This is a swim endurance set so keep early reps comfortable as finishing strongly is important.
If you cannot complete 3000 in 1hr do same sets but with 750m or extend time allowed.
The aim of this set is to push up aerobic capacity and improve %of vo2 max at which threshold occurs. This means working at 90%HR so expect to see it climb. It may not come down much on recoveries. It is important to keep your vV02 pace (2.34 for these reps).
We are running really fast so pick a well lit area.
A simple swim set completed at around threshold pace. The aim here is to build swim specific endurance.
10m @z2 rising to zone 3 4x 1 min spin up@high z3 1min Ri easy spin 5x4mins @z3-4 3min easy pedal Ri 5 min easy pedal w/down
The aim here is to build aerobic and muscular endurance whilst limiting ling term fatigue. The effort metric is given in RPE .because your heart rate may well remain high after the bike effort and be an unreliable indicator of effort. If you can talk and eat, then that is about the correct effort level.
A set to help improve pedal efficiency whilst building strength. However ,the effort levels should not lead to large amounts residual fatigue.
This should be an easy ride with the aim of developing aerobic endurance whilst limiting post exercise fatigue. You should be able to eat or talk all the way through the effort.