Evidence map›Paper›PMID 41305577›Full record

ReviewNutrients2025

Hydration Strategies in Ultra-Endurance Running: A Narrative Review of Programmed Versus Thirst-Driven Approaches.

Shawn C Wierick, Rosie I Perez, Xiujing Zhao, Brendon P McDermott

Abstract readReview
In one paragraph

Review in Nutrients, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing 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

2 citing papers in PubMed.

  1. Article
  2. Review
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.

Shawn C WierickHeat & Hydration Optimization (H2O) Laboratory, Exercise Science Research Center, University of Arkansas, Fayetteville, AR 72701, USA.
Rosie I PerezHeat & Hydration Optimization (H2O) Laboratory, Exercise Science Research Center, University of Arkansas, Fayetteville, AR 72701, USA.
Xiujing ZhaoHeat & Hydration Optimization (H2O) Laboratory, Exercise Science Research Center, University of Arkansas, Fayetteville, AR 72701, USA.
Brendon P McDermottHeat & Hydration Optimization (H2O) Laboratory, Exercise Science Research Center, University of Arkansas, Fayetteville, AR 72701, USA.ORCID 0000-0001-7238-8145

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

BACKGROUND/

objectivesUltra-endurance running (UER) presents unique hydration challenges due to prolonged duration, variable terrain, environmental extremes, and gastrointestinal limitations. Athletes often use either programmed fluid intake (PFI), which prescribes fluid volumes based on estimated sweat rate, or thirst-driven fluid intake (TDFI), which relies on internal cues. This review examines the effectiveness and limitations of each strategy in the context of UER performance and safety.

methodsA narrative review was conducted using a targeted selection of peer-reviewed studies. Both laboratory- and field-based research were included to evaluate the physiological rationale, practical feasibility, and outcomes associated with PFI and TDFI. A total of six studies (five field-based ultra-endurance and one laboratory-based endurance protocols) were included for narrative synthesis.

resultsLaboratory trials support PFI for preserving plasma volume, reducing cardiovascular strain, and improving performance in prolonged exercise under controlled conditions. However, real-world ultra-endurance events often involve environmental and logistical challenges that limit the applicability of rigid hydration strategies. Field studies demonstrate that TDFI is safe and effective for many experienced athletes, with no increased incidence of exercise-associated hyponatremia or measurable performance impairment, even with moderate body mass loss. Still, TDFI may underperform in individuals with high sweat rates or impaired thirst perception.

conclusionsNeither strategy seems universally superior. A hybrid model that integrates individual sweat testing, environmental context, and responsiveness to internal cues may offer the most practical and effective hydration approach in ultra-endurance running. Continued research is needed to validate hydration strategies under field conditions and to inform personalized, performance-oriented guidelines.

Indexed as

DehydrationDrinkingPhysical EnduranceRunningThirstAthletesAthletic PerformanceHumansSweatingdehydrationendurance performanceexercise-associated hyponatremiaprogrammed fluid intakesports nutritionthirst-driven fluid intakeultramarathon

Identifiers

PMID41305577
PMCPMC12655799

What Socratic holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

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.