Plain English Summary
Background and study aims
Many major international competitions for field hockey take place in hot environmental conditions (such as in the Rio 2016 Olympics). There is therefore a need to better understand how the body copes with the heat stress associated with high-intensity intermittent (stop-start) exercise and how this impacts upon field-hockey players’ physical performance and cognitive function (mental processing). Field hockey not only involves intermittent high speed running and sprinting but decision-making skills. Therefore it is important to understand how field-hockey specific exercise in hot conditions effects cognitive function. In addition, previous research from our lab has demonstrated that field hockey player compete when dehydrated, particularly during tournaments. The aim of this study is to determine whether cognitive function is impaired in hot and moderate conditions and when dehydrated following hockey specific exercise.
Who can participate?
Female elite field hockey players aged 18-40.
What does the study involve?
Participants complete four field hockey simulations in a random order, a minimum of 1 week apart, on a treadmill. Before and after each of the hockey match simulations cognitive function is assessed using laptop based software. The four simulations involve exercise in the heat in a normal hydration state; exercise in the heat when dehydrated; exercise in moderate conditions in a normal hydration state; and exercise in moderate conditions in a dehydrated state. Participants are familiarised with all the techniques and measurements during preliminary laboratory visits. For each simulation, participants have their cognitive function measured before and after each exercise test. In addition, their rectal temperature, how much they felt they are pushing themselves and thirst are measured every 10 minute during exercise.
What are the possible benefits and risks of participating?
Participants benefit from being provided with information about their current fitness levels and a training programme provided should they wish. In addition, information can be provided regarding a participant’s responses to exercising in hot conditions. Intermittent exercise in the heat is physically very demanding, and places strain on the body. Therefore, there is a risk that participants may feel faint or nauseas and/or suffer from heat stroke. All participants will be closely monitored in order to avoid this.
Where is the study run from?
Nottingham Trent University (UK)
When is the study starting and how long is it expected to run?
September 2006 to September 2008
Who is funding the study?
Nottingham Trent University (UK)
Who is the main contact?
Dr Caroline Sunderland
caroline.sunderland@ntu.ac.uk
Trial website
Contact information
Type
Scientific
Primary contact
Dr Caroline Sunderland
ORCID ID
Contact details
Erasmus Darwin Building
Nottingham Trent University
Clifton Lane
Nottingham
NG11 8NS
United Kingdom
+44 115 8486379
caroline.sunderland@ntu.ac.uk
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
FHITP
Study information
Scientific title
Effects of heat stress and dehydration on cognitive function in elite female field hockey players
Acronym
Study hypothesis
Cognitive function would be impaired when hypohydrated and under heat stress.
Ethics approval
Nottingham Trent University School of Science and Technology Human Ethics Committee, 14/11/2006, ref: xxxviii
Study design
Single-centre randomised cross over trial
Primary study design
Interventional
Secondary study design
Randomised cross over trial
Trial setting
Other
Trial type
Other
Patient information sheet
No participant information sheet available
Condition
Sports performance
Intervention
Participants are randomised to undertake four exercise conditions in a random order. The exercise undertaken consists of 50 minutes of activity, divided into 2 x 25 min blocks of exercise separated by a 10 min intermission designed to replicate half time. This is performed on a motorised treadmill (h/p/cosmos Pulsar 4.0, Nussdorf-Traunstein, Germany) housed in an environmental chamber (WIR52-20HS, Design Environmental Ltd., Gwent, Wales, U.K) and consisted of different exercise intensities observed in match-play. Participants are required to hold a hockey stick for the entire duration of the protocol. The treadmill gradient was set at 1% to reflect the energy cost of outdoor running.
Condition 1: Participants complete exercise in heat (33.3 ± 0.1oC, 59 ± 1% rh) in a dehydrated state (achieved through undergoing a period in an chamber (~ 40oC, 75% rh))
Condition 2: Participants complete exercise in heat (33.3 ± 0.1oC, 59 ± 1% rh) in a hydrated state (ingestion of water ad libitum, in a thermally neutral environment (~ 19oC) for ~ 2 hours)
Condition 3: Participants complete exercise in a thermally neutral environment (~ 19oC) in a dehydrated state
Condition 4: Participants complete exercise in a thermally neutral environment (~ 19oC) in a hydrated state
All participants are monitored closely throughout the recovery period on completion of the main trials. Participants are fed, rehydrated and only permitted to leave the laboratory once they were euhydrated, core temperature had returned to normal levels and the participants confirmed they were feeling ‘normal’.
Participants undergo computerised cognitive function assessments at baseline and 60- minutes post-exercise in all four trial conditions. Additionally, rectal temperature, perceived exertion (self-reported) and perceived thirst (self-reported) are measured at baseline and every 10 minutes throughout exercise in each condition.
Intervention type
Other
Phase
Drug names
Primary outcome measures
Cognitive function is assessed using the Stroop test, visual search (VS) test and Sternberg Working memory test before and 60 minutes after each exercise condition.
Secondary outcome measures
1. Rectal temperature recorded at baseline (time point 0) and every 10 minutes throughout exercise and immediately after completion of the final cognitive test battery in each exercise condition
2. Rating of perceived exertion on a scale of 6-20 using the Borg scale recorded at time point 0 and every 10 minutes throughout exercise in each exercise condition
3. Rating of perceived thirst (9 point scale ranging from not thirsty to very, very thirst) at time point 0 and every 10 minutes throughout exercise in each exercise condition
Overall trial start date
01/09/2006
Overall trial end date
01/09/2008
Reason abandoned
Eligibility
Participant inclusion criteria
1. 18-40 years old
2. Female elite
3. Elite field hockey players
Participant type
Healthy volunteer
Age group
Adult
Gender
Female
Target number of participants
10
Participant exclusion criteria
1. Exercise-induced asthmatics
2. History of heart problems
3. Family history of sudden death below the age of 50
Recruitment start date
01/12/2006
Recruitment end date
01/09/2007
Locations
Countries of recruitment
United Kingdom
Trial participating centre
Nottingham Trent University
Department of Sports Science
Clifton Campus
Nottingham
NG11 8NS
United Kingdom
Sponsor information
Organisation
Nottingham Trent University
Sponsor details
Erasmus Darwin Building
Clifton Lane
Nottingham
NG11 8NS
United Kingdom
+44 115 9418418
sstenquiries@ntu.ac.uk
Sponsor type
University/education
Website
Funders
Funder type
University/education
Funder name
Nottingham Trent University
Alternative name(s)
NTU
Funding Body Type
private sector organisation
Funding Body Subtype
academic
Location
United Kingdom
Results and Publications
Publication and dissemination plan
Planned publication in a peer-reviewed journal.
Intention to publish date
31/07/2017
Participant level data
Available on request
Results - basic reporting
Publication summary