Nutrition · Moderate evidence
Hydration and Exercise
Dehydration exceeding approximately 2% of body weight impairs performance; fluid requirements are individual and depend on sweat rate, climate, and duration.
Scientific society position stand · 1 source · 2 min
What the studies show
- Fluid losses greater than 2% of body weight reduce performance, particularly in the heat.
- Excessive drinking beyond thirst can cause hyponatremia.
- Beverages containing sodium and carbohydrates help during long sessions.
How Letz applies it
The Letz water target serves as a routine baseline and increases on training days; it is not treated as a prescription.
Who it applies to
Active adults in any modality.
Limits
Fixed daily fluid targets lack a solid foundation; practical indicators include urine color, thirst, and body weight changes during a session.
Sources
- American College of Sports Medicine, Medicine & Science in Sports & Exercise, 2007 DOI 10.1249/mss.0b013e31802ca597
More in Nutrition
- Protein and Training AdaptationSufficient protein can support gains in lean mass and strength alongside training; the response varies and does not increase indefinitely with higher intakes.
- Higher Protein Intake During a Calorie DeficitIn a deficit, higher protein protects lean mass and can even allow muscle gain alongside intense training; the effective range rises to approximately 1.6 to 2.4 g/kg.
- Rate of weight lossLosing weight slowly, at around 0.5 to 1% of body weight per week, better preserves lean mass, strength, and metabolic rate compared to rapid weight loss.
- Distribute protein throughout the dayDividing protein into servings of around 0.4 g/kg across four or more meals stimulates protein synthesis more than concentrating everything into one or two.