People often ask me if I think I am putting my body (and life) at risk by doing this challenge and some of my training trips. I normally say 'no, not really', although to be fair, I have had a few scratches and scrapes over the last year or so. That said, I reckon I am doing pretty well, it's primarily my feet that have had a pounding.

Here's the main problems I have had to date:

1) Stress fracture of left leg: As a result of 'training' for my first marathon in 2009, I developed severe pain in both legs, although primarily my left. MRI scan revealed what was 'probably' a stress fracture. The furthest I had run in training was 11 miles. I have since learned to run 'properly', with faster cadence, landing on my forefoot and generally being a little hardier. Since then... no pain!

2) Blisters of every description: I have had some great ones over the last year, some literally the size of my whole foot. However, I hardly ever get them now, no matter how far I run. My feet seem to be a little more durable, although it still feels like I am running on glass over 75km.

3) Losing toe nails: I have lost 4 to date, although all have grown back! This often isn't that pleasant. I had to cut off the big toe nail on my right foot with some kids scissors I found in my flat.

4) Knee issues:  Both knees sound like they have gravel in them... I am reliably informed this is nothing to worry about. I also insist this is NOT from the training, rather the training has improved this significantly

5) Bleeding nipples: I never thought I would struggle with this, but run for long enough, and your T-shirt will basically rub your nipples off over time

6) Blistered chest: Heart rate monitors on long runs don't seem to work to well for me. I have what could well end up being a scar where mine has rubbed and left very sore blisters.

On the whole, I strongly support the view that the body can endure far more than most people think is possible and that exercise, even 'extreme' exercise is fundamentally good for you if you build up to it and have some semblance of an idea of what you are doing (FYI - I am still very much learning!).