Blood Pressure and Cardiac Autonomic Adaptations to Isometric Exercise Training

Study Overview
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Brief Summary
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A randomized, sham-controlled intervention measuring the effects of isometric exercise training (IET) on blood pressure and cardiac autonomics. IET has been proven effective in a plethora of randomized trials, but very little research has employed a sham-controlled design. This researched involved the recruitment of 30 participants who completed a 4 week IET intervention, sham control of the IET intervention, or a non-intervention control period. Pre and post blood pressure and cardiac autonomic measures were acquired and analysed. The hypothesis of this trial was a significant effect of IET on blood pressure, with no such effects following the sham control or normal control interventions.

Official Title
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Blood Pressure and Cardiac Autonomic Adaptations to Isometric Exercise Training: a Randomised Sham-controlled Study

Conditions
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Hypertension

Intervention / Treatment
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* Other: Isometric exercise training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy with no significant health conditions contraindicating exercise Over 18 years of age Physically inactive Exclusion Criteria: Achieving current physical activity guidelines Abnormal resting ECG under 18

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: IET<br>Participants allocated to this arm performed 4 weeks of isometric wall squat exercise training, 3 times per week. | Other: Isometric exercise training<br>* A form of exercise involving static contraction against a wall, sustained for 2 minutes x4 sets per session. 3 sessions a week were required. The intensity was designed to achieve 95% of the participants maximum heart rate.<br>|
| Sham Comparator: Sham<br>Participants allocated to this arm performed 4 weeks of isometric wall squat training, but the training prescription was intentionally provided at an insufficient intensity to achieve any physiology stimulus. | Other: Isometric exercise training<br>* A form of exercise involving static contraction against a wall, sustained for 2 minutes x4 sets per session. 3 sessions a week were required. The intensity was designed to achieve 95% of the participants maximum heart rate.<br>|
| No Intervention: No intervention control<br>Participants allocated to this arm did not perform any exercise and were required to maintain usual daily habits. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood pressure (systolic, diastolic and mean BP) | Resting office blood pressure measured at brachial artery | At the start of the intervention (pre 4 week intervention) | 
| Blood pressure (systolic, diastolic and mean BP) | Resting office blood pressure measured at brachial artery | At the end of the intervention (post 4 weeks) | 
| Cardiac autonomics measured at HRV | LF and HF power spectral measures | At the start of the intervention (pre 4 week intervention) | 
| Cardiac autonomics measured at HRV | LF and HF power spectral measures | At the end of the intervention (post 4 weeks) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| continuous 5-minute blood pressure (systolic, diastolic and mean BP) | 5 minute mean of resting blood pressure measured beat-to-beat | At the start of the intervention (pre 4 week intervention) | 
| continuous 5-minute blood pressure (systolic, diastolic and mean BP) | 5 minute mean of resting blood pressure measured beat-to-beat | At the end of the intervention (post 4 weeks) |