The outdoor versions of a lot of the recovery or zone 2 ones (Pettit etc) are pretty easy to follow outside - it’s just warm up then X number of minutes in Zone 2 or endurance.
TR outside instructions for Pettit:
Warm Up:
- Ride for 5 minutes, gradually raising your power from 138 to 165.
Main Set:
- 51 minutes in between 165-192 watts.
Cooldown:
- 4 minutes easy.
So yeah that’s Ok to follow. Obviously you’ll likely hit some junctions etc in the 51 mins but it’s pretty easy to keep within the band while you’re moving, as they are quite wide. I much prefer doing these type of workouts outside in fact.