My sweat sensor watched me lose my heat fitness, and start to earn it back
Nine cold days walking across Lapland undid a summer of heat adaptation, and my sweat sodium doubled. Here is that number going down, up, and back down again.
Earlier
What a Summer of Sweat Taught Me About Racing in the Heat
I spent a season racing in the mountains with a sensor reading my sweat, live — drop by drop. Here's what it showed me about my own body.