Ryan Woodruff, Lynchburg YMCA
We did this set in SCM. We wore fins for the first 16 and then took them off for the last 4. Swimmers were encouraged to push themselves on the underwater 25s, but could take a breath and go back under if needed.

Free Swimming Workouts, Sets, Ideas, and Dryland Exercises from Professional Coaches Around the World
Ryan Woodruff, Lynchburg YMCA
We did this set in SCM. We wore fins for the first 16 and then took them off for the last 4. Swimmers were encouraged to push themselves on the underwater 25s, but could take a breath and go back under if needed.