AJ Anderson 
Surfers lose more sodium and fluid than they realize — masked by salt spray, ocean mist, and intermittent effort. Here’s the science-backed hydration plan for every session type, from morning glass to competition heats.
Pre-exercise hydration loads fluid and electrolyte reserves 2-4 hours before activity, during-exercise hydration matches sweat rate to delay fatigue, and post-exercise hydration replaces losses at 125-150% of sweat weight to restore full balance.
Rock climbing has exploded in popularity since its Olympic debut at Tokyo 2020. An estimated 35 million people in the United States climb recreationally, whether that’s on colorful gym walls or crumbling desert sandstone. But despite the sport’s mainstream rise, climbing hydration remains one of the most overlooked performance variables in the community. Most climbers … Read more
OCR athletes lose 1,000–7,000+ mg of sodium per race while surrounded by water that doesn’t replace it. Here’s the science-backed four-window hydration plan for Spartan Race, Tough Mudder, and DEKA athletes.
Hydration needs vary dramatically by sport: endurance athletes need 400-800 mL per hour with electrolytes, HIIT athletes require 150-250 mL every 15 minutes, and strength trainers benefit from 200-400 mL between sets. The research shows one-size-fits-all advice fails because sweat rates, intensity, and duration differ across disciplines.
The 2026 Tour de France is in full swing, and while most fans are watching the racing, sports scientists are watching something else entirely: how 176 of the world’s best cyclists stay hydrated across 21 stages, roughly 3,400 kilometers, and 23 days in July heat. The numbers are staggering. A Tour rider can lose two … Read more
Electrolyte deficiency during training shows up as muscle cramps, sudden fatigue spikes, lightheadedness, excessive thirst despite drinking water, and slower recovery between intervals. These signs indicate you’re losing sodium, potassium, and magnesium faster than you’re replacing them—a fixable fueling problem, not a fitness issue.
Sweat primarily contains sodium (460–1,840 mg/L) and chloride (590–1,480 mg/L), with smaller amounts of potassium (160–390 mg/L), magnesium (10–36 mg/L), and calcium (40–120 mg/L). Athletes lose 500–2,000 mg of sodium per hour depending on intensity, heat, and individual sweat rates.
Mixing water and sports drinks during exercise is not only safe but often optimal. Diluting commercial sports drinks by 25-50% lets you match carbohydrate and sodium delivery to your actual sweat rate, intensity, and gut tolerance without overshooting or undershooting electrolyte needs.
The best way to calculate sweat loss is through weigh-ins before and after training: every kilogram lost equals one liter of sweat. Multiply your hourly sweat rate by sodium concentration (tested via sweat patch or estimated at 800-1200 mg/L) to determine electrolyte replacement needs per hour of exercise.