I've read about the importance of HR to tailor training and be safe. I'm getting into cycling and going to a gym. I'm 64, 240#, and prone to pushing hard. This is my first month cycling after 2 months getting ready to ride at the gym. My four rides this week were 33 (solo), 24 (solo), 45 (group), and 25 (group) - I am slow climbing. I have a cadence computer.

I am reading Cycling Past 50, which seems to be primarily interested in race training. I plan on doing some training to improve myself more quickly than what I've been doing so far, just going out for longer distances and putting some effort into improving the pace slightly. But I am doing this for enjoyment and health, not so I can race. A power meter might be useful, but it's too much for me, both psychologically and financially.

Now I need a heart monitor. After reading lots of reviews on Amazon.com, I expect to get a wristwatch style unit with a chest strap, probably from Polar or Timex. But what features are important to a cyclist? Originally I thought I might have a small card with my HR zones clipped to my handlebars, but as I read the features I wonder if I am failing to see the possibilities. So, which of these features (from the Timex web site) matter?

1. Average HR for workout and Max HR for workout - I think these seem pretty standard and I would guess they are not especially useful. Or are they?
2. % of Max Display - This would be good, right?
3. 5 training zones - I didn't realize the watches could do this - is this actually practical on a training ride?
4. Time in zone memory - Again, I didn't realize the watches could do this - is this actually practical on a training ride?
5. Calories - Useless, right?
6. lap memory - Useful
7. Recovery timer - What is this?
8. 5 Interval timers - I don't even know what this means.
9. Data recorder saves exercise sessions in memory and downloads to PC - Does this really matter if I am not going to be training for racing?