Evidence map›Paper›PMID 39179881›Full record

Trial reportEuropean journal of applied physiology2025

Dose-response effects of caffeine during repeated cycling sprints in normobaric hypoxia to exhaustion.

Yinhang Cao, Wei He, Li Ding, Tze-Huan Lei, Zachary Schlader, Toby Mundel, Ran Wang, Li Guo, Jue Liu, Olivier Girard

Abstract readRandomized Controlled Trial
PubMed Publisher
In one paragraph

Trial report in European journal of applied physiology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers, 3 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
8citing papers in PubMed, 3 pooled it
–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

8 citing papers in PubMed, 3 syntheses or guidelines pooled it.

  1. Pooled it
  2. Pooled it
  3. Pooled it
  4. Trial
  5. Trial
  6. Article
  7. Article
  8. 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

10 authors.

Yinhang CaoSchool of Athletic Performance, Shanghai University of Sport, Shanghai, People's Republic of China.ORCID http://orcid.org/0000-0003-2323-3707
Wei HeSchool of Athletic Performance, Shanghai University of Sport, Shanghai, People's Republic of China.ORCID http://orcid.org/0009-0001-1608-0709
Li DingSchool of Athletic Performance, Shanghai University of Sport, Shanghai, People's Republic of China.ORCID http://orcid.org/0009-0009-4526-4951
Tze-Huan LeiOccupational Safety and Health Group (OSHG), College of Safety Science and Engineering, Xi'an University of Science and Technology, Xi'an, People's Republic of China.ORCID http://orcid.org/0000-0003-3157-099X
Zachary SchladerDepartment of Kinesiology, Indiana University School of Public Health, Bloomington, IN, USA.
Toby MundelDepartment of Kinesiology, Brock University, St. Catharines, ON, Canada.ORCID http://orcid.org/0000-0002-4214-8543
Ran WangSchool of Athletic Performance, Shanghai University of Sport, Shanghai, People's Republic of China.ORCID http://orcid.org/0000-0002-7148-0764
Li GuoSchool of Exercise and Health, Shanghai University of Sport, Shanghai, People's Republic of China.ORCID http://orcid.org/0009-0007-1206-3614
Jue LiuDepartment of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, 200040, People's Republic of China. susanjue@126.com.ORCID http://orcid.org/0000-0003-1634-9904
Olivier GirardSchool of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Australia.ORCID http://orcid.org/0000-0002-4797-182X

Funding

Shanghai Key Lab of Human Performance at Shanghai University of Sport 11DZ2261100
6 · The paper itself

Abstract

purposeWith limited studies exploring the dose-response of caffeine consumption on repeated sprint ability in hypoxia, this study aimed to determine the optimal caffeine dose (low, moderate or high) during repeated sprints in hypoxia to exhaustion.

methodsOn separate visits, twelve active males randomly performed four experimental trials in normobaric hypoxia (inspired oxygen fraction: 16.5 ± 0.2%). Participants ingested placebo (PLA) or caffeine capsules (3, 6 or 9 mg/kg or LOW, MOD and HIGH, respectively) 1 h before exercise and then underwent a repeated cycling sprint test (10 s sprint/20 s active recovery) to exhaustion. Total sprint number and work done, peak and mean power output, blood lactate concentration, cardiorespiratory and perceptual responses were recorded.

resultsTotal sprint number was greater in MOD and HIGH compared to PLA (20 ± 7 and 18 ± 8 vs. 13 ± 4; all P < 0.05), with MOD also higher than LOW (15 ± 6; P = 0.02). Total work done was greater in MOD (111 ± 40 kJ) and HIGH (100 ± 35 kJ) compared to LOW (83 ± 29 kJ) and PLA (76 ± 25 kJ) (all P < 0.05). However, there were no significant differences in total sprint number or total work done between MOD and HIGH (all P > 0.05). Blood lactate concentration was higher in both MOD and HIGH compared to PLA (all P < 0.05). However, peak and mean power outputs, fatigue index, and ratings of perceived exertion did not differ across different caffeine dosages (all P > 0.05).

conclusionA moderate dose of caffeine (6 mg/kg) is the optimal amount for enhancing repeated cycling sprint ability when compared to low and high doses in moderate normobaric hypoxia.

Indexed as

BicyclingCaffeineCentral Nervous System StimulantsHypoxiaPhysical EnduranceAdultAthletic PerformanceDose-Response Relationship, DrugHumansLactic AcidMaleOxygen ConsumptionYoung AdultCaffeineCentral Nervous System StimulantsLactic AcidErgogenic aidsHypoxiaNutritional supplementRepeated sprint exerciseSimulated altitude

Identifiers

PMID39179881

What OpenQuestion holds

Textmetadata
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 OpenQuestion graph.