A vision in yellow

Some locations in the London Borough of Hackney.
Some locations in the London Borough of Hackney. (Photo credit: Wikipedia)

Yesterday I ran in the Hackney Half Marathon – my first ever race at that distance. It was a very hot day and I ran a poor race – I had aimed to keep a 5’30” pace per kilometre but in fact ran the first 7km faster than that and ran the first 10km three seconds faster than the 10km I ran last month: not very clever.

I ended up paying the price – going into meltdown at about 11 miles, though I did finish and that’s something to be proud of.

But it is fair to say I was in something of a state by the time I crossed the line, in 2:15:45 (my hope had been for something around 1:55).

Desperate for some sort of energy restoring drink (I missed the energy drink handout on the way round, possibly because by that point – at 8 miles – I was already approaching zombie runner state) I flopped to the ground and drank the “energy” drink I’d been given (actually I think it had little calorific value and the energy it claimed verged on new age mysticism).

Only feeling slightly better I decided to head off to the bag collection point, knowing I had two genuinely sugary Lucozade bottles in my bag.

As I stood up I seemed to get cramp in every muscle in both legs and then – strangely – my vision was washed a sort of sepia yellow.

I didn’t feel faint – particularly (though it’s fair to say I wasn’t fully compos mentis either) – but I did think, “oh here we go”. But the moment passed quite quickly – especially as I knew I had to complete standing up to end the pain in the legs – and I staggered off.

Since then I have read that this is quite likely to be caused by low blood pressure – or, less likelier, by hypoglycaemia. Low blood pressure might seem an odd cause in that I’d just undertaken some extremely strenuous exercise – but I dare say blood pressure in my brain was quite low, with blood diverted to my limbs, and suddenly lowered further by the effort of standing.

It was a stark reminder, though, of the way that our vision of the world is completely internally created. “Colours” are purely perceptional, not real.