The Dose Response Effect of Isometric Handgrip Training Frequency on Blood Pressure: a Randomised Controlled Trial in Normotensive Individuals
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 60
- 试验地点
- 2
- 主要终点
- Resting Systolic Blood Pressure
研究概览
简要总结
It is estimated by WHO (2021) that 1.4 billion individuals across the globe have high blood pressure with only 14% of people managing these elevated levels. Simple and effective lifestyle strategies are required to help people improve their blood pressure and/or attenuate increases in blood pressure with ageing. Exercise is one possible strategy: in previous research, several different types of exercise have been shown to have effects on blood pressure (Blackwell et al., 2017). However, many individuals do not adhere to currently recommended levels of exercise (150 mins of moderate intensity exercise per week), due to a combination of the required time commitment, lack of motivation, and the associated levels of effort / exertion and discomfort (Korkiakangas et al 2009). Thus, there is a need to investigate alternative exercise interventions which will overcome these barriers but remain effective at improving blood pressure (Herrod, Lund, & Phillips, 2021).
Low intensity isometric hand grip training (IHGT) has been shown to result in large decreases in rest-ing blood pressure in younger and older age groups, in both men and women, and in individuals with normal as well as elevated baseline blood pressure (Badrov et al, 2013; Bentley et al., 2018; Millar et al., 2014). In this research, IHGT has typically involved performing 4 x 2 IHGT holds at 30% of maximal voluntary contraction, 3 times a week, over a 4-8-week intervention (Millar et al, 2014). Interestingly, there are very few studies that have investigated the effect of changing different protocol parameters on the adaptations in blood pressure, and the minimal effective dose of IHGT is unknown. One important modifiable parameter is training frequency and it is unknown whether reducing the frequency of IHGT will reduce the efficacy for improving blood pressure. Therefore, the aim of this randomised controlled trial is to compare the effect of IHGT with a frequency of 2 or 4 sessions/week on resting blood pressure.
详细描述
Data collection for this study will take place at two University sites: Swansea University in The UK and National Taiwan Normal University in Taiwan. Separate ethical approval will be sought at each site.
Participants
The primary outcome in this study will be the change in clinic measured systolic blood pressure. In a meta-analysis of 147 RCTs, a 10 mmHg decrease in SBP reduced CHD events by 22% (Law 2009). We powered this study to be able to detect a smallest worthwhile effect of 3.0 mmHg (equivalent to a CHD risk reduction of ~7%). Based on the standard deviation of repeated measures of systolic blood pressure of ~2.9 mmHg in our laboratory, a sample size of 45 participants (15 per group) will achieve 80% power to detect this difference with an alpha of 0.05. Therefore, in order to ensure equal recruitment across both study sites, we will recruit up 30 participants (10 per group) at each site. Participants will be low active men and women who do not currently meet the recommended physical activity guidelines (age range: 18-40 years).
The study protocol will be fully explained to all subjects in written and verbal form before they are asked to provide written consent. Participants will be randomised to one of three experimental groups, performing either 2 or 4 isometric handgrip training sessions per week for 4 weeks, or a no-intervention control.
Baseline Testing
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
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
- •Aged between 18 and 40 years
- •Scoring 'low' on the international physical activity questionnaire (IPAQ)
- •Apparently healthy with no indications of chronic disease according to a self-report health history questionnaire and the physical activity readiness questionnaire.
- •Resting blood pressure <140/90 mmHg during baseline assessment.
排除标准
- •Aged <18 or >40 years
- •Previously diagnosed with hypertension and/or currently taking anti-hypertensive medication.
- •Any contraindication to exercise based on responses to the self-report health-history questionnaire or the physical activity readiness questionnaire.
- •Scoring moderate or high on the international physical activity questionnaire (IPAQ).
- •Resting blood pressure >140/90 mmHg during baseline assessment.
研究组 & 干预措施
No Intervention Control
Participants allocated to this group will maintain their usual lifestyle for 4-weeks
Two Sessions/Week
Participants allocated to this group will complete 4-weeks of isometric handgrip exercise training with a frequency of two sessions/week
干预措施: Isometric Handgrip Exercise Training (IHGT) (Other)
Four Sessions/Week
Participants allocated to this group will complete 4-weeks of isometric handgrip exercise training with a frequency of four sessions/week
干预措施: Isometric Handgrip Exercise Training (IHGT) (Other)
结局指标
主要结局
Resting Systolic Blood Pressure
时间窗: 4 weeks
Resting systolic blood pressure will be measured before training commences and then 3 days after the final exercise session.
次要结局
- Resting Mean Arterial Blood Pressure(4 weeks)
- Resting Diastolic Blood Pressure(4 weeks)