In reply to bruxist:
Yeah I knew I shouldn't I just needed it reaffirming! Thanks for the link, it's an interesting read.
I've felt much better today, but will leave it sometime before heading out with my trainers on. And then ease back in.
Wbo2- I think it's probably more to do with working in a school and every bug under the sun coming through our doors. My illnesses coincide with the waves of illness seen in the rest of the staff. I think I probably just need to be a bit more aware, keep all my windows open and sanitise the crap out of everything. Combined with managing the stresses of the job in a more conducive way, unfortunately having taken on a new role this year, it's unlikely that the stresses will reduce (despite teaching less!). Turns out dealing with the parents is much worse than dealing with the kids!
With regards the ultras, I agree, but the alternative is probably road marathons (I'd like a punt at a masters vest in the next few years) and I'm not sure that's less stressful on the body! I know I could go short but it doesnt really interest me!