Category

Nutrition & Fueling

Hyper-fueling protocols, gut training, sodium, caffeine, race-week loading.

9 articles · sorted by most recent

General Endurance

How Long Does Gut Training Take to Work? The 2-Week Protocol, Explained

Two weeks of daily carbohydrate practice cuts breath hydrogen by up to 54% and GI symptoms by up to 63%, using the exact dose from the research.

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AO
AthleteOS Data Science
General Endurance

How Much Protein Per Meal Do Endurance Athletes Need? The 2025 Meta-Analysis Answer

Endurance athletes need about 0.25 g/kg protein per meal (19-24g) and roughly 0.5 g/kg (33-48g) right after hard sessions, per a 2025 meta-analysis of 75 trials.

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AO
AthleteOS Data Science
Running

Programmed vs. Thirst-Driven Hydration in Ultras — What a 2025 Narrative Review Actually Concludes

A 2025 University of Arkansas review of 6 ultra-endurance studies found neither drinking schedule nor thirst alone wins. A sweat-rate floor plus thirst ceiling is the evidence-based answer.

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AO
AthleteOS Data Science
General Endurance

Train Low, Compete High: The Carbohydrate Periodization Strategy That Actually Improves Endurance Adaptation

Train low, compete high works — but only on specific session types. The Marquet sleep-low protocol improved 10-km run time 2.9% with zero change in total carb intake.

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AO
AthleteOS Data Science
General Endurance

Energy Availability: Why Under-Fueling Makes Endurance Athletes Slow

Under-fueling to get lean makes you slower, not lighter. Energy availability below 30 kcal/kg FFM/day cuts swim speed by 9.8% in 12 weeks and costs athletes 22+ training days a year.

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AO
AthleteOS Data Science
Running

Carbohydrate Loading Before a Marathon: The 3-Day Protocol That Actually Works

One pasta dinner does almost nothing. A real carbohydrate loading protocol runs 3 days at 8–12 g/kg/day and can push your glycogen stores 84% above baseline.

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AO
AthleteOS Data Science
Triathlon

Gut Training to 120 g/hr: The Real Mechanism Isn't Glycogen Sparing

Training your gut to absorb 120 g/hr cuts muscle damage markers by 67% — not because it spares glycogen, but because it prevents breakdown. Here's the 4-week protocol.

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AO
AthleteOS Coaching Team
General Endurance

Sodium Bicarbonate for Endurance: The 1–3% Performance Hack (and the Sodium Math Nobody Mentions)

Sodium bicarbonate improves performance by 1.7% across 38 studies — but a standard 0.3 g/kg dose delivers ~5,700 mg of sodium, more than twice the US daily reference intake.

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AO
AthleteOS Coaching Team
Triathlon

Sodium for Heavy Sweaters: How to Calculate Your Real Replacement Need

Generic 300–600 mg/hr sodium guidelines fail the top 20–30% of sweaters. A 10x range in sweat sodium concentration means two athletes in the same race can need 4x different amounts.

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AO
AthleteOS Coaching Team

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