Clinical Trial Details
— Status: Recruiting
Administrative data
| NCT number |
NCT05351177 |
| Other study ID # |
009112 |
| Secondary ID |
|
| Status |
Recruiting |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
October 1, 2021 |
| Est. completion date |
January 2023 |
Study information
| Verified date |
April 2022 |
| Source |
University of Sunderland |
| Contact |
David Archer, PhD |
| Phone |
0191 515 3381 |
| Email |
david.archer-1[@]sunderland.ac.uk |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Overweight and obesity is becoming increasingly prevalent, constituting 64% of all adults in
England, causing an incessant rise in cost to the National Health Service. Exercise and
physical activity have the potential to reduce incidence of overweight and obesity, as well
as improve obesity-related ill health. However, overweight and obese individuals are
inherently sedentary and do not meet exercise guidelines. Same-session concurrent exercise
training may be the most efficient exercise strategy to incorporate both cardiovascular- and
strength-based exercise, both of which are vital for health-related benefits. This research
project will aim to determine the feasibility of completing an 8-week concurrent exercise
training programme in overweight and obese sedentary males. This study will aim to recruit
adult males with a BMI above 25 kg.m2, who are otherwise healthy, but not regularly achieving
exercise guidelines (less than 150 minutes of physical activity and 2 strength training
sessions per week). Participants will undergo baseline and post-training testing of
cardiorespiratory fitness, strength, heart and metabolic health, as well as a series of
questionnaires and a semi-structured interview. They will then be randomised into one of two
groups (high-intensity interval training or concurrent training) to complete twice-weekly
exercise sessions for 8 weeks. The aims of this study are to evaluate the feasibility of
performing 8-weeks of either concurrent, resistance or high-intensity interval training in
overweight and obese males. This will be determined through assessment of cardiorespiratory
fitness, strength, heart health, metabolic health, enjoyment, adherence and attendance.
Description:
This study will incorporate a randomised controlled design, involving three distinct phases
for two separate groups of participants. Participants will be randomly assigned into one of
four groups via a computerised randomiser (Sealed Envelope Ltd., 2020), with a 1:1 allocation
ratio using block sizes of two. These groups will consist of a HIIT group and concurrent
training group. Three phases will be spread across 10 weeks for each participant:
- Phase 1: baseline testing for all groups (week 1)
- Phase 2: an 8-week exercise intervention for three experimental groups (weeks 2 - 9)
- Phase 3: post-intervention testing for all groups (week 10). Participants will be
provided with all of the study information and given the opportunity to ask questions
from the researchers before providing informed consent. Full pre-exercise screening in
accordance with the American College of Sports Medicine (ACSM) guidelines for exercise
testing will be conducted. All participants will be overweight or obese (BMI > 25 kg.m2)
and sedentary but will be excluded if pre-exercise screening highlights any other
cardiovascular disease risk factor.
Phase One: Baseline Testing Once included in the study, participants will be randomised into
one of two groups (HIIT or Concurrent). Both groups will perform exactly the same baseline
testing procedures over the course of two days during Week 1 of the study duration. On the
first day participants will arrive at the University of Sunderland exercise testing
laboratory having completed a 12 hr fast, having abstained from caffeine and alcohol
consumption for 24 hr and not exercised in the previous 72 hrs, and asked to consume 500 ml
of water 1 hour prior to arrival.
Fasted blood samples will then be collected. Plasma glucose, lipid profile and HbA1C
concentrations will be assessed via a fingertip capillary blood sample. Each fingertip
capillary sample will be performed using a safety lancet. Blood samples will be immediately
analysed and disposed of in clinical waste. Samples will be analysed via a CardioChek PA
portable lipid analyser, HemoCue Hb analyser and Biosen blood glucose analyser. Once
sterilised with an alcohol wipe, skin perforations will only be made on the fingertips, and
participants will be provided with adhesive dressings should they be requested. There will
then be a short break (~30 minutes) in which participants will be provided with a light
breakfast of toasted white bread (50 g) with strawberry jam (40 g), constituting a total of
75 g Carbohydrate. After consuming the breakfast participants will score their appetite via a
visual analogue scale (Flint et al., 2000). The breakfast will standardise pre-exercise
nutritional status both between- and within-participants.
Pre-exercise health screening will be completed in line with American college of sports
medicine (ACSM) and University of Sunderland guidelines. Inclusive of this screening
procedure will be anthropometric measures (height, mass, waist and hip circumference) as well
as resting heart rate (determined via a Polar heart rate monitor and wristwatch) and resting
blood pressure (via automatic sphygmomanometer). Participants will be excluded upon evidence
of any contraindications to exercise (ACSM, 2020). In addition to this, body fat will be
determined via the BodyStat 1500 bioelectrical impedance device. This will not occur if the
participant has any form of pacemaker device. Hydration status will be determined prior to
bioelectrical impedance via an Osmocheck portable analyser.
Participants will complete strength testing measures at the University of Sunderland exercise
testing gym. Each participant will complete an 8-repetition maximum (8RM) test for each of
the following exercises: barbell squat, barbell deadlift, barbell chest press, machine
shoulder press under supervision of a qualified gym instructor. The protocol will follow a
reliable and valid method set out by Taylor and Fletcher (2012). Participants will perform
familiarisation with each exercise, finding a resistance they deem 'somewhat easy' for one
repetition and practising until they demonstrate correct technique to the qualified gym
instructor. Thereafter, increasing amounts of load will be added until participants can
complete an 8th but not a 9th repetition using correct technique. If more than 8 repetitions
can be performed the load will be increased 5 - 10%, with 3 mins rest allowed between
attempts, and 5 mins between exercises. Grip strength will then be assessed in both hands via
portable dynamometer. The strength tests will be the first exercise assessments completed in
order to minimise influence of the interference effect (Laursen and Buchheit, 2019). This
will conclude day one of baseline testing, which will take 1.5 - 2 hours to complete.
On day two participants will arrive at the University of Sunderland a minimum of 24 hrs after
their first visit, having completed a 12 hr fast, no additional exercise and continued their
abstinence of caffeine and alcohol the previous 72 hrs. Participants will complete an oral
glucose tolerance test (OGTT) to assess insulin sensitivity and glucose uptake. Participants
will consume 75 g of carbohydrate in the form of a commercially available glucose solution -
a safe and standardised amount to administer (Belfiore et al., 1997). Thereafter, the
participant will remain in the laboratory for 120 mins, with fingertip blood samples taken at
rest and at 20 min intervals to determine plasma glucose concentrations. In total, the
participant will have seven fingertip blood samples. The 20 min gaps between blood samples
will be used to familiarise participants with various scales that will be used throughout the
study, including ratings of perceived exertion (RPE - Borg, 1982), the physical activity
enjoyment scale (PACES, Kendzierski & DeCarlo, 1991) and the feeling scale (Hardy & Rejeski,
1989). Participants will also complete the PRETIE-Q questionnaire for understanding
preferences and tolerances of exercise intensity (Ekkekakis, 2005). Likewise, participants
will complete a semi-structured interview with the lead researcher of ~20 minutes in
duration. Questions will focus on personal barriers to regular physical activity and previous
exercise experiences. The questions are based on previous research which has sought to
understand amounts of physical activity completed and barriers to exercise participation
(McIntosh et al., 2016; Willett et al., 2019). This interview will be recorded and
transcribed, with each participant assigned a code for the duration of the study so that all
information remains anonymous. The template for both baseline and post-intervention
interviews are included in attachments.
Participants will then complete a cardiopulmonary exercise test (CPET) in the exercise
testing laboratory. A 12-lead electrocardiograph (ECG) with the Mason-Likar electrode
placement will be taken at rest and throughout exercise. Participants will complete the CPET
on a Lode cycle ergometer, involving a 5 min warm-up at 60 W to prevent musculoskeletal
injury and a ramped workload protocol (individualised 15 - 25 W.min-1) that will terminate at
volitional exhaustion (8 - 12 mins). Respiratory gases will be collected with
breath-by-breath measurements via a metalyzer (Cortex, Metalyzer) and converted to 30 second
averages for ease of analysis. The highest volume of oxygen (VO2) value attained during the
test when converted to 30 second averages will be used as the participants VO2peak. The
anaerobic threshold (AT) will be identified as the point at which the ventilatory rate (Ve)
and volume of carbon dioxide (VCO2) break linearity with the volume of oxygen (VO2), using
the v-slope method (Wasserman, 1986) from the middle 5 of 7 breath-by-breath average. After
the CPET participants will undergo a 5-minute unloaded cool down during which cardiovascular
measures will continue to be monitored. This will conclude day two of baseline testing, with
the visit totalling ~3 hours in duration.
Participants will also undergo a standard transthoracic echocardiogram (TTE) to determine
structural cardiac adaptations. An initial assessment will be performed at the University of
Sunderland in the school of medicine, lasting no longer than 30 minutes. A second assessment
will be completed at the end of the training programme. A series of echocardiographic
parameters will be obtained, including wall thickness, ventricular ejection fraction and left
ventricular mass. The screening will be carried out by a qualified cardiac physiologist.
Participants will be immediately excluded from the study with the presence of any cardiac
abnormalities and referred to their general practitioner. The TTE may take place on either
day of testing measures, depending on availability of the cardiologist and/or echocardiogram
at the University of Sunderland. Participants will be notified prior to their arrival on
which day their TTE will take place.
In addition, throughout the baseline testing week habitual diet and physical activity levels
will be recorded. A representative 3 - 4 day period will be selected in which a diet diary
will be self-reported by all participants, with each instructed on how this should be
completed. Two weekdays as well as one weekend day will be completed as a minimum. This will
be analysed for energy intake and relative macronutrient intakes by the researchers. Habitual
physical activity levels will be assessed via ActiGraph wGT3X-BT (ActiGraph, USA) activity
monitors. Each participant will be instructed on how to correctly place the monitor around
the waist, which will be in place for 3 - 5 days across the week of baseline testing (a
minimum of one midweek, and both Saturday and Sunday). The raw accelerometer data will be
uploaded to Actilife Software (ActiGraph, USA), from which energy expenditure and time spent
in moderate to vigorous exercise will be extracted.
Phase 2: Exercise Interventions Three groups will undergo a twice-weekly, 8-week exercise
training programme. Each exercise session will be separated by a minimum of 48 hrs to aid
recovery, prevent incidence of musculoskeletal injury and standardise the programme.
HIIT Group Participants in the HIIT group will arrive at the exercise testing laboratory at
the University of Sunderland for each visit. Resting measures of heart rate and blood
pressure will be collected. The HIIT protocol will be completed on a Lode cycle ergometer,
with a 5 min warm-up at 60 W followed by a stretching period to prevent musculoskeletal
injury. The protocol will follow a modified-style HIIT design with 10 x 60 s intervals
interspersed with 60 s rest. The intensity of the HIIT intervals will be set using the delta
(Δ) method in order to create individualised workloads specific to the participant, ensuring
workloads are well matched for all individuals. This will involve setting the intensity of
exercise based on each participant's CPET results, using the workload at the AT, the VO2peak
and a percentage of the gap between these two. All participants will cycle at 80% Δ for 60 s
followed by 60 s rest, for a total of 20 minutes. Following the final HIIT interval
participants will continue cycling for 5 min at 60 W in a cooldown phase. This will
constitute a total session duration of 30 mins. All HIIT sessions will be supervised by a
member of the research team.
Concurrent Group Participants in the same-session concurrent training group will perform
training sessions that involve 50% of the HIIT and Resistance protocols. Participants will
arrive at the exercise testing laboratory and gym at the University of Sunderland for each
visit. Resting measures of heart rate and blood pressure will be collected. Participants will
complete a 5 min cycling warm-up at 60 W on a cycle ergometer followed by a stretching
period. The resistance training component will be completed first and on the same four
exercises as baseline testing in order to minimise influence of the interference effect.
However, participants will only complete 4 repetitions of their 8RM, be given 30 s rest and
then complete 1 set of 8 repetitions at 100% of their 8RM, with 60 s rest before moving on to
the next exercise. This will ensure 150 s is spent on each exercise, allowing for a total of
10-minutes on resistance exercises. Participants will then move onto the Lode cycle ergometer
to complete the HIIT aspect of their training session. They will complete 5 x 60 s intervals
at 80% Δ interspersed with 60 s rest, completing a total of 10 mins of HIIT. A 5 min cycling
cooldown on the Lode cycle ergometer at 60 W will be completed in the same manner as the
other groups. This will ensure that the concurrent training session will last 30 mins in
duration. All concurrent sessions will be supervised by a member of the research team and a
qualified gym instructor.
For all three groups participants will be fitted with Polar Bluetooth heart rate monitors for
continuous measurement throughout exercise. Five minutes after the end of the exercise
session participants will be asked to complete a session-rating of perceived exertion (CR100
Scale), the PACES enjoyment scale and the Feeling Scale. In the first, fourth and eighth
weeks, one of the training sessions will be used to collect additional data on the
physiological load across the programme. The HIIT group will have respiratory gases analysed
during their workout, the resistance group will have a post-exercise fingertip capillary
blood sample to determine lactate concentration via Lactate Pro 2 (Arkray, Japan). The
concurrent group will have both respiratory gases and lactate concentration assessed after
the resistance and HIIT aspects respectively.
Phase 3: Post-intervention Testing Post-intervention testing will be completed by all groups
and replicate all of the tests that took place across two days during baseline testing. The
only change from these tests will be that the semi-structured interview will focus on the
overall experience of the training intervention, the participant's desire to continue and the
feasibility of employing such an exercise intervention in free-living conditions. There would
not be a post-exercise semi-structured interview for any participants in the control group.
