@drbullockderm: 🧂 Why do some runners look like this after a workout? What you’re seeing is usually just dried sodium and electrolytes from heavy sweating — not “toxins.” Some people are naturally “salty sweaters,” especially during long runs, heat, or high-intensity exercise. Interestingly, this same physiology is why sweat testing is used in cystic fibrosis — because CF affects how salt is reabsorbed in sweat glands. Important: this is common in healthy athletes and does NOT mean someone has cystic fibrosis. Human physiology is just more dramatic than people expect.