Endurance workouts and heart rate

Because I’m training for an ultra event, I really want to include a longer Z2 session during the week (doing a long ride at weekends anyway). I just did 90’ and I set the intensity to 60% FTP because 55% FTP just seemed too low. Everything still nice and easy. But my heart rate sat in Z1 the whole time, and I’m thinking that might be too low? So do I use watts or HR as my target? I watched this video by Seiler on “How low is too low?” but I couldn’t really work out what his conclusions are. He seemed to use HR decoupling as a measure of “too long”, but I’m at a loss about “too low”. Does anyone understand it better than me?

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You’re not alone, I’ve watched that video a couple of times and still have no idea of the answer. 65-75% of ftp works for me, long rides closer to the bottom of the range, shorter rides a bit higher. For hr I like to average a bit below 70% of max and try not to go over 75%. I guess everyone needs to find out what works for them personally.

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That’s helpful! Thanks.

Just read this this morning.

Off Season – Base Periods

  • Main focus on HR, observe power, working with as much power as you can while maintaining the heart rate range.

Great! Thanks.

This is also interesting since I just posted separately about how the AI set my FTP too high. So I’m not challenged enough by lower power zones, but I’m finding threshold and VO2 max set too high. Maybe another example that FTP doesn’t capture the full range of training adaptations.