Hi shaun78, my day job is not particularly physical (pretty sedentary actually) but my night job, twice a week, involves a lot of upper body strength.

If you are worried about ‘managing’ a fastday on a workday then I’d recommend being kind to yourself to start with and perhaps picking 2 fairly light days until you are used to the calorie levels and get past any short-term side effects (some people get headaches etc. usually because they haven’t drunk enough water and some have withdrawall type symptoms if fasting has forced them to cut down on coffee/ carbonated drinks etc. that they’re used to having daily).

However, once you’re used to this lifestyle I promise you can do whatever the hell you want on a fastday and it’s no bother at all. I ALWAYS have at least 1 fastday of the week on a day when I do my dayjob and my night job. I also ALWAYS have at least 1 fastday a week where I do a class at the gym and/or an hour in the pool. In fact, because of the ‘Xmas effect’ this week I did 2 consecutive fastdays on Sunday & Monday by 6pm on Monday night I had had 500-600 calories in the previous 44 hour period (along with a 1 hour pilates session). At 6pm on Monday night, after a full day at work, I did my first ever Body Combat class at the gym and kept up with the rest of the class – no problem. After that I swam 2.25kilometres in 45 minutes and then went home for my 500 calories.

Wasn’t even hungry when I woke up on Tuesday and lasted until midday lunchtime – no problem.

I’ve been doing 5:2 since August 2012, so I’m an old hand but I think I’d have been equally capable of this a year ago and if I’d been a bit fitter maybe even the year before. Take your time and build up to it but an active job is no barrier.