1 (w-0.7) at World Cup 2 days before the 400m WR. Her flying 30m was 2.86 which equaled her lifetime best when she was focusing on short sprints in 1983, so her speed in 1985 was at her highest level the year she set her last 400m WR.
By the way, Koch had one of the lowest blood lactate level after competition races from 60m to 400m among the GDR crew.
What’s your take on that?