In less than four weeks' time - April 22nd - I'm running the London Marathon. It's a pretty famous distance of 26 miles 385 yards, but if you've never envisaged how far this actually is, it's like running from Tadley to Maidenhead. Or from Bristol to Bath - and back.

My target time was three hours, but my right knee has taken exception to running 50 training miles a week and is giving me no end of grief, so whether three hours is still doable is anyone's guess. If you were wondering how quick you have to run to complete in under three hours, set the treadmill speed to 14.5 next time you're at the gym. It's bloody hard work to run at that speed for a couple of hours let me tell you!!

More important is finishing in under 3:13, the time my dad did when he was 40 years old. I will take a battering if I finish slower than that being 17 years younger than he was when he set that time.

But perhaps the biggest challenge I'm facing is the team I'm running in (Team PB) have just sent me a nice little vest to run in. So as well as all the miles I'm having to run to train for the race, I've now got to work on my feeble upper body to look good on the mean streets of London.

For those of you who enjoyed the mankini skydive, that fundraising was all part of this larger project. I've moved everyone's generous donations from that page onto here, so we start at £823 of my target of £2500.

All the money raised gets split 50:50 between Breast Cancer Care and The Prostrate Cancer Charity, the two most common cancers in the UK.  Five years ago my Nanny B (Beryl to many) died from cancer that started in her breast. It took a year for the cancer to finally wear her down and finish her off - I won't go into any more details as  the relatively common nature of the two diseases means that many of you will have shared similar experiences with your own loved ones. If you haven't - count yourself lucky.

I've got a pretty heavy target of £2500 to raise so every penny (or pound, or tenner ;) ) counts. If you donated to the skydive don't feel you have to again, but it would be grand if you did.