I'm in week four of personal training and have to hold my hands up: I'm a convert. In fact I've become a bit addicted. It's going to be hard to give this up after running my half marathon in October, so I might not.

 

The last couple of Sundays have involved going for 11am runs around Hyde Park. Now this is something I would never do if I didn't have Karen waiting there for me. But after a 10K jog or game of relay sprints on a beautiful sunny, Sunday morning you feel absolutely ruddy brilliant and alive.

 

Even the fella (who's not one to leap out of bed before 9am at the weekends) has been enthused. Though that may be partly owing to the fact he accidentally found himself running with several hundred women dressed in pink for last Sunday's Race for Life.

 

In between runs I've been at the gym with Karen building up muscle (I have none on my upper body), toning my legs (they need it) and doing some intensive exercise bursts to build the heart muscle (so I can live forever).

 

We've done boxercise, which made me feel like some kind of secret underground Fight Club member, and we're still working on those press-ups.

 

Readers of this blog may remember that when the training began, I couldn't even do one full-size, proper grown-up version of one. Now, as the Count von Count of Sesame Street might say, I have managed two, magnificent, press-ups!

 

My rugby-playing brother may snigger but he'll be laughing on the other side of his face when I get to ten - and show off my dangerous new boxercise skills.

 

I'm doing my personal training with Matt Roberts. To find out more visit mattroberts.co.uk.