After warming-up do 4 x 90 seconds at race effort (3.5-minute recoveries). Cool down very easily and stretch
WU: Warm up for 10'
MS: After wu, do 4x20" fast (5k pace) with a full recovery between each.
Continuous open water swim. Try to think about keeping good form like you're in a pool. Little head movement, good body roll, long follow through, high elbow recovery, etc… Practice sighting too - pick a point and try to get to it sighting as little as possible.