Our Set of the Week will help you work on IM transition turns and on transitioning quickly from one stroke rhythm to another.
Swim four rounds of the following, with no extra rest between rounds. (Beginning swimmers could do two rounds; intermediate swimmers could do three rounds.) Wear fins on the final round. Keep track of your times on the 100 IMs and the 100 Freestyles, and descend time on these swims throughout the set.
Choose a sendoff that gives you approximately 10 seconds rest on the 25s, 13 to 15 seconds rest on the 50s, 20 to 25 seconds rest on the 75s, and 30 to 35 seconds rest on the 100s. To make things easy, you could use a 30-second base per 25 on your sendoff (or a 35-second base or 40-second base).