ISRCTN ISRCTN49860006
DOI https://doi.org/10.1186/ISRCTN49860006
Secondary identifying numbers Impact of in-session rehydration on swimming performance. Version 3
Submission date
14/07/2016
Registration date
20/07/2016
Last edited
30/08/2023
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Nutritional, Metabolic, Endocrine
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English Summary

Background and study aims
Manufacturers of sports drinks claim their products are better at rehydrating athletes than water and that they allow the athlete to perform their sport better. They use reports from studies to back up their claims. However when these studies have been examined it has been found that the methods used are much less rigorous than a study that would be required to back up the use of a new drug. The aim of this study is to find out whether drinking fluid whilst swimming can improve performance compared to not drinking, and whether drinking a sports drink improves performance more than just drinking water.

Who can participate?
Healthy adolescent competitive swimmers aged between 11 and 18 who swim five times a week at West Suffolk Swimming Club (including Fridays).

What does the study involve?
Participants are randomly allocated to receive three study conditions in a different order over 12 swimming sessions. The first condition involves not drinking anything during six swimming sessions. The second condition involves being able to drink as much water as they like during three swimming sessions. The third condition involves being able to drink as much sports drink as they like during three swimming sessions. At the end of each of the sessions, participants complete a ten 100 metre swim sprints. During the middle 50 metres of each swim sprint, the time taken is recorded. The results are then compared to see if drinking water or a sports drink improved performance.

What are the possible benefits and risks of participating?
Participants may benefit from finding a drinking plan which could boost their individual performance that they may wish to carry on with after the study. There are no notable risks involved for those participating in this study.

Where is the study run from?
West Suffolk Swimming Club (UK)

When is the study starting and how long is it expected to run for?
March 2014 to June 2015

Who is funding the study?
Investigator initiated and funded (UK)

Who is the main contact?
Dr Graham Briars
graham.briars@nnuh.nhs.uk

Contact information

Dr Graham Briars
Scientific

Paediatric Gastroenterology
Norfolk & Norwich University Hospital
Colney Lane
Norwich
NR 7 4UY
United Kingdom

ORCiD logoORCID ID 0000-0003-4798-3350
Phone +44 (0)1603 287278
Email graham.briars@nnuh.nhs.uk

Study information

Study designDouble-blind randomised cross over trial
Primary study designInterventional
Secondary study designRandomised cross over trial
Study setting(s)Other
Study typeOther
Participant information sheet ISRCTN49860006_PIS_19Jul16.pdf
Scientific titleThe Swim Drink study: a randomised controlled trial of during-exercise rehydration to enhance performance
Study hypothesisNull hypotheses:
1. There is no difference between 50 metre swim times for athletes whether they take fluid in the training session immediately preceding the test swim or not
2. There is no difference between swim times for athlete who drink in session, whether they drink water or a sports drink
Ethics approval(s)Faculty of Medicine and Health Sciences Research Ethics committee, University of East Anglia, 05/09/2014, ref: 2013/2014 - 55
ConditionDehydration
InterventionThis trial will be conducted over 12 consecutive weeks in the course of 2 hour training session held at the same time each week. Swimmers will be randomised to one of three drinking regimes for the initial 90 minutes of the session each training session. Sessions 1-12 will be conducted in a random order and swimmers will be blinded to their designation at a particular session until they have arrived on poolside. This designation will be determined by the study blinder who will play no other part in the study. Each week’s swimmer session number allocation will be released to the study team week by week to allow preparation of the week’s drinks.

Regimen one: No drink for six sessions
Regimen two: Plain water ad-libitum for three sessions
Regimen three: Selected sports drink purchased from a high street supermarket by the study team for three sessions. All swimmers will use the same sports drink.

In the drinking sessions the study drink will be take ad libitum at any time throughout the 90 minute training session. After a training program estimated to last 90 minutes swimmers will undergo the test set. Swimmers allocated to a drinking regime will be free to continue ad libitum fluid intake in between individual swims. Any violation of the drinking regime will be recorded and analysis will be on an intention to treat basis. Once the test set has been completed and swimmers and drinks bottles have been weighed all swimmers will be free to drink any fluid they wish ad libitum.
Intervention typeSupplement
Primary outcome measureTime to complete the middle 50 metres for each of ten 100 metre swim sprints in seconds using electronic timing pads at during the 30 minute test set at the end of each swimming session.
Secondary outcome measures1. Thirst is measured using a Visual Analogue Scale (VAS) at the start and end of each swimming session
2. Body weight is measured using digital electronic scales at the start and end of each swimming session
Overall study start date30/03/2014
Overall study end date02/06/2015

Eligibility

Participant type(s)Healthy volunteer
Age groupMixed
SexBoth
Target number of participants20-40 swimmers
Participant inclusion criteria1. Aged 11 to 18 years
2. Member of the West Suffolk Swimming Club
3. Trains 5 times/week
4. Trains on Friday evenings
Participant exclusion criteriaSuffering illness
Recruitment start date28/11/2014
Recruitment end date08/01/2015

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

West Suffolk Swimming Club
Bury St Edmunds
IP33 3TT
United Kingdom

Sponsor information

Norfolk and Norwich University Hospital
Other

Funders

Funder type

Other

Investigator initiated and funded

No information available

Results and Publications

Intention to publish date31/12/2016
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryOther
Publication and dissemination planPlanned publication in high impact peer reviewed journal.
IPD sharing planSubject level data are available as supplementary files to the BMJPaed open paper. They are anonymised and are not subject to any restriction on analyses. Any further inquiries can be directed to Dr Graham Briars (g.briars@doctors.org.uk).

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Participant information sheet 19/07/2016 20/07/2016 No Yes
Results article results 25/10/2017 Yes No
Dataset 25/10/2017 30/08/2023 No No

Additional files

ISRCTN49860006_PIS_19Jul16.pdf
Uploaded 20/07/2016
ISRCTN49860006_Dataset.pdf

Editorial Notes

30/08/2023: Dataset added.
15/01/2020: Internal review.
12/04/2018: Internal review.
26/10/2017: IPD sharing statement added.
25/10/2017: Publication reference added.