Intention: This session will push your medley endurance without swimming too much butterfly :)
Advanced
Warm up: 200 Swim / 200 Kick / 200 IM / 200 Pull / 200 Swim
2 x
[4 x (25 Butterfly / 50 Backstroke / 75 Breaststroke / 100 Freestyle) Descend 1-4 - 20sec rest]