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Trial registered on ANZCTR


Registration number
ACTRN12623001052628
Ethics application status
Approved
Date submitted
4/09/2023
Date registered
29/09/2023
Date last updated
8/09/2024
Date data sharing statement initially provided
29/09/2023
Type of registration
Prospectively registered

Titles & IDs
Public title
A comprehensive approach to address exercise-associated gastrointestinal syndrome: Evaluation and treatment strategies
Scientific title
A series of case studies to evaluate dietary strategies to address exercise-associated gastrointestinal syndrome in adult endurance runners.
Secondary ID [1] 310536 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Exercise associated gastrointestinal syndrome 331354 0
Condition category
Condition code
Diet and Nutrition 328103 328103 0 0
Other diet and nutrition disorders
Oral and Gastrointestinal 328174 328174 0 0
Normal oral and gastrointestinal development and function

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Research methods and procedures
There are four main quantitative phases of this project:

Trial phase 1: (about 1 weeks after recruitment)
Clinical assessment of the athlete (n=12)
Conducted by the lead researcher via home office using Zoom
Clinical assessment of the athlete (n=12) will include specific details about their GIS during exercise (i.e., type, severity, onset, timing, modality, environmental conditions, pre- and during exercise feeding and drinking habits).

Trial phase 2: At least 2 weeks after phase 1.
A laboratory-controlled simulated gastrointestinal assessment during exercise (GastroAxEx).
(This is the part to be conducted at Toi Ohomai Aquatic centre lab)
Conducted by the lead researcher plus lab assistant at Toi Ohomai.
The lead researcher is trained and experienced in exercise physiology laboratory techniques and is familiar with all of the lab assessment methods to be conducted.
The lab assistant intended to be utilised is a PhD sports and recreation student who is routinely used by the Sport and Recreation department; they are familiar with all exercise physiology and standard operating procedures used in the lab.
The trial day will be within the Aquatic centre opening hours to ensure additional support is required should any emergency arise.
A laboratory-controlled simulated gastrointestinal assessment during exercise (GastroAxEx).
Total participants for the study, n = 12
n = 1 participant for each trial (test) day
Trial day procedures
• Participants will be asked to replicate and record their typical event preparation (i.e., dietary, exercise, and sleep habits) 48-h leading into the GastroAxEx; this will include an exercise taper (no strenuous exercise 48-h before testing) and their nutritional intake leading into (i.e., 48-h prior) and during the competition (i.e., race nutrition).
• Participants will report to the laboratory 1-h before exercise commencement, after consuming their typical pre-event meal or snack 2-h beforehand. A dietary log (2-days) will be used to determine their nutritional intake, as per previously established dietary intake assessment and analysis procedures (Costa et al., 2013a,b).
• Participants will be asked to void their bladder and bowel before nude body mass measurement (behind a screened private area), provide a breath sample into a 250 mL breath collection bag (Wagner Analysen Technick, Bremen, Germany), and complete a modified visual analogue scale (mVAS) GIS assessment tool (Gaskell et al., 2019), as a baseline measure.
• Participants will then complete their individual tailored GastroAxEx. To ensure adequate exercise stress is applied, participants will run on a motorized treadmill for at least 3-h running at a self-selected intensity/ speed in thermoneutral conditions (22-23 °C). The exercise stress can be modified to simulate each athlete’s running event, e.g., if participants only run 4 or 5-hr events only, then this length of running will be replicated, or if they always increase their pace in the last 15 mins of an event, then the speed will be increased accordingly.
• Participants are to be instructed to consume their typical competition food and fluid intake (i.e., race nutrition) along the exercise protocol. During exercise food and fluid intake was recorded in real-time. Water will be available ad libitum throughout exercise, and the volume recorded.
• Capillary blood glucose, GIS and feeding tolerance, heart rate (HR), rating of perceived exertion (RPE), and thermal comfort rating (TCR) will be measured every 15 min during exercise.
• Breath-by-breath indirect calorimetry (Cortex MetaLyzer 3B, Leipzig, Germany) will be recorded every 20 mins for 5 mins during exercise and in the last 5 mins of exercise.
• Tympanic temperature (TTy) nude body mass, and GIS were recorded immediately post-exercise.
• Participants will remain seated during the recovery period and can consume water ad libitum (which will be recorded).
• GIS will be recorded every 15 min during the 3-h post-exercise period.
• Participants will be provided with a standard meal 2-h post-exercise in accordance with ethical procedures.
• Breath samples (20 ml) were analysed in duplicate (CV: 3.0%) for hydrogen (H2) and (CH4) content using a gas-sensitive analyser (Breathtracker Digital Microlyzer, Quintron, Milwaukee, Wisconsin, United States). Monash University will supply the breath sample bags and equipment. The samples will be shipped to Australia for testing. This process will be fully investigated, as it might be possible to hire an analyser in New Zealand.

Trial phase 3: (approximately 1 - 2 weeks after trial phase 2, participants will be informed of the interventions to trial over a 4-6 week period).
Therapeutic intervention phase
Conducted by lead researcher via home office using Zoom
Please note: The lead researcher is a New Zealand registered dietitian and advanced accredited Dietitian, capable and experienced with the following dietary and non-dietary interventions.
Based on the outcomes of the GastroAxEx from Phase 2, an individualised therapeutic intervention phase will be developed consisting of the following aims:
Modified pre-exercise food and fluid, gastrointestinal load and/or burden;
Maintain gastrointestinal patency during exertional stress; and
Ameliorate physiological strain to exercise stress (e.g., thermal strain and euhydration maintenance).

All intervention procedures will be practised in training and/or less important event/s, prior to using the interventions in targeted event/s.
Primary interventions for training to practice and then continue to implement for events if successful, may include the following
1. Gut-training protocol in training (i.e., participants will practice consuming up to 90g carbohydrates and 300-600mls of water, during exercise over a 2-week period. Exercise will be at least 1 hour long to enable the gut to adapt to digesting both carbohydrates and water during exercise). The aim during events is up to 90g carbs hourly during exercise and 600 mls of water – this is individualized for each participant.
2. Exogenous fuel provision within tolerance in training (if participants consume < 30 g of carbohydrate during endurance exercise, they will be encouraged to practice with higher amounts of up to 90 g hourly during exercise over a 2-week period. Exercise will be at least 1 hour long to enable the gut to adapt to digesting both carbohydrates)
3. Hydration provision within tolerance in training (if participants consume < 300 mL water hourly during endurance exercise they will be encouraged to practice with higher amounts of up to 600 mL hourly during exercise over a 2-week period. Exercise will be at least 1 hour long to enable the gut to adapt to higher fluid volumes)
4. Thermoregulation targeted and heat acclimation/acclimatization strategies (if participants plan to race in a warm (30 °C) or hot (35°C) environment, they will be encouraged to start training in warmer temperatures i.e., indoors on treadmills in controlled environments, or acclimate to the place they intend to race in for at least 2 weeks prior to an event).
5. Pre- and/or per-internal and/or external cooling strategies (if participants appear to overheat during exercise as seen by an increase in typmanic temperature, they will be encouraged to consume cool (<7°C) beverages or ice slushies or wear ice vests during training to reduce body temperature for at least 2 weeks during training).
6. Pre-exercise dietary management (depending on pre-exercise food diary analysis, participants may encouraged to reduce dietary fibre, fat, or protein to be in line with sports nutrition recommendations before endurance exercise, this may include both pre-training and pre-event meals).
7. Pharmacotherapy application (i.e., ondansetron with medical collaboration and prescription if participants suffer from nausea during exercise – usually prescribed to take during events prior to the usual onset of nausea but depending on the individual this maybe warranted for longer training sessions, and NSAID avoidance if participants take NSAID prophylactically in races).
8. Taking into account the biological sex of the athlete (Females will require calendar-based counting and use a menstrual tracking app (i.e., Clue) to track their menstrual cycles with the aim of running an event within the early follicular phase of their cycle. This may take up to 4 weeks to establish the correct menstrual phase to run an event in).
Primary intervention for the two days before an event will include the following
10. 48-h HCLF dietary control [i.e., low fermentable oligo- di- mono- saccharide and polyols (FODMAP)], prescribed by the lead researcher (participants will be provided with several interventions as above to practice during training, and then they will be advised on how to consume a high carbohydrate low FODMAP diet before an event. Dietary guidelines and a suggested meal plan will be provided).

Trial phase 4: (After trial phase 3, participants will be trialing interventions for at least 4 - 6 weeks. This may involve 1 - 2 follow-ups by the lead researcher to check with the participants how the interventions are progressing. This will take 4 - 6 weeks).
Monitoring and readjustment of intervention
Conducted by lead researcher (Rachel Scrivin) via home office using Zoom
To monitor and check the following;
1. Checking the athlete was healthy (i.e., free from gastrointestinal diseases and/ or disorders unrelated to exercise prior to the intervention),
2. Adherence to the dietary intervention,
3. Gut-training compliance,
4. Food and fluid intake during exercise tolerance,
5. Thermal strain targeted strategy tolerance and compliance,
6. Menstrual status where applicable (i.e., the female athlete).
In addition, measuring and recording GIS during exercise, physiological variables, and environmental conditions in training and/or competition where possible, checking other potential triggers (e.g., nutritional supplementation and anti-inflammatory medication), and assessing whether further gastrointestinal assessment at rest and during exercise is warranted (i.e., medical procedures for gastrointestinal disease/disorder diagnosis, gut microbiota composition, luminal pathogenic assessment (e.g., fungal, bacterial, parasitic, and/or allergen), specific food allergen or intolerance).

Participants and how they are recruited
Participants (n = 12) will be recruited through researcher contacts (i.e., Dietitians NZ social media pages, Sports Dietitians Special interest group contacts, and various local endurance running pages such as Papamoa running buddies Facebook page).

Participants will be required to attend an initial 1-hr online Zoom session for clinical assessment to determine study inclusion, followed by a subsequent 7-hr GastroAxEx trial day and at least 2 x 1-hr Zoom follow-up sessions.
Intervention code [1] 326928 0
Treatment: Other
Comparator / control treatment
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 335973 0
Any change in exercise-associated gastrointestinal symptoms for endurance runners - using a validated modified visual analogue scale
Timepoint [1] 335973 0
After the initial simulated laboratory run (GastroAxEx) participants will compete in a running event between 4 and 6 weeks post-intervention commencement.
Secondary outcome [1] 426322 0
Any change in running performance, e.g., participants' usual running pace compared to post-intervention running pace using GPS trackers (pace and distance completed)
Timepoint [1] 426322 0
4 and 6 weeks post-intervention commencement
Secondary outcome [2] 426662 0
Heart rate changes during exercise by using participants usual heart rate monitors (Garmin or other heart rate monitor - participants usual device)
Timepoint [2] 426662 0
4 and 6 weeks post-intervention commencement
Secondary outcome [3] 426663 0
Changes in self-perceived ratings of perceived exertion (Borg RPE scale).
Timepoint [3] 426663 0
4 and 6 weeks post-intervention commencement

Eligibility
Key inclusion criteria
Endurance runners aged 18 - 55 years who can run for 3 hours but experience gastrointestinal symptoms such as burping, urge to defecate, nausea, when running.
Minimum age
18 Years
Maximum age
55 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
• Any diagnosed gastrointestinal (GI) infections, diseases or disorders of the GI tract (e.g., IBS, inflammatory bowel disease, coeliac disease, or any other functional GI disorder), or undiagnosed self-reported GI issues experienced independently of exercise.
• If participants have consumed non-steroidal anti-inflammatory or stool-altering medications (e.g., laxatives, anti-diarrhoeal or stool softeners) within one month of the GastroAxEx
• If participants are following a dietary programme focussed on any changes to the GI function (e.g., a low FODMAP diet, low residue, or fibre-modified diets) or CHO manipulated diets (i.e., low CHO high-fat diets)
• If participants have been consuming any potential modifiers or enhancers of GI integrity (e.g., probiotics, prebiotics, symbiotic, or antibiotics) in the three months before testing.
• Any medical conditions that may be contraindicated to an exercise test, e.g., Diabetes, heart disease.

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis
From a translational professional practice perspective, data will be presented as full values for individual responses for all measured primary and secondary variables (e.g., heart rate, ratings of perceived exertion, GIS). Data in the text and tables will be presented as mean ± standard deviation (SD) or 95% confidence interval (CI). As previously reported, a summative accumulation of the severity rating score, with individual participant ranges for GIS, will be used. Data in the figures will be presented as mean ± standard error of the mean (SEM). Before data analysis, potential outliers will be identified by box and whisker plots and removed. All data will be checked for normal distribution using the Shapiro-Wilks test for normality checking skewness and kurtosis coefficients. Continuous data with singular data points will be analysed using paired sample t-tests (or nonparametric Wilcoxon signed-rank test equivalents), while variables with multiple data points will be examined using a two-way repeated-measures analysis of variance (ANOVA). Physiological strain index (PSI) will be calculated using Tty (tympanic temperature) and HR (heart rate) at pre- and post-exercise time points (PSI = (5(Tty - Tty)/ (39.5 - Tty0)) + ((HRt - HR0)/ (180 - HR0)). Statistics will be analysed using IBM SPSS statistical software (V.29.0, IMB Corp., Armonk, N.Y., USA) with significance accepted at p = 0.05.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
1/11/2023
Actual
6/11/2023
Date of last participant enrolment
Anticipated
11/12/2023
Actual
11/11/2023
Date of last data collection
Anticipated
29/02/2024
Actual
1/03/2024
Sample size
Target
12
Accrual to date
Final
11
Recruitment outside Australia
Country [1] 25753 0
New Zealand
State/province [1] 25753 0
Bay of Plenty

Funding & Sponsors
Funding source category [1] 314737 0
Government body
Name [1] 314737 0
Toi Ohomai/ Te Pukenga
Country [1] 314737 0
New Zealand
Primary sponsor type
Individual
Name
Rachel Scrivin
Address
Toi Ohomai/ Te Pukenga, 90 Poike Road Windermere Tauranga 3110
Country
New Zealand
Secondary sponsor category [1] 316717 0
None
Name [1] 316717 0
Address [1] 316717 0
Country [1] 316717 0
Other collaborator category [1] 282808 0
University
Name [1] 282808 0
The University of the Sunshine Coast
Address [1] 282808 0
90 Sippy Downs Dr, Sippy Downs QLD 4556, Australia
Country [1] 282808 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 313747 0
Central Health and Disability Ethics Committee New Zealand
Ethics committee address [1] 313747 0
Ethics committee country [1] 313747 0
New Zealand
Date submitted for ethics approval [1] 313747 0
05/07/2023
Approval date [1] 313747 0
28/07/2023
Ethics approval number [1] 313747 0
Ethics committee name [2] 313748 0
Toi Ohomia Research Ethics Committee
Ethics committee address [2] 313748 0
Ethics committee country [2] 313748 0
New Zealand
Date submitted for ethics approval [2] 313748 0
26/06/2023
Approval date [2] 313748 0
11/08/2023
Ethics approval number [2] 313748 0
23023

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 129226 0
Mrs Rachel Scrivin
Address 129226 0
Toi Ohomai, 90 Windermere Road, Poike, Tauranga 3110
Country 129226 0
New Zealand
Phone 129226 0
+64 220859959
Fax 129226 0
Email 129226 0
[email protected]
Contact person for public queries
Name 129227 0
Rachel Scrivin
Address 129227 0
Toi Ohomai, 90 Windermere Road, Poike, Tauranga 3110
Country 129227 0
New Zealand
Phone 129227 0
+64 220859959
Fax 129227 0
Email 129227 0
[email protected]
Contact person for scientific queries
Name 129228 0
Rachel Scrivin
Address 129228 0
Toi Ohomai, 90 Windermere Road, Poike, Tauranga 3110
Country 129228 0
New Zealand
Phone 129228 0
+64 220859959
Fax 129228 0
Email 129228 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
This is a series of case studies based on observational studies. Any data will be anonymous.


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
20239Study protocol    386542-(Uploaded-04-09-2023-14-29-48)-Study-related document.docx
20240Informed consent form    386542-(Uploaded-04-09-2023-14-30-13)-Study-related document.doc
20242Ethical approval    386542-(Uploaded-04-09-2023-14-34-16)-Study-related document.pdf
20243Ethical approval    386542-(Uploaded-04-09-2023-14-34-37)-Study-related document.pdf



Results publications and other study-related documents

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No documents have been uploaded by study researchers.

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No additional documents have been identified.