Here is a workout I did with my boys high school team at Arroyo Grande:
25×25 @ :35 @100 free race pace
300 easy recovery
20×50 at 200 free race pace @:50 or 25×25 at 100 race pace @:35, non free
3×100 ascending swim @1:30
20×25 @50 RP @:35, odds off the blocks
