Hard start vo2 max

Does anybody have experience with doing hard start vo2 max intervals and then using heart rate as a guide?

E.g. 2 minutes @ 115% FTP followed by 6-8 minutes @ 90% max HR?


And this:

Thanks both! My searching skills are in need of a boost…

Good articles here - follow a few of the links in his posts to get the updates…

Long story short - HR is not a good proxy for VO2. Use RPE 9/10 :wink: