How to prepare your body nutritionally for speed, endurance, and recovery

The race starts long before the start line

The 10 km is one of the most revealing distances in endurance sport.
Short enough to demand speed, long enough to test endurance — it exposes every weakness: pacing, recovery, and especially, nutrition.

Your diet during the final weeks before a race can make or break your performance.
Energy, digestion, focus, and even your perceived effort are all tightly connected to how you fuel your body.

This guide breaks down exactly how to prepare nutritionally — when to adjust your intake, what to eat, how to use supplements intelligently, and how to arrive on race day ready to perform at your best.

1. Start with understanding your engine

Before planning any diet, you need to know your TDEE (Total Daily Energy Expenditure) — the amount of energy you burn each day.
It depends on:

• BMR (Basal Metabolic Rate) — calories needed to keep your body alive at rest

• Activity coefficient — how much you move, train, and recover

Once you know your TDEE, you can plan your intake precisely:

💡 Hack: Use a smart calorie calculator (or your Rytme spreadsheet) to track your TDEE evolution as your training volume decreases near race week. Many runners forget to reduce overall calories while keeping carb ratios high — leading to bloating or energy dips.

2. The nutritional foundation: what to focus on every day

A well-prepared 10 km diet isn’t built in a week — it’s built through consistency.
During your training cycle, your nutrition should support recovery, performance, and resilience.

Macronutrient balance (per day, for an active runner):

These are not fixed numbers — they adapt with your mileage, intensity, and recovery needs.

3. Micronutrients: your performance insurance

While macros fuel movement, micronutrients sustain the systems behind it — oxygen transport, muscle contraction, energy metabolism, and recovery.

Core nutrients to monitor:

• Magnesium (350–400 mg/day): regulates muscle contraction and prevents cramps

• Vitamin D3 (20–70 µg/day): improves oxygen utilization and immune health

• Iron (check via blood test): critical for oxygen transport — low iron means low performance

• Calcium & Vitamin K2: support bone health and neuromuscular control

• Zinc & Vitamin C: support tissue repair and immune function

🩸 Blood test tip:
Get a blood panel 4–6 weeks before your race.
Check iron, ferritin, vitamin D, magnesium, and B12 levels.
Adjust with targeted supplementation only if deficient — more isn’t better.

4. The two-week nutrition taper

Just like you taper your training volume before a race, you should taper your nutrition — adjusting your intake to maximize glycogen stores, minimize inflammation, and stabilize digestion.

10–7 days before race day:

• Keep your calorie intake close to maintenance

• Prioritize whole carbs (rice, oats, sweet potatoes)

• Increase hydration gradually (extra 300–500 ml/day)

• Focus on nutrient density and digestion: lean protein, greens, berries, and healthy fats

6–3 days before race day:

• Increase carb intake by 10–20% to start saturating glycogen stores

• Reduce fiber slightly to avoid bloating

• Keep protein moderate, fats low

• Add salt to meals to retain electrolytes

• No drastic changes — your stomach should feel light but full

48–24 hours before race day:

• This is your carb-loading window

• Choose easy-to-digest carbs: white rice, pasta, oats, fruit, honey

• Reduce vegetables, seeds, and anything high in fiber

• Avoid alcohol and heavy fats (they slow digestion)

• Hydrate well with electrolytes

💡 Hack: Eat ~8–10 g of carbs per kg of body weight during your last 36 hours.
If you weigh 70 kg → ~560–700 g carbs spread evenly.

5. The day before the race

Think simplicity, stability, hydration.

• Eat familiar foods — nothing new.

• Keep protein moderate and fats low.

• Prioritize hydration with electrolytes.

• Avoid excessive caffeine (it can dehydrate you overnight).

• Last substantial meal: 12–14 hours before the race (e.g., dinner).

Example:

Rice, grilled chicken, olive oil, and a banana.

Add ½ tsp of salt or an electrolyte tablet in water before bed — this helps with overnight hydration.

6. Race-day nutrition

The morning of the race (3–4 hours before start):

• Eat your last full meal 3–4 hours before the start to allow digestion.

• Keep it low fiber, high carb, moderate protein, low fat.

• Drink 400–600 ml of water or electrolyte solution with breakfast.

Example breakfast (3–4h before start):

Oats with honey and banana, or white bread with jam + small yogurt.

1 hour before the race:

• Optional light snack if you feel hungry: 1 ripe banana or small energy bar.

• Sip 200–300 ml of water or electrolyte drink.

During the race (for races over 40 min):

• You can take 30–40 g of carbohydrates per hour via gels or sports drink.

• Small sips of water every 15–20 minutes (depending on temperature).

• Use electrolyte drinks or salt tabs if you sweat heavily or conditions are hot.

💡 Hack: Mix your own isotonic drink — 500 ml water + 30 g maltodextrin + pinch of salt + splash of lemon.
It hydrates faster than water alone and is easier on the stomach than commercial sports drinks.

7. Post-race recovery

Recovery starts immediately after crossing the finish line.
Your goal is to replenish glycogen, restore hydration, and repair tissue.

Within 30 minutes:

• 25–30 g of protein + 60–80 g of carbs (shake, banana, or recovery bar).

• 500–700 ml of electrolyte-rich water.

• Light stretching or walking for 5–10 min to flush lactate.

Within 2 hours:

• Full meal: rice or pasta + lean protein + vegetables + olive oil.

• Add magnesium or a mineral-rich drink to support muscle relaxation.

Avoid heavy fats, alcohol, or spicy foods immediately after.

8. Supplements that can support 10 km performance

Daily foundation (4–6 weeks before the race):

• Magnesium (350–400 mg): recovery and muscle function

• Vitamin D3 (20–50 µg): energy and immune health

• Omega-3 (EPA+DHA > 1.5 g): anti-inflammatory, joint support

• Creatine (3–5 g): helps maintain power in final kilometers

• Cordyceps sinensis (2 g/day): improves oxygen utilization and fatigue resistance

• Vitamin C + Zinc: antioxidant and immune protection

Race week add-ons:

• Electrolytes (Na+, K+, Mg++): daily, especially 2–3 days pre-race

• Beetroot juice (nitrates): start 5–6 days before race to improve oxygen efficiency

9. Common mistakes to avoid

1. Over-carbing too early → bloating and heavy legs

2. Ignoring hydration → even 2% dehydration can drop performance by 10%

3. Testing new foods or gels on race day → never experiment on game day

4. Cutting salt → leads to cramping in warm conditions

5. Skipping breakfast → low blood sugar before start leads to fatigue mid-race

6. Too much caffeine → jittery start, early crash

10. The Rytme principle: consistency before complexity

The key to a successful race isn’t magic food — it’s consistency.
You don’t perform on what you eat the night before; you perform on what you’ve built over weeks.

Train your gut like you train your legs.
Hydrate intentionally.
Test your fueling strategy during training, not during the race.
And use blood tests and awareness to personalize your approach — data replaces guesswork.

When you align your intake, training, and recovery, you move in rhythm —
the place where science meets performance.