After a bit of research, I settled on a Garmin Forerunner 405, with heart rate monitor. A bit pricey, but, if as I was starting to get serious about running/fitness again, I figured it was justifiable. Oh, ok, it's a bit of a boy's toy as well...!
It has proved to be a useful addition alongside the GetRunning app, in that I can see how far I've run each session and also how I've done with each jog/walk section of the individual days. On one of the week two runs, I was stupid and neither ate nor drunk before going out, plus left it till late morning on a particularly hot day to go running. I did struggle, but kept going, convinced that I had not done as well as the previous run for that week. As it turned out, the data showed that I had run further and that my average speed was slightly better; admittedly my heart rate was nigh on 100% for a large proportion of it, though. But it was interesting to see that how negative I felt in terms of my performance ie that that had been a crap session, was not borne out by the Garmin data.
The Garmin display can be set up to give a variety of information and I decided to concentrate on the heart side of things, rather than just time and distance. I read up an awful lot on target heart rates and the various ways of working out the maximum for one's age and the various zones, then adjusted my Garmin accordingly, with the screen showing percentage of maximum, absolute value and the time of the session (just so I could make sure that the lovely lady wasn't adding on a sly minute here and there!).
Since then, I've endeavoured to keep myself to around 75% of my maximum heart rate, by adjusting my pace as I go. Interestingly, I've found that I've actually travelled further in the sessions and that my average speed has slightly increased when I've been monitoring myself in this manner. Prior to adopting this approach, I could see from the data that I was clearly faster for the first half of the session, then dropped down over the second part. Using my target heart rate, I have been more consistent over the whole session. And less tired at the end too.
Where the sessions repeat over the week, it is also possible to do a direct comparison of the previous runs and it is inspiring to see distance increase, average speed increase, but no increase in peak and average heart rates - which can only mean that there's some slight improvement in fitness creeping in!
But it's not just about heart rates. The excellent GPS on the watch tracks your route with amazing accuracy, working out how much elevation you've been up and down on your run (not much for me, living in Norfolk!), distance and calories burnt off (never enough!). All the data can be uploaded to your pc/mac and also online - where, if you're feeling masochistic, you can make your results public for others to pore over and also check other people's run results.
Finally, having the Garmin on the wrist is a constant reminder of the "spies in the sky" and that the gizmo is recording everything that is happening. This has proven to be a great spur on the couple of occasions where I've been tempted to take a breather!
I appreciate that such equipment is not for everyone; that for some it's enough that they have made it through the session and that they don't feel the need to be interrogated by some bit of electronic wizardry. For me, I know that by dint of progressing through the various weeks, then clearly I am improving, but what the Garmin does is give me proof positive that that is indeed the case - thus far, anyhow!