Evidence map›Paper›PMID 41723749›Full record

ArticleJournal of the International Society of Sports Nutrition2026

Seasonal changes in energy intake and emerging indicators of energy availability in young elite Nordic skiers.

Helge Einar Lundberg, Stig Larsen, Jorunn Sundgot-Borgen, Therese Fostervold Mathisen

Abstract read
In one paragraph

Article in Journal of the International Society of Sports Nutrition, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors.

Helge Einar LundbergNorwegian School of Sport Sciences, Oslo, Norway.ORCID 0000-0003-3430-9068
Stig LarsenMeddoc Research A/S (MR), Skjetten, Norway.ORCID 0000-0003-1751-0026
Jorunn Sundgot-BorgenNorwegian School of Sport Sciences, Oslo, Norway.
Therese Fostervold MathisenNorwegian School of Sport Sciences, Oslo, Norway.ORCID 0000-0003-3687-583X

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundNordic skiing, an energy-demanding endurance sport, may be particularly susceptible to low energy availability (LEA) and relative energy deficiency in sport (REDs). The objective was to examine the nutritional practices and physical symptoms associated with (REDs among young elite Norwegian Nordic skiers during the off-season, with particular emphasis on energy and CHO intake, in the transition from the competitive season to preparation for the subsequent season.

methodsThirty female and thirty male Nordic skiers participated in a 24-week controlled clinical trial. The daily dietary intake variables were carbohydrates (CHO), protein, and calcium (Ca) intake and weekly training hours. The blood variables were vitamin D, total osteocalcin (tOC), procollagen type 1 N-terminal propeptide/cross-linked C-telopeptide type 1-collagen (PINP1/CTX1) ratio, heart rate (HR), resting metabolic rate (RMR), bone mineral density (BMD), lean body mass (LM), visceral adipose tissue (VAT), and body fat percentage (BF%).

resultsEnergy intake increased by 25%, and CHO increased by 14.5% for both sexes during the study, and training volume increased by 41% for female athletes and 83% for male athletes, respectively. There were positive correlations between higher BMD, bone markers, RMR, and LM and negative correlations between VAT and REDs symptoms. VAT was correlated with RMR and bone markers. LM emerged as a key predictor for health variables, explaining variability across multiple REDs markers.

conclusionsNordic skiers seem unable to increase energy intake sufficiently during the preparation period, leading up to the competitive season, as demonstrated by a large discrepancy between changes in energy intake, especially CHO, and exercise volume. The correlations between energy intake and BMD, RMR, VAT, and HR underscore the clinical consequences of insufficient energy intake, which may arise if individuals focus on low body mass and body fat percentage without sufficient knowledge. VAT, tOC, and the P1NP/CTX-ratio are promising indicators for monitoring dietary interventions in individuals with REDs and should be considered in future research on REDs treatment strategies.

Indexed as

Energy IntakeSeasonsSkiingSports Nutritional Physiological PhenomenaAdolescentBiomarkersBone DensityCalcium, DietaryCollagen Type IDietary CarbohydratesDietary ProteinsEnergy MetabolismFemaleHeart RateHumansMaleBiomarkersCalcium, DietaryCollagen Type IDietary CarbohydratesDietary ProteinsOsteocalcinVitamin Dendurance athletesenergy availabilitylean massREDsvisceral adipose tissue

Identifiers

PMID41723749
PMCPMC12927391

What Socratic holds

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LicenceCC BY-NC
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.