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The Galway Sea Swimmers Study

Not Applicable
Suspended
Conditions
Hypertension
Cardiovascular Diseases
Interventions
Other: No cold-water sea swimming
Other: Cold-water sea swimming
Registration Number
NCT04290637
Lead Sponsor
National University of Ireland, Galway, Ireland
Brief Summary

Cardiovascular disease (CVD) is the leading cause of death worldwide. Hypertension is a well-established risk factor for the development of CVD. Lifestyle modifications, including exercise, remain the cornerstone of blood pressure (BP)-lowering strategy. Swimming has long been a popular recreational activity for exercise, and is recently gaining widespread recognition as an effective option in maintaining and improving cardiovascular health. Previous studies that involved pool swimming as an intervention (versus no pool swimming) demonstrated favorable benefits of the former on BP reduction. However, no studies to date have specifically investigated the effect of cold-water sea swimming on BP. Indeed, the naturally lower water temperature in the sea may engender a 'cold water immersion' experience in sea swimmers with subsequent stress physiology, which have been shown to exert unique effects on cardiovascular hemodynamics. This study primarily aims to determine the impact of cold-water sea swimming on BP in a group of habitual sea swimmers in Galway who will be randomly assigned to either continue or stop swimming for 4-6 weeks. Other objective and subjective health benefits to sea swimming will also be explored in this study. Given the ubiquitous nature of this activity in the Irish general public, particularly in Galway, this study has potential from a public health perspective, and would add to the literature base pertaining to the benefits of sea swimming on cardiovascular health.

Detailed Description

Consenting participants will be randomly assigned, 1:1, to either continuation of sea swimming or discontinuation of sea swimming for 4-6 weeks, stratified by the type of swimmer (those who purely immerse in the water for a brief period of time versus those who actually swim \[i.e., exercise\] in the water) and use of blood pressure medication at the time of study commencement (yes or no), using a block size of four to maintain balance between intervention arms. In line with previous studies that assessed the impact of swimming intervention on BP, participants randomized to the swimming arm should pursue sea swimming 2 or more days/week.

Recruitment & Eligibility

Status
SUSPENDED
Sex
All
Target Recruitment
150
Inclusion Criteria
  • habitual swimmers (i.e., sea swimming at least 2 times/week for the past year)
  • 18 years of age or older
  • able to provide informed consent
Exclusion Criteria
  • underlying cardiac (e.g., self-reported heart failure) or pulmonary diseases (e.g., self-reported chronic obstructive pulmonary disease)
  • recent orthopedic procedures (e.g., joint replacement therapy)
  • severe disabling comorbidity
  • recent arm (both arms) or chest wall injury
  • pregnant or breast feeding

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
No sea swimmingNo cold-water sea swimmingStop sea swimming for 4-6 weeks
Sea swimmingCold-water sea swimmingContinue sea swimming for 4-6 weeks
Primary Outcome Measures
NameTimeMethod
Change in mean systolic blood pressureMeasured at baseline and again at 6 weeks

Systolic blood pressure recorded using a 24-hour ambulatory blood pressure monitor

Secondary Outcome Measures
NameTimeMethod
Change in Pulse Wave VelocityMeasured at baseline and 6 weeks

Pulse wave velocity measured using Complior Device

Change in Augmentation indexMeasured at baseline and 6 weeks

Augmentation index measured using Complior device

Change in Heart rate variabilityMeasured at baseline and 6 weeks

Measured using 24-hour ambulatory blood pressure monitor

Change in Health-related quality of lifeAdministered at baseline and 6 weeks

Measure using EQ-VAS (visual analog scale) instrument. Values between 0 (worst imaginable health) and 100 (best imaginable health)

Change in mean diastolic blood pressureMeasured at baseline and again at 6 weeks

Diastolic blood pressure recorded using a 24-hour ambulatory blood pressure monitor

Trial Locations

Locations (1)

Croi Heart and Stroke Centre

🇮🇪

Galway, Ireland

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