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Trial registered on ANZCTR


Registration number
ACTRN12620000684921
Ethics application status
Approved
Date submitted
12/05/2020
Date registered
16/06/2020
Date last updated
16/06/2020
Date data sharing statement initially provided
16/06/2020
Date results information initially provided
16/06/2020
Type of registration
Retrospectively registered

Titles & IDs
Public title
The Impact of High-Intensity Interval Training Exercise on Breast Cancer Survivors: A Pilot Study to Explore Fitness, Cardiac Regulation and Biomarkers of the Stress Systems
Scientific title
The Impact of High-Intensity Interval Training Exercise on Breast Cancer Survivors: A Pilot Study to Explore Fitness, Cardiac Regulation and Biomarkers of the Stress Systems
Secondary ID [1] 301264 0
None
Universal Trial Number (UTN)
U1111-1251-9447
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Breast Cancer 317434 0
Condition category
Condition code
Cancer 315529 315529 0 0
Breast

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Seventeen participants (62 ± 8 years) were randomly assigned to; 1) high intensity interval training (HIIT; n = 6); 2) moderate-intensity, continuous aerobic training (CMIT; n = 5); or 3) a wait-list control (CON; n = 6) for a 12-week (36 session) stationary cycling intervention. Cardiorespiratory fitness (VO2peak), resting HRV and salivary biomarkers were measured at baseline 2-4 d pre-intervention and 2-4 d post the last exercise session.

Exercise groups
Participants in the two exercise interventions attended the University of Canberra laboratory three times per week for twelve weeks (up to 36 sessions). Participants could choose from a series of scheduled timeslots where supervision was provided across the week and where compliance could be recorded. Each session was conducted on the Monark cycle ergometer and lasted 20-30 mins depending on the allocated intervention group. Participant numbers in each session were between 1 and 4 dependent on number of participants attending at each session.

Sessions were fully supervised by an experienced Accredited Exercise Physiologist or Accredited Exercise Scientist. Participant’s heart rate (HR) was continuously measured and recorded during all exercise sessions using a heart rate monitor (Polar FT40, Finland). Rating of perceived exertion (RPE) was monitored and recorded throughout each session (Borg 6-20). Exercise sessions started and finished with a 5-minute warm up and cool down, completed on the cycle ergometers at ~50% of their maximal power (watts) achieved in the baseline incremental exercise test.

The CMIT group cycled for 30 minutes in total, with 20 minutes at 55-65% of their maximal power. The workload was adjusted over 12 weeks within this range to ensure their RPE remained between 9 and 13 on the Borg scale . The HIIT group completed seven 30 second intervals (as hard as they could) with 2 minutes of active recovery between each. Participants were instructed to increase their cadence to between 95 and 115 RPM to ensure consistent performance. Participants initially completed four intervals in each session, and this was gradually increased to achieve the target of seven intervals by week four.

Control group
Participants in the waitlisted control group (CON) were asked to continue with their current lifestyle for 12 weeks after the baseline tests. After completion, the participants from the CON group were offered the 12 week fully supervised intervention.
Intervention code [1] 317567 0
Rehabilitation
Intervention code [2] 317653 0
Lifestyle
Comparator / control treatment
Participants in the waitlisted control group (CON) were asked to continue with their current lifestyle for 12 weeks after the baseline tests. After completion, the participants from the CON group were offered either of the HIIT or CMIT or a mix of both over the 12 week fully supervised intervention.
Control group
Active

Outcomes
Primary outcome [1] 323777 0
Cardiorespiratory fitness
Assessment of maximal aerobic power
A maximal graded incremental cycling test was conducted to determine VO2 Peak, intervention relative intensity and pre and post intervention fitness levels (High-Performance Ergometer, Schoberer Rad MeBtechnik, Germany). Participants respired through an oro-nasal mask (Hans-Rudolph 7450 Series V2TM Mask, CareFusion, France), breath by breath cardiopulmonary data (Vyntus CPX, Metabolic Cart, Jaeger, Germany) were measured to calculate VO2Peak in the cardiopulmonary exercise test. Throughout the test an Accredited Exercise Physiologist monitored participants with 12-Lead electrocardiogram (ECG). Blood pressure was assessed via sphygmomanometry and was recorded every two minutes.

The protocol commenced with a five minute warm up at 20 watts. Thereafter, the workload was increased by = 20 watts each minute until three of the following criteria were reached: 1) no change in oxygen consumption with increasing workload, 2) respiratory exchange ratio > 1.1, 3) heart rate within 10% of age predicted maximal heart rate or, 4) inability to maintain pedalling cadence. Participants self-selected peddling cadence > 60 revolutions per minute. In addition, exercise was terminated on the presentation of volitional fatigue, abnormal changes in blood pressure, or ECG abnormalities.


Timepoint [1] 323777 0
Participants were asked not to consume food or caffeine or participate in exercise within two hours prior to pre-and post-testing.
Secondary outcome [1] 382856 0
Heart rate variability was assessed using a Suunto watch and chest belt (Suunto model t6, Finland) and HRV was analysed using software (Kubios heart rate variability software version 2.0; Biosignal Analysis and Medical Imaging Group, Department of Physics, University of Kuopio, Kuopio, Finland).
Timepoint [1] 382856 0
Participants were asked not to consume food or caffeine or participate in exercise within two hours prior to pre-and post-testing. Assessments were carried out within the 2-4 days prior to commencement of the program and within 2-4 days following completion. HRV and salivary biomarker measures were taken prior to cardiorespiratory fitness testing.
Secondary outcome [2] 383243 0
Saliva samples (s-AA) were obtained using IPRO Oral Fluid Collection (OFC) kits that were labelled and provided to each participant. The OFC kits collect 0.5mL of oral fluid and contain a colour changing volume adequacy indicator within the swab, giving collection times typically in the range of 20-50 seconds.

Baseline saliva samples were collected at two-time points on the same day at home, two days before and after the intervention commenced and ended (immediately upon waking whilst still in bed and 30 min post waking). The participants received training on the saliva collection procedure during their first visit to the laboratory. They were requested to adhere as closely as possible to the standardised collection guidelines, which was carried out in their home. Participants recorded the time each saliva sample was collected. All samples were frozen immediately after collection in home freezers and kept frozen until reaching the laboratory, upon which they were stored at -20 °C until analysis.
Timepoint [2] 383243 0
Participants were asked not to consume food or caffeine or participate in exercise within two hours prior to pre-and post-testing. Assessments were carried out within the 2-4 days prior to commencement of the program and within 2-4 days following completion. HRV and salivary biomarker measures were taken prior to cardiorespiratory fitness testing.
Secondary outcome [3] 383586 0
Saliva samples (s-IgA) were obtained using IPRO Oral Fluid Collection (OFC) kits that were labelled and provided to each participant. The OFC kits collect 0.5mL of oral fluid and contain a colour changing volume adequacy indicator within the swab, giving collection times typically in the range of 20-50 seconds.

Baseline saliva samples were collected at two-time points on the same day at home, two days before and after the intervention commenced and ended (immediately upon waking whilst still in bed and 30 min post waking). The participants received training on the saliva collection procedure during their first visit to the laboratory. They were requested to adhere as closely as possible to the standardised collection guidelines, which was carried out in their home. Participants recorded the time each saliva sample was collected. All samples were frozen immediately after collection in home freezers and kept frozen until reaching the laboratory, upon which they were stored at -20 °C until analysis.
Timepoint [3] 383586 0
Participants were asked not to consume food or caffeine or participate in exercise within two hours prior to pre-and post-testing. Assessments were carried out within the 2-4 days prior to commencement of the program and within 2-4 days following completion. HRV and salivary biomarker measures were taken prior to cardiorespiratory fitness testing.
Secondary outcome [4] 383587 0
Saliva samples (s-cortisol) were obtained using IPRO Oral Fluid Collection (OFC) kits that were labelled and provided to each participant. The OFC kits collect 0.5mL of oral fluid and contain a colour changing volume adequacy indicator within the swab, giving collection times typically in the range of 20-50 seconds.

Baseline saliva samples were collected at two-time points on the same day at home, two days before and after the intervention commenced and ended (immediately upon waking whilst still in bed and 30 min post waking). The participants received training on the saliva collection procedure during their first visit to the laboratory. They were requested to adhere as closely as possible to the standardised collection guidelines, which was carried out in their home. Participants recorded the time each saliva sample was collected. All samples were frozen immediately after collection in home freezers and kept frozen until reaching the laboratory, upon which they were stored at -20 °C until analysis.
Timepoint [4] 383587 0
Participants were asked not to consume food or caffeine or participate in exercise within two hours prior to pre-and post-testing. Assessments were carried out within the 2-4 days prior to commencement of the program and within 2-4 days following completion. HRV and salivary biomarker measures were taken prior to cardiorespiratory fitness testing.

Eligibility
Key inclusion criteria
Participants were included in this study if they were; (1) females between the ages of 50 and 75 years, (2) sedentary as classified by the American College of Sports Medicine, (3) were within two years post-cancer treatment and (4) did not take blood pressure medication (angiotensin-converting enzyme inhibitors or angiotensin receptor blockers or calcium channel blockers or beta-blockers), (5) did not have brain or bone metastasis or (6) a diagnosis of secondary cancers and (7) were able to perform the exercise sessions on a stationary cycle ergometer (Monark 828E Ergometer).
Minimum age
50 Years
Maximum age
75 Years
Gender
Females
Can healthy volunteers participate?
No
Key exclusion criteria
Anyone taking blood pressure medication
Brain or bone metastasis
A diagnosis of secondary cancers
Unable to perform exercise sessions on a stationary cycle

Study design
Purpose of the study
Educational / counselling / training
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
After baseline testing a sealed envelope with the group allocation was given to the participant.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
A concealed, computer-generated sequence of numbers in blocks of variable sizes (3, 6, 9) in a 1:1:1 ratio for the three intervention groups stratified by age (<60 years and = or > 60 years) was generated by a researcher not involved (blinded) in the study.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Pilot three-arm RCT
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
The data were analysed with a general linear mixed model using the R package lme4 (R Core Team 2018). A random intercept for participants was included to account for intraindividual dependencies and interindividual heterogeneity. This also allowed for individual baseline adjustment. All models were estimated using Restricted Maximum Likelihood. Visual inspection of residual plots did not reveal any obvious deviations from homoscedasticity or normality. P-values were obtained using Type II Wald F tests with Kenward-Roger degrees of freedom as implemented in the R package car. Statistical significance was determined on p = 0.05, in addition confidence intervals (CI) were assessed whether they included zero or not. Results are reported as mean estimates and 95% confidence intervals. The natural log was initially calculated and analysed for HRV parameters before the above statistical analyses were carried out. A biofeedback manual cleanup process was carried out for the HRV data using the Kubios protocol.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
ACT

Funding & Sponsors
Funding source category [1] 305712 0
University
Name [1] 305712 0
University of Canberra
Address [1] 305712 0
University Dr, Bruce ACT, 2616
Country [1] 305712 0
Australia
Primary sponsor type
University
Name
University of Canberra
Address
University Drive Bruce ACT, 2616
Country
Australia
Secondary sponsor category [1] 306129 0
None
Name [1] 306129 0
Address [1] 306129 0
Country [1] 306129 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 305987 0
University of Canberra Ethics Committee
Ethics committee address [1] 305987 0
The University of Canberra, Human Ethics Committee, University Drive, Bruce ACT, 2616
Ethics committee country [1] 305987 0
Australia
Date submitted for ethics approval [1] 305987 0
01/05/2018
Approval date [1] 305987 0
01/06/2018
Ethics approval number [1] 305987 0
Project number 13-153

Summary
Brief summary
Background: The aim of this study was to explore the impact of exercise intensity on aerobic fitness and autonomic cardiac regulation (heart rate variability (HRV)) and salivary biomarkers of the stress systems (HPA-axis, cortisol; sympathetic nervous system, a-amylase) and mucosal immunity (secretory(s)-IgA), in breast cancer survivors. Methods: Seventeen participants (62 ± 8 years) were randomly assigned to; 1) high intensity interval training (HIIT; n = 6); 2) moderate-intensity, continuous aerobic training (CMIT; n = 5); or 3) a wait-list control (CON; n = 6) for a 12-week (36 session) stationary cycling intervention. Cardiorespiratory fitness (VO2peak), resting HRV and salivary biomarkers were measured at baseline 2-4 d pre-intervention and 2-4 d post the last exercise session. Results: A significant improvement (p = 0.05) was observed for VO2peak in the HIIT group; 19.3% (B = 3.98, 95%CI = [1.89 ; 4.02]) and a non-significant increase in the CMIT group; 5.6% (B = 1.96, 95%CI = [-0.11; 4.03]), compared with a 2.6% (B = -0.64, 95%CI = [-2.10; 0.82]) decrease in the CON group. Post intervention improvements in HRV markers of vagal activity (log(ln)LF/HF, LnRMSSD) and sympathetic nervous system (a-amylase waking response) occurred for individuals exhibiting outlying (> 95% CI) levels at baseline compared to general population. Conclusion: High intensity interval training improved cardiovascular fitness in breast cancer survivors and improved cardiac regulation, and sympathetic nervous system (stress) responses in some individuals. High-intensity interval training was safe and effective for breast cancer survivors to participate in with promising results as a time efficient intensity to improve physical health and stress.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 102322 0
Dr Kellie Toohey
Address 102322 0
University of Canberra
University Drive, Bruce ACT 2616
Country 102322 0
Australia
Phone 102322 0
+61411019992
Fax 102322 0
Email 102322 0
kellie.toohey@canberra.edu.au
Contact person for public queries
Name 102323 0
Dr Kellie Toohey
Address 102323 0
University of Canberra
University Drive, Bruce ACT 2616
Country 102323 0
Australia
Phone 102323 0
+61411019992
Fax 102323 0
Email 102323 0
kellie.toohey@canberra.edu.au
Contact person for scientific queries
Name 102324 0
Dr Kellie Toohey
Address 102324 0
University of Canberra
University Drive, Bruce ACT 2616
Country 102324 0
Australia
Phone 102324 0
+61411019992
Fax 102324 0
Email 102324 0
kellie.toohey@canberra.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
De-identified individual participant data of published results only.
When will data be available (start and end dates)?
Data will be available on publication to those who request it for 5 years after publication.
Available to whom?
Available on reasonable request.
Available for what types of analyses?
Data will be available to researchers only to achieve the aims in the approved proposal.
How or where can data be obtained?
Data will be available only to achieve the aims in the approved proposal and for IPD meta-analyses by emailing the primary investigator kellie.toohey@canberra.edu.au.
What supporting documents are/will be available?
No other documents available
Summary results
Have study results been published in a peer-reviewed journal?
No
Other publications
Have study results been made publicly available in another format?
No
Results – basic reporting
Results – plain English summary
Background: The aim of this study was to explore the impact of exercise intensity on aerobic fitness and autonomic cardiac regulation and salivary biomarkers of the stress systems and mucosal immunity, in breast cancer survivors. Methods: Seventeen participants (62 ± 8 years) were randomly assigned to; 1) high intensity interval training (HIIT; n = 6); 2) moderate-intensity, continuous aerobic training (CMIT; n = 5); or 3) a wait-list control (CON; n = 6) for a 12-week (36 session) stationary cycling intervention. Cardiorespiratory fitness (VO2peak), resting HRV and salivary biomarkers were measured at baseline 2-4 d pre-intervention and 2-4 d post the last exercise session. Key results: High-intensity interval training improved cardiovascular fitness in breast cancer survivors and improved cardiac regulation, and sympathetic nervous system (stress) responses in some individuals. High-intensity interval training was safe and effective for breast cancer survivors to participate in with promising results as a time-efficient intensity to improve physical health and stress.