High carbohydrate intake significantly increases skeletal muscle glycogen in recreationally active and endurance trained athletesHigh carbohydrate intake boosts muscle glycogen for endurance athletes

Scandinavian journal of medicine & science in sports Published October 7, 2026 Study authors: Jones R O, Areta J L, Fortis H O, Pugh J, Louis J B PubMed ↗ DOI ↗ Editorial oversight: Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

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Key Takeaway

Note that high carbohydrate intake (> 6.5 g·kg·day) is associated with significantly higher muscle glycogen stores.

This meta-analysis evaluated the relationship between dietary carbohydrate (CHO) intake and skeletal muscle glycogen concentrations in 641 recreationally active and endurance trained individuals. The study compared low-moderate CHO intake (< 6.5 g·kg·day) against high-very high intake (> 6.5 g·kg·day).

Key findings indicate a significant positive relationship between relative CHO intake and muscle glycogen in both recreationally active (r = 0.332, p < 0.001) and endurance trained (r = 0.490, p < 0.001) populations. Specifically, increasing intake from low-moderate to high-very high levels resulted in a significant increase in muscle glycogen of +191.9 mmol·kg DM (95% CI: 142.8 to 241.1; p < 0.0001).

The authors noted significant heterogeneity in muscle glycogen concentration (I = 94%, p < 0.0001) and identified confounding variables in previous research as limitations. While the data suggests that consuming > 8 g·kg·day for 36-48 h pre-competition may increase stores, the certainty of these recommendations is tempered by the observed heterogeneity and the association-based nature of the findings.

When you are training for a long race or a big competition, your muscles need a steady source of energy. This energy comes from glycogen, which is how your body stores carbohydrates. A large review of data from 641 people, including both recreational and endurance-trained individuals, looked at how different amounts of carbohydrates affect these muscle stores.

The findings show a clear link between what you eat and how much glycogen your muscles hold. People who consumed high amounts of carbohydrates had significantly higher muscle glycogen levels compared to those who ate lower amounts. This effect was even more pronounced in those who were specifically trained for endurance sports.

While the data shows a clear link, some factors make the results less certain. There was a lot of variation in the data across different studies, and other factors could have influenced the results. However, the evidence suggests that for those looking to maximize their stores, a high-carbohydrate intake is a key factor for preparation.

What this means for you:

Higher carbohydrate intake significantly increases muscle glycogen levels for both recreational and endurance athletes.

Common questions

How much carbohydrate should I eat to increase muscle glycogen?

To significantly increase muscle glycogen stores before a competition, athletes should consume more than 8 grams of carbohydrates per kilogram of body weight for 36 to 48 hours before the event.

Does training status change how much glycogen I store?

Yes, the study found a significant relationship between carbohydrate intake and muscle glycogen in both recreationally active people and those specifically trained for endurance sports.

Can I increase my glycogen levels faster with specific exercises?

Combining exercise that depletes glycogen with high glycemic index carbohydrates can lead to a faster increase in muscle stores within 24 to 36 hours.

Study Details

Study typeMeta analysis

Sample sizen = 641

EvidenceLevel 1

PublishedOct 2026

PMID42828472

View Original Abstract ↓

A high dietary carbohydrate intake in the days pre-competition is recommended to optimize glycogen stores for endurance exercise performance. However, previous reports show high variability in muscle glycogen concentrations between individuals following similar CHO intakes. Therefore, the amount of CHO, duration, and amount of exercise required to maximize glycogen stores pre-competition remains unclear. The aim of this systematic review and meta-analysis was to determine the relationship between dietary CHO availability and skeletal muscle glycogen, whilst identifying the effect of other covariates on muscle glycogen concentration. The analysis included trials (randomized or non-randomized from five online databases) published until June 2026, that reported CHO intake and exercise for ≥ 24 h prior to collection of muscle samples using biopsies to measure skeletal muscle glycogen. Included studies were assessed descriptively and quantitatively using linear and non-linear regression, and generic inverse-variance random-effects meta-analyses, including subgroups to investigate heterogeneity. Descriptive synthesis included 63 trials (n = 641 participants), 18 were included within the meta-analysis. Exploratory linear regression indicated a significant relationship between relative CHO intake and whole muscle glycogen for recreationally active (r = 0.332, p < 0.001) and endurance trained individuals (r = 0.490, p < 0.001). Meta-analyses revealed increased dietary CHO intake from a low-moderate (< 6.5 g·kg·day) to a high-very high intake (> 6.5 g·kg·day) significantly increased muscle glycogen concentrations (+191.9 mmol·kg DM, 95% CI from 142.8 to 241.1 mmol·kg DM, p < 0.0001) but displayed significant heterogeneity (p < 0.0001, I = 94%). The delta CHO intake between study conditions (expressed as relative g·kg·day and absolute g·day) and duration of CHO loading interventions suggested a significant subgroup effect (p < 0.05) but failed to explain the heterogeneity in muscle glycogen concentration. Glycogen concentration primarily depends on quantity of CHO intake, with period of increased CHO intake, participant training status, and exercise all being key effectors. Based on current findings, to significantly increase pre-competition muscle glycogen stores athletes should consume > 8 g·kg·day for 36-48 h pre-competition, with prior glycogen depleting exercise combined with consumption of high glycaemic index CHO allowing more rapid enhancement of stores (24-36 h). However, significant heterogeneity and confounding variables in previous research introduce uncertainty in these recommendations, and further well-controlled studies are required to determine the true optimal pre-exercise CHO intake to maximize glycogen concentrations.

High carbohydrate intake significantly increases skeletal muscle glycogen in recreationally active and endurance trained athletesHigh carbohydrate intake boosts muscle glycogen for endurance athletes

Common questions

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High carbohydrate intake significantly increases skeletal muscle glycogen in recreationally active and endurance trained athletesHigh carbohydrate intake boosts muscle glycogen for endurance athletes

Common questions

Study Details

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