Run 90' on a flat course or treadmill. Keep HR in Zone 1-2. Think about form and running with relaxed arms, face, neck, shoulders, and hands. Stretch when done and add in Core 1, 2 or 3.
Swim Endurance - KEY WORKOUT
WU: 400 warm up free, each 4th lap is backstroke.
5 x 200 with 30 seconds rest between each.
Kick 200/kickboard, 100 kick on back, 200 easy free.
Repeat main set, with last 200 as cool down.