aerobic sets which makes sprinters puny and weak

Phil core strength, which many people equate to ab work, can't hurt either your sprinting or middle distance, but it can help both. Fly is very dependent on back muscles - the "opposites" to your abs - so I would include back and lat muscle weight work outs, too. If you could add 10 minutes per day for core strength, it may be a simple as a couple typical ab crunch/transverse ab sets and some "flys" and lat pulls with handweights. Maybe, if you were to dedicate 4 days per week to core work, on opposite days you could focus on abs/transverse abs and back/lateral (side) muscles. I have been amazed at what a minimal amount of REGULAR core work has done to my swimming, running, and soccer skills...

Phil core strength, which many people equate to ab work, can't hurt either your sprinting or middle distance, but it can help both. Fly is very dependent on back muscles - the "opposites" to your abs - so I would include back and lat muscle weight work outs, too. If you could add 10 minutes per day for core strength, it may be a simple as a couple typical ab crunch/transverse ab sets and some "flys" and lat pulls with handweights. Maybe, if you were to dedicate 4 days per week to core work, on opposite days you could focus on abs/transverse abs and back/lateral (side) muscles. I have been amazed at what a minimal amount of REGULAR core work has done to my swimming, running, and soccer skills...