From memory his rule was add the number of reps to your season target time for the 200m to give the running time for that set. For example if your 200m target time for your 200m was 21s then you would perform the 5 x 200m in 26s I.e. 21 + 5 (no of reps in set) = set target time. The key to using a set like this depends heavily on your philosophy of training. Clyde placed extreme importance on this session and periodised it early in the week. It’s important to remember that something that starts of at 35s for 15 reps may look like and extensive tempo session but as it progresses down it will take the shape of intensive tempo and as a consequence have dramatically different impact on subsequent sessions around it.