The Effect of Training Frequency on Improvements in Maximal Aerobic Capacity With Reduced-exertion High-intensity Interval Training (REHIT)
试验速览
- 阶段
- 不适用
- 状态
- 暂停
- 入组人数
- 45
- 试验地点
- 5
- 主要终点
- Change in maximal aerobic capacity (VO2max)
研究概览
简要总结
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.
详细描述
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- None
盲法说明
The nature of the intervention does not allow for blinding.
入排标准
- 年龄范围
- 18 Years 至 40 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Apparently healthy
- •Sedentary or recreationally active
排除标准
- •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
结局指标
主要结局
Change in maximal aerobic capacity (VO2max)
时间窗: Pre-intervention and 3 days following completion of the intervention.
VO2max is the greatest volume of oxygen an individual can consume per minute. It is a key health marker.
次要结局
未报告次要终点
研究者
Niels Vollaard
Principal investigator
University of Stirling