Long Interval Workout

Choose ONE of the following sports

Swim 3-4 x 400m TT, recover 4:00-5:00
Bike 3-4 x 5k TT, recover 4:00-5:00
Run 3-4 x 800m TT, recover 4:00-5:00
Row 3-4 x 1k TT, recover 4:00-5:00