Hi Jo!
Here’s a generally agreed upon table of percent of FTP that you should target for the below distances:
| Race distance | % of FTP |
|---|---|
| Sprint | 90–105% |
| Olympic | 85–95% |
| Half-Ironman | 75–85% |
| Ironman | 65–80% |
A Sprint Distance Tri would have a 20km TT, and the Olympic Tri would fit your 40km TT well. For the 34km TT, you’ll want to target somewhere around 90-95% FTP.
I hope this helps!