AM vs PM Exercise Training

Overview

The treatment of high blood pressure, or hypertension, is multifaceted and can include pharmacological therapies (i.e., medications) and lifestyle modifications such as physical activity. Chronotherapy, which describes timing of a treatment with the body's daily rhythms, has recently been used with hypertension medications and has been shown to be effective at lowering blood pressure and reducing the risk of cardiovascular disease events. Specifically, taking medications in the evening was shown to be more effective than morning medication routines. Little information is available about the effectiveness of chronotherapy combined with exercise (i.e., planned physical activity) interventions in older adults with hypertension. The purpose of this study is to examine how exercise training performed in the morning and early evening affects blood pressure and other measures of blood vessel health in postmenopausal females with hypertension.

Full Title of Study: “Effects of AM vs. PM Exercise Training on Blood Pressure and Vascular Health in Postmenopausal Females With Hypertension”

Study Type

• Study Type: Interventional
• Study Design
  • Allocation: Randomized
  • Intervention Model: Crossover Assignment
  • Primary Purpose: Treatment
  • Masking: Single (Outcomes Assessor)
• Study Primary Completion Date: June 2026

Detailed Description

Blood pressure has an internal rhythm associated with the 24-hr clock. Nocturnal blood pressure (BP) is a key contributor to cardiovascular health and may be improved by exercise. Moreover, the time of day of the exercise may be a key factor. This study aims to evaluate the effects of morning and evening exercise training on BP and other measures of vascular function in older females with hypertension.

Interventions

• Behavioral: 6 weeks of exercise training (Pre-training)
  • handgrip and treadmill walking 4 days per week
• Behavioral: 6 weeks of exercise training (Post-training)
  • handgrip and treadmill walking 4 days per week

Arms, Groups and Cohorts

• Experimental: Morning (AM)
  • Exercise starting before 10:01 AM
• Experimental: Evening (PM)
  • Exercise starting after 3:59 PM

Clinical Trial Outcome Measures

Primary Measures

• Nocturnal systolic blood pressure (BP)
  • Time Frame: 6 weeks
  • Reduction in systolic nocturnal BP (Pre-training – Post-training)

Secondary Measures

• Endothelial function
  • Time Frame: 6 weeks
  • Increase in flow mediated dilation of the brachial artery (Post-training – Pre-training)
• Microvascular function
  • Time Frame: 6 weeks
  • Increase in rapid onset vasodilation of the popliteal artery
• Ambulatory blood pressure
  • Time Frame: 6 weeks
  • Reduction in systolic and diastolic BPs over a 24-hr period (Pre-training – Post-training)
• Arterial stiffness
  • Time Frame: 6 weeks
  • Reduction in carotid femoral pulse wave velocity (Pre-training – Post-training)

Participating in This Clinical Trial

Inclusion Criteria

• Systolic BP equal to or greater than 130 mmHg without BP medication or greater than 120 mmHg with medication and diastolic blood pressure equal to and greater than 80 mmHg – 55-80 years old – Post-menopausal female – Able to walk without assistance Exclusion Criteria:

• Habitually physically active defined as 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity aerobic physical activity per week – Overt pulmonary disease/condition as follows: chronic bronchitis, chronic obstructive pulmonary disease, emphysema, or pulmonary hypertension – Cardiometabolic disease/condition as follows: diabetes, heart failure, peripheral arterial disease, stroke, coronary artery disease, renal disease, secondary hypertension, chronic venous insufficiency or deep vein thrombosis within last 6 months – Cancer within last 5 years – Body mass index >39 kg/m2 – Current smoking or vape – Evening shift work – uncontrolled thyroid disorder – 2 or more falls in the last year – Anemia within 3 months of enrollment – Parkinson's disease – Dementia – Unstable angina – Acute pulmonary embolus or infarction – Acute myocarditis or pericarditis – Acute aortic dissection

Gender Eligibility: Female

Minimum Age: 55 Years

Maximum Age: 80 Years

Are Healthy Volunteers Accepted: No

Investigator Details

• Lead Sponsor
  • Michigan State University
• Collaborator
  • National Heart, Lung, and Blood Institute (NHLBI)
• Provider of Information About this Clinical Study
  • Principal Investigator: Katharine Currie, Assistant Professor – Michigan State University
• Overall Contact(s)
  • Jill Slade, PhD, 5178843351, jslade@msu.edu