Run down

[OutAlongTheRiver]

Having hit what feels like a peak of running capacity in recent weeks/months, I suddenly find myself struck down by flu/illness and wary of doing anything at all.

Last Thursday track session represented my best ever speedwork - with a set of four lots of 4 x 400m (with descending intervals 50s,40s,30s the 400m jog between reps), run at 1:35s per 400m which is around 3:55 per km. I managed to keep at this pace or faster on every rep, with exception of last one when our pacer (60+ year old Peter!) went out harder and ran 1:30 for the last 400m, which was so daunting I slowed to 1:40 or so.

Friday was journey up north. I was exhausted Saturday so no parkrun - and felt only like 3k jauntette in the afternoon. Sunday was long journey back. I suppose I should have realised that the tiredness = illness and lo I was wiped out and off work Monday & Tuesday.

Only today, Weds, am I back to upright and idea of running any distance seems laughable.

So how to work out run recovery from this state? Risk of post viral fatigue can be significant? I've only stopped running before due to laziness/injury. Never due to illness. 

Any views/pointers welcome!