After losing my garmin 510, I had to get the 520 eventually.

One of the new functions is that you get a summary of your time in different heart rate zones, and you get a screen that gives you a recommended recovery time.

I found that after a short but hard workout of 18 km cycling, where I spent basicly half the time in zone 5, and the other half in zone 4, it recommends me 60 ! hours of recovery ? I thought this seemed pretty excessive, and will go for a ride again soon, less than 20 hours after, but wonder if anybody else have tried this function, and how they evaluate it.

At the other end of the Spectrum, another day I spent 1 hour in zone 1 on the rollers, and got the message that I needed 2 hours recovery.