Either you were dehydrated or over-hydrated and needing electrolytes that the excess water flushed out of your body. Seems I need extra potassium after many rides so I always consume something with plenty of it, like dates, yogurt, V8, or Mortons Lite salt on a salad or veggies.
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The Lord is merciful and gracious, slow to anger and abounding in steadfast love. - Psalm 103:8
I am a cyclist. I am not the fastest or the fittest. But I will get to where I'm going with a smile on my face.