Evidence map›Paper›PMID 29910346›Full record

ArticleSports (Basel, Switzerland)2018

The Effects of Sleep Extension on Sleep, Performance, Immunity and Physical Stress in Rugby Players.

Richard Swinbourne, Joanna Miller, Daniel Smart, Deborah K Dulson, Nicholas Gill

Open access · goldAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Sports (Basel, Switzerland), 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 31 papers, 3 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
31citing papers in PubMed, 3 pooled it
6.8field-weighted citation impact, top 3% of its field
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

31 citing papers in PubMed, 3 syntheses or guidelines pooled it, 70 citations in OpenAlex.

  1. Pooled it
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  14. Sleep interventions in elite sport - a systematic review.South African journal of sports medicine · 2025
    Review
  15. Article
  16. Article
  17. Review
  18. Article
  19. Sleep and Performance in Professional Athletes.Current sleep medicine reports · 2023
    Review
  20. 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

5 authors at 2 institutions in 1 country.

Richard SwinbourneFaculty of Sport and Recreation, Auckland University of Technology, Auckland 0627, New Zealand. Richard_Swinbourne@sport.gov.sg.
Joanna MillerPhysiology Department, Australian Institute of Sport, Canberra 2617, Australia. Jo.Miller@ausport.gov.au.
Daniel SmartSports Research Institute New Zealand, Auckland University of Technology, Auckland 0627, New Zealand. dan.smart@nzrugby.co.nz.
Deborah K DulsonFaculty of Sport and Recreation, Auckland University of Technology, Auckland 0627, New Zealand. deborah.dulson@aut.ac.nz.
Nicholas GillFaculty of Health, Sport and Human Performance, University of Waikato, Hamilton 3240, New Zealand. nicholas.gill@nzrugby.co.nz.
Auckland University of Technology · NZUniversity of Waikato · NZ

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

(1) Background: The purpose of the present study was to examine the efficacy of sleep extension in professional rugby players. The aims were to: (i) characterise sleep quantity in elite rugby players and determine changes in immune function and stress hormone secretion during a pre-season training programme; (ii) evaluate the efficacy of a sleep extension intervention in improving sleep, markers of physical stress, immune function and performance. (2) Methods: Twenty five highly trained athletes from a professional rugby team (age (mean ± SD) 25 ± 2.7 years; height 1.87 ± 0.07 m; weight 105 ± 12.1 kg) participated in a six week pre-post control-trial intervention study. Variables of sleep, immune function, sympathetic nervous activity, physiological stress and reaction times were measured. (3) Results: Sleep extension resulted in a moderate improvement in sleep quality scores ([mean; ± 90% confidence limits] −24.8%; ± 54.1%) and small to moderate increases in total sleep time (6.3%; ± 6.3%) and time in bed (7.3%; ± 3.6%). In addition, a small decrease in cortisol (−18.7%; ± 26.4%) and mean reaction times (−4.3%; ± 3.1%) was observed following the intervention, compared to the control. (4) Conclusions: Professional rugby players are at risk of poor sleep during pre-season training, with concomitant rises in physical stress. Implementing a sleep extension programme among professional athletes is recommended to improve sleep, with beneficial changes in stress hormone expression and reaction time performance.

Indexed as

collision sportsperformancephysical stressrecoverysleep extension

Identifiers

PMID29910346
PMCPMC6026815
OpenAlexW2800765696

What OpenQuestion 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 OpenQuestion graph.