If your summer plans include an Ironman or Half IM, here’s a set that will help you pinpoint a sustainable pace for race day. It’s also a great training set for non triathletes.
The typical way to determine your anaerobic threshold is to do a timed swim of 30 to 60 minutes. From that, you calculate your average speed for 100 yards/meters, and that’s the pace you should be able to maintain on race day. Timed swims can be kinda boring, so here’s another way to get to the same data.
10 X 300, pick a sendoff that gives 20 seconds rest
Descend your time on 1-3, then hold your time steady on 4-10.
After the set, figure out your average pace per 100 yards/meters on the final seven swims.