I'm running this half marathon for a number of reasons: partly because I need a goal as motivation to do some exercise, and I am overweight; partly because I love London; and partly (ok, mostly) because my wife Katie was diagnosed with breast cancer in December 2011. So this is a chance to raise money for a cause that is extremely close to me.

Katie is well and cancer-free, but only because of the advances in research, surgery and treatment which charities like Breast Cancer Now have raised millions to fund and implement. And there is still much to do, particularly for younger women:

- more awareness: as the wonderfully-monikered Coppa Feel make clear, there is one obvious route to early detection, but still not enough women know how important this is; put simply, Katie may not be alive if she hadn't found her cancer as early as she did

- more research: it's been surprising (to me) the relative lack of research into the effects of drugs and treatment on pre-menopausal women with breast cancer; estimating prognosis is an exercise in uncertainty already, but it helps if you know that you are making the right choices

- more support: this is where charities like Breast Cancer Now come into their own with clear, practical advice, online and off-line support and more. Our breast cancer nurse Sue was utterly *phenomenal*, helping us navigate various parts of the NHS and providing clarity, continuity and humour when needed most. (By the way, everyone in the NHS has been nothing short of magnificent)

So all of that needs more money and if I (or rather all of the people supporting) can help with that in a small way, it's worth doing.

Katie is amazing: not only has she overcome major surgery, chemotherapy, and three different types of drug treatment, but also powered on with renewed energy in life. She's now running her own fashion business in (what little) spare time she has from being a full-time secondary school teacher and head of year...

If she can get through all of that with good humour, doggedness, resilience and determination for the last 5 years, then I hope I can do the same with this much smaller, much less significant personal challenge for about 2 hours. And help Breast Cancer Now help more women like Katie in future.

Please support if you can with whatever you can afford.