I am starting this week renewed and refreshed, partly because I've had a good rest, and partly thanks to a scolding from reader Kevin Pickering. "You just sound really miserable", he writes. "What are you trying to prove?"

Hmm. Good question, Kevin. A few weeks ago I asked readers to tell me what they hoped to get out of the army fitness programme. There was a fantastically varied response: Sam Gibson is hoping to join the prestigious HAC regiment in the Territorial Army; Richard Williams is in training for the sailing season and may attempt a triathlon (if he is toned enough to brave the "skimpy gear"); Nicole Keenan aims to raise money for charity; Matt Foulkes wants to look good at summer festivals; and Peter Jensen simply wants to find the motivation to get started.

I, on the other hand, don't have a specific goal. As Kevin pointed out, "You've no intention of joining the army, so why don't you just follow a fitness regime that you enjoy, or practice a sport that you can do in a group with people you like?" I guess because I want to push myself - and now that I've started, I want to see the challenge through to the end. Plus, despite all appearances, I'm actually enjoying it! I just have to keep reminding myself of that fact (with a little help from Kevin).

Monday
Shooting practice and cycling.

Tuesday
I hit the gym for today's run. I opt for a hill programme again, and find the changing speeds and inclines distract me from the ticking of the clock. Twenty-five minutes go by in no time. Back home, I get cracking on the strength exercise, and I'm really pleased to still be improving: on the first set of sit-ups I break the 80 barrier for the first time. Four sets of each exercise are required for the first time - the pace is really hotting up in phase three of the training plan.

Wednesday
Rest day (other than cycling).

Thursday
I decide to categorise today as the easy cardio day, as my usual cycling and korfball is on the agenda.

Friday to Sunday
Break for Easter! I celebrate the end of Lent with generous helpings of meat, beer and chocolate.

Monday
Circuit training at home. This day has started to get tougher, with 3x15 repetitions of each exercise required. I'm still doing decline press-ups and super-slow sit-ups, and the last set of each is quite challenging. I feel great afterwards, though.

Tuesday
Interval training at the gym. I'm filled with trepidation because I really struggled with this last time, and today I've got to repeat the intervals seven times, rather than six. I make sure I don't exhaust myself on the warm-up. As I ease my way into the first ten minutes, two muscly men either side of me are pounding the treadmill, so it's quite satisfying to suddenly start motoring. I end the session red, sweaty and exhausted, but it feels like an improvement on last week.

A handful of readers have emailed to ask the difference between running 'fast' (as stipulated in weeks one to four) and running 'hard' (as stipulated from week five onwards). As far as I know, there is no difference - I try run at the fastest speed that I can maintain for all the sets, with the final set pushing me to my endurance limit. I recover at a speed that I could maintain comfortably for a considerable time - basically a fast jog. I expect there are other ways of approaching it, though. Let me know if you'd like further clarification from Major Colclough.

Easter has eaten up into some of week 11, so it's time to crack on ....

· Are you following the official army fitness programme? Email rachel.dixon@theguardian.com to share your experiences in next week's training diary