Well I never - after putting it off yesterday (my excuse was that it was too hot....) I finally got out there this afternoon, and cleverly managed a run which was pretty much flat (unusual for me as I invariably end up struggling up a big hill panting like an asthmatic serial killer!) And it wasn't nearly as difficult as I thought it would be, so anyone wondering whether they can make it - YES you can!
Only problem is I don't have time now to change for the school run so will have to show up in the playground in all my fluorescent pink sweaty magnificence! Happy days!