Clinical Trial Details
— Status: Suspended
Administrative data
| NCT number |
NCT05249205 |
| Other study ID # |
NICR4056 |
| Secondary ID |
|
| Status |
Suspended |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
February 21, 2022 |
| Est. completion date |
August 2025 |
Study information
| Verified date |
May 2024 |
| Source |
University of Stirling |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Many people do not manage to do the recommended amount of physical activity for improving
general health and wellbeing, and a common reason for this is lack of time. Sprint interval
training (SIT) has been suggested to be a time-efficient alternative to current exercise
recommendations, but most SIT protocols are not actually as time-efficient as claimed.
However, it has previously been shown that the training time commitment of common SIT
protocols can be substantially reduced while remaining effective at improving key health
markers such as aerobic fitness, insulin function and blood pressure. For example, the
reduced-exertion high-intensity interval training (REHIT) protocol consists of two 20-second
'all-out' cycle sprints within a 10-minute low-intensity exercise session. There is some
evidence that REHIT is just as effective at improving aerobic fitness with 2 exercise
sessions per week compared to 3 or 4 sessions. However, it remains unknown if improvements in
aerobic fitness are reduced if just a single REHIT session is performed each week. Therefore,
the aim of the present study is to compare improvements in aerobic fitness levels between a
control group (no training intervention), a group performing a single REHIT session per week,
and a group performing 2 REHIT sessions per week.
Description:
Up to 45 apparently healthy participants will be recruited at multiple sites. Eligible
participants will complete a fitness test to measure pre-training maximal aerobic capacity
(V̇O2max). Participants will start cycling on a stationary bike at a low intensity (30 W).
The intensity will increase by 1 W every 3 seconds until volitional exhaustion or an
inability to maintain a pedalling frequency of >60 rpm. Expired O2 and CO2 will be
continuously measured breath-by-breath using an online gas analyser. V̇O2max will be
determined as the highest value for a 15-breath rolling average of V̇O2. V̇O2max will be
accepted if at least 2 of the following criteria are met: volitional exhaustion / inability
to maintain a pedal frequency of 60 rpm, RER>1.10, a plateau in V̇O2, and/or heart rate
within 10 bpm of the age predicted maximum (220-age).
Participants will then be randomised into one of 3 groups, performing either 1 or 2 REHIT
training sessions per week, or no training intervention (control group). Randomisation will
be performed using the sealed envelope method. Participants in the control group will be
asked to maintain their regular lifestyle for 6 weeks. Participants in the training groups
will perform 6 weeks of REHIT. Each REHIT session involves 10 min of unloaded pedalling
interspersed with 2 all-out cycle sprints against a resistance equivalent to 7.5% of the
participant's body weight. Sprint duration will be 10 s in week 1, 15 s in week 2, and 20 s
in the remaining 4 weeks. The first sprint will finish at 2 min and the second sprint will
finish at 6 min. Participants will be instructed to start pedalling as fast as they can ~2-3
s before applying the sprint resistance, and to keep pedalling as fast as they can during the
sprint. Verbal encouragement will be provided. Heart rate and power output will be measured
throughout each 10-minute exercise session. The post-training V̇O2max test will be scheduled
3 days following the last training session.
