A close call

It was a fine day, and we happily cycle thought Bedok Reservoir.
It all go well till my legs so haywire. My friend and I race through 1Km to and forth when
we go in reverse of the path, within 670m, I nearly lost control of my legs.
Then dizziness takes over me and I had to force myself to stop.
It's then I signal to my friend to stop the race and force myself to go the nearest resting bench.
Even so it's difficult to move myself there as I had a chance to collapse when I take every step there.

My vision turn purple, hearing turn very dull and muffed.
My head felt so light that it's impossible to know if I actually have a head.

Now in recovery position, it takes about a full 15 minutes to get back on our way.

Now this is a real close call as even though I know what I'm doing, this calls for action whenever we do "full" sport.

Now I can do normal activity, hope this don't happen later or again in future.