Glycogen Management¶

Glycogen Management is the strategic fuelling of the body's primary carbohydrate energy store — muscle and liver glycogen — to ensure maximum explosive capacity is available from the first point to the last. Glycogen is the fuel for the glycolytic energy system and the primary resynthesis substrate for the ATP-PC system. When it depletes, explosive performance collapses — first in the legs, then throughout the entire athletic system.

"Optimal glycogen management is about ensuring that the athlete's 'gas tank' is full before the race, being topped up during the race, and being efficiently refuelled afterwards."

Why Glycogen Is the Critical Fuel¶

The three energy systems in order of intensity: 1. ATP-PC (immediate, 0–10s) — refuelled by phosphocreatine and aerobic metabolism 2. Glycolytic (anaerobic, 10–90s) — fuelled by glycogen and glucose 3. Aerobic (sustained, >2 min) — fuelled by glycogen, fat, protein

Glycogen sits at the intersection of systems 2 and 3. A glycogen-depleted player: - Cannot sustain glycolytic output for extended rallies - Shifts to fat oxidation (aerobic) — which is 40% slower at converting fuel to ATP - Loses explosive first-step speed as the ATP-PC replenishment pathway slows - Experiences "heavy legs" — the subjective signal of glycogen-depleted quadriceps

In a 3-hour match at 25°C, an elite player can burn 1,500–2,500 kcal, with carbohydrate contributing 60–70% of total energy expenditure. Without active glycogen management, depletion begins in the second set.

The Three Phases¶

Phase 1: Pre-Match Loading (24–48 hours before)¶

The Goal: Fill glycogen stores to maximum capacity.

Carbohydrate Intake: 7–10g per kg of bodyweight per day, for 24–48 hours pre-match
Food Sources: Rice, pasta, potatoes, bread, oats — complex carbohydrates that absorb at a sustained rate
Pre-Match Meal (3–4 hours before): Low glycaemic index (GI) carbohydrates + moderate protein + minimal fat and fibre (to avoid GI distress); e.g., oatmeal + banana + chicken

The Glycogen Supercompensation protocol: After a training session that partially depletes glycogen, the body upregulates glycogen synthase — increasing its capacity to store glycogen. Consuming high-GI carbohydrates immediately after this depletion allows supercompensation, filling glycogen stores to 10–20% above baseline levels.

Phase 2: During-Match Maintenance¶

The Goal: Maintain blood glucose and slow glycogen depletion rate.

Every 45–60 minutes: 30–60g of carbohydrates (1–2 gels, a banana, or a glucose-electrolyte drink)
Changeovers: Primary window for carbohydrate intake — the 90-second changeover allows digestion to begin without GI distress during play
Blood Glucose: A drop in blood glucose mid-match triggers hypoglycaemia — dizziness, cognitive slowing, loss of shot selection. This is separate from glycogen depletion and is managed by the frequent, small carbohydrate doses during play

The Glucose-Electrolyte Drink: Simultaneously addresses glycogen maintenance AND hydration. At 4–8% carbohydrate concentration, it empties from the stomach faster than pure water and delivers glucose directly to the bloodstream.

Phase 3: Post-Match Recovery — The Golden Window¶

The Goal: Maximise glycogen resynthesis rate.

The 30-minute Golden Window immediately after exercise is when: 1. Muscle cell membranes are maximally permeable to glucose 2. Glycogen synthase activity peaks 3. Protein synthesis is elevated (muscle repair begins)

Protocol: - Carbohydrates: 1.0–1.5g per kg of bodyweight immediately post-match - Protein: 20–40g of fast-absorbing protein (whey isolate or whole food equivalent) within the same 30-minute window - Ratio: 3:1 or 4:1 carbohydrate-to-protein (e.g., 60–90g carbohydrates + 20–30g protein)

Missing the Golden Window and eating 2 hours post-match reduces glycogen resynthesis rate by approximately 50%, significantly impairing next-day readiness — critical during tournament play with consecutive match days.

Tournament-Week Glycogen Strategy¶

Day	Glycogen Protocol
Match Day (Day 1)	Loading (7–10g/kg carbs) + during-match maintenance + Golden Window
Day After Match	Moderate carbs (5–7g/kg); focus on protein for repair
Day Before Next Match	Re-loading begins; 7–10g/kg carbs
Next Match Day	Same as Match Day

During Grand Slam weeks with matches every 2 days, glycogen loading becomes continuous — players cannot afford to allow full glycogen depletion between matches.

Glycogen and Cognitive Function¶

An often-overlooked consequence of glycogen depletion is cognitive decline. The brain runs almost exclusively on glucose. When liver glycogen (the brain's primary fuel source) depletes: - Decision-making speed slows - Risk assessment degrades — the player starts going for lower-percentage shots - Emotional regulation weakens — the first signs of Self 1 intrusion under pressure often coincide with blood glucose drops

This is why Between-Point Ritual execution quality drops late in matches: the neurological substrate that powers prefrontal cortex function (impulse control, tactical planning) is becoming glycogen-depleted.

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