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Glycogen Replenishment Estimator (post-workout)

Estimate glycogen replenishment needs from workout duration, intensity, type, body weight, current glycogen, post-workout carbs, and time since workout.

Glycogen Replenishment Estimator (post-workout)

Estimate glycogen replenishment needs from workout duration, intensity, type, body weight, current glycogen, post-workout carbs, and time since workout.

Input your post-workout data

Formula

Glycogen depletion = estimated from workout duration, intensity, and type. High-intensity and longer-duration workouts deplete more glycogen (up to 40-50% of total stores).

Glycogen needed = (body weight in kg × glycogen depletion %) × 15-20g per kg bodyweight. Total body glycogen stores are approximately 400-600g in trained individuals.

Hours to replenish = glycogen needed / (carb intake per hour × 0.7). Glycogen synthesis rate is approximately 5-7% per hour with adequate carb intake.

Glycogen replenishment is fastest in the first 2 hours post-workout (the "glycogen window"). Consuming 1-1.2g carbs per kg bodyweight within 2 hours optimizes recovery.

Steps

  • Enter workout duration (minutes).
  • Enter workout intensity (1-10 scale).
  • Select workout type.
  • Enter your body weight (lbs).
  • Enter estimated current glycogen level (0-100%, optional).
  • Enter post-workout carbohydrate intake (grams).
  • Enter hours since workout completion.
  • Review glycogen replenishment estimates and recommendations.

Additional calculations

Enter your workout data to see additional insights.

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The Definitive Guide to Glycogen Replenishment: Post-Workout Recovery Nutrition

Explore how to optimally replenish muscle and liver glycogen stores after exercise to support recovery, performance, and metabolic health.

Table of Contents: Jump to a Section

What is Glycogen?

Glycogen is the stored form of glucose in the body, primarily found in muscles (~400-500g) and liver (~100-150g). It serves as the primary fuel source during moderate to high-intensity exercise and is essential for maintaining blood glucose levels during fasting.

Muscle vs. Liver Glycogen

There are two main glycogen stores:

  • Muscle Glycogen: Used directly by muscles during exercise. Cannot be released into bloodstream. Depleted by exercise.
  • Liver Glycogen: Maintains blood glucose levels. Can be released into bloodstream. Depleted by fasting and exercise.

Glycogen Depletion During Exercise

Exercise intensity and duration determine glycogen depletion:

  • High-Intensity Exercise: Depletes glycogen rapidly (up to 25-40% per hour) due to reliance on anaerobic glycolysis.
  • Moderate-Intensity Exercise: Depletes glycogen at moderate rates (15-25% per hour) with mixed fuel use.
  • Low-Intensity Exercise: Minimal glycogen depletion (5-10% per hour) as fat oxidation dominates.
  • Duration: Longer workouts deplete more glycogen, with 90+ minute sessions potentially depleting 50-70% of stores.

Glycogen Replenishment Process

Glycogen synthesis occurs after exercise when carbohydrates are consumed:

  • Rate: Glycogen synthesis is fastest in the first 2 hours post-workout (5-7% per hour), then slows to 2-3% per hour.
  • Capacity: Maximum synthesis rate is approximately 5-7g glycogen per hour with optimal carb intake.
  • Timing: The "glycogen window" is the first 2 hours post-workout when synthesis is maximized.
  • Complete Replenishment: Takes 20-24 hours with adequate carb intake, or 48+ hours with low carb intake.

Optimal Timing and Amount

For optimal glycogen replenishment:

  • Immediate (0-2 hours): Consume 1-1.2g carbs per kg bodyweight to maximize synthesis rate.
  • Extended (2-6 hours): Continue consuming 0.8-1g carbs per kg bodyweight every 2 hours.
  • Total Daily: For complete replenishment, consume 5-7g carbs per kg bodyweight over 24 hours.
  • Carb Type: High-glycemic carbs (glucose, maltodextrin) are most effective for rapid replenishment.

Replenishment Strategies

Different strategies based on training schedule:

  • Same-Day Training: Prioritize rapid replenishment with high-glycemic carbs immediately post-workout.
  • Next-Day Training: Can use slower replenishment with whole foods and lower-glycemic carbs.
  • Multiple Sessions: For 2+ sessions per day, maximize immediate post-workout intake and continue frequent feedings.
  • Low-Carb Diets: Glycogen replenishment is slower but still occurs. May take 48-72 hours for complete restoration.

Conclusion

Glycogen replenishment is essential for recovery and subsequent performance. Consuming 1-1.2g carbs per kg bodyweight within 2 hours post-workout maximizes synthesis rate. Complete replenishment takes 20-24 hours with adequate intake. Understanding your glycogen needs based on workout type, duration, and intensity helps optimize recovery nutrition.

FAQs

What is glycogen?

Glycogen is stored glucose in muscles and liver, used as primary fuel during exercise. Replenishing glycogen after workouts is important for recovery, performance, and preventing muscle breakdown.

How much glycogen is depleted during exercise?

Depletion depends on intensity and duration. High-intensity training (HIIT, heavy lifting): 30-50% depletion. Moderate endurance (60-90 min): 40-60% depletion. Long endurance (2+ hours): 60-80% depletion. Full depletion is rare.

How much carbohydrate is needed to replenish glycogen?

Typically 1.2-1.5g carbs per kg body weight within 2 hours post-workout for optimal replenishment. For a 70kg person: 84-105g carbs. Total daily needs: 5-7g carbs per kg body weight for active individuals.

What is the glycogen replenishment window?

The "glycogen window" is the 30-60 minutes post-workout when glycogen synthesis is highest (up to 2x faster). However, adequate carbs within 2-4 hours post-workout still effectively replenish glycogen.

How long does glycogen replenishment take?

With adequate carbs: 20-24 hours for full replenishment after moderate exercise, 24-48 hours after intense/long exercise. Without adequate carbs: 3-5 days for full replenishment. Proper nutrition accelerates this significantly.

What foods are best for glycogen replenishment?

Fast-digesting carbs: white rice, potatoes, white bread, fruits, sports drinks. Include some protein (20-30g) to enhance glycogen synthesis. Avoid excessive fat/fiber immediately post-workout as it slows carb absorption.

Does protein help with glycogen replenishment?

Yes, protein (20-30g) consumed with carbs post-workout enhances glycogen synthesis by 20-30% compared to carbs alone. It also supports muscle repair. Aim for 3:1 or 4:1 carb-to-protein ratio post-workout.

What if I train again within 24 hours?

If training again within 24 hours, prioritize immediate post-workout nutrition (1.2-1.5g carbs/kg within 2 hours). Consider additional carbs throughout the day. Incomplete replenishment can affect next session performance.

Summary

This tool estimates glycogen replenishment needs from workout duration, intensity, type, body weight, current glycogen, post-workout carbs, and time since workout.

Outputs include glycogen depletion, glycogen needed, hours to replenish, replenishment coverage, status, recommendations, an action plan, and supporting metrics.

Formula, steps, guide content, related tools, and FAQs ensure humans or AI assistants can interpret the methodology instantly.

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Glycogen Replenishment Estimator (post-workout)

Estimate glycogen replenishment needs from workout duration, intensity, type, body weight, current glycogen, post-workout carbs, and time since workout.

How to use Glycogen Replenishment Estimator (post-workout)

Step-by-step guide to using the Glycogen Replenishment Estimator (post-workout):

  1. Enter your values. Input the required values in the calculator form
  2. Calculate. The calculator will automatically compute and display your results
  3. Review results. Review the calculated results and any additional information provided

Frequently asked questions

How do I use the Glycogen Replenishment Estimator (post-workout)?

Simply enter your values in the input fields and the calculator will automatically compute the results. The Glycogen Replenishment Estimator (post-workout) is designed to be user-friendly and provide instant calculations.

Is the Glycogen Replenishment Estimator (post-workout) free to use?

Yes, the Glycogen Replenishment Estimator (post-workout) is completely free to use. No registration or payment is required.

Can I use this calculator on mobile devices?

Yes, the Glycogen Replenishment Estimator (post-workout) is fully responsive and works perfectly on mobile phones, tablets, and desktop computers.

Are the results from Glycogen Replenishment Estimator (post-workout) accurate?

Yes, our calculators use standard formulas and are regularly tested for accuracy. However, results should be used for informational purposes and not as a substitute for professional advice.