The Effect of Training Frequency on Improvements in VO2max With REHIT

General Health Clinical Trial

Official title:

The Effect of Training Frequency on Improvements in Maximal Aerobic Capacity With Reduced-exertion High-intensity Interval Training (REHIT)

Clinical Trial Details — Status: Suspended

Administrative data

• NCT number: NCT05249205
• Other study ID #: NICR4056
• Status: Suspended
• Phase: N/A
• 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
• 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.

Recruitment information / eligibility

• Status: Suspended
• Enrollment: 45
• Est. completion date: August 2025
• Est. primary completion date: August 2025
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 40 Years

Eligibility

Inclusion Criteria:

• Apparently healthy

• Sedentary or recreationally active

Exclusion Criteria:

• Classified as highly physically active on the International Physical Activity Questionnaire (IPAQ)

• Answering 'Yes' to any of the questions of a standard Physical Activity Readiness Questionnaire (PAR-Q)

• Resting heart rate >100 bpm

• Resting blood pressure > 140/90 mm Hg

• BMI > 35 kg/m2

• Testing positive for Covid-19

• Pregnant women

Related Conditions & MeSH terms

• General Health

Intervention

Behavioral:
• REHIT1
This intervention involves a single REHIT exercise session per week. REHIT involves 10 minutes of unloaded cycling on a stationary bike interspersed with two 20-second 'all-out' cycle sprints against a resistance equivalent to 7.5% of body mass.
• REHIT2
This intervention is the same as that for the REHIT1 intervention, but with 2 sessions per week instead of 1.

Locations

Country	Name	City	State
United Kingdom	University of Stirling	Stirling	Stirlingshire
United Kingdom	Swansea University	Swansea
United Kingdom	University of Worcester	Worcester	Worcestershire

Sponsors (3)

Lead Sponsor	Collaborator
University of Stirling	Swansea University, University of Worcester

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in maximal aerobic capacity (VO2max)	VO2max is the greatest volume of oxygen an individual can consume per minute. It is a key health marker.	Pre-intervention and 3 days following completion of the intervention.