How the time of day you exercise affects blood pressure

Examining the Circadian Timing Effects of the Hypotensive Response to Exercise

This trial will test whether exercising in the biological morning, afternoon, or evening changes 24-hour blood pressure in adults 18–39 with elevated blood pressure or stage 1 hypertension.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 30 (estimated)
• Ages: 18 Years to 39 Years
• Sex: All
• Sponsor: University of Delaware (Academic / other)
• Locations: 1 site (Newark, Delaware)
• Trial ID: NCT07049783 on ClinicalTrials.gov

What this trial studies

This fully counterbalanced, randomized crossover trial enrolls adults aged 18–39 with elevated blood pressure or stage 1 hypertension. Each participant will have dim-light melatonin onset (DLMO) measured in-lab to define their individual circadian phase, and then complete three supervised treadmill exercise sessions timed to their biological morning (DLMO+10 h), afternoon (DLMO+15 h), and evening (DLMO+20 h). Participants will wear 24-hour blood pressure monitors before and after each exercise session to capture post-exercise hypotension. The within-subject design compares the same person's blood pressure response across the three times to isolate time-of-day effects.

Who should consider this trial

Good fit: Adults 18–39 with resting blood pressure ≥120/80 mmHg and <140/90 mmHg who are not taking medications that affect blood pressure or sleep, not pregnant, and without major chronic or sleep disorders are ideal candidates.

Not a fit: People with normal blood pressure (<120/80), stage 2 or higher hypertension (≥140/90), on antihypertensive or other vascular medications, highly physically active (≥300 min/week), or with major chronic or sleep disorders are unlikely to benefit and are excluded.

Why it matters

Potential benefit: If successful, the results could help people with early high blood pressure choose the time of day to exercise that gives the biggest short-term blood-pressure lowering effect.

How similar studies have performed: Prior studies show a single exercise session can lower blood pressure for up to 24 hours, but using individualized circadian timing (DLMO) to test time-of-day effects is largely untested.

Eligibility criteria

Inclusion Criteria:

* 18-39 Years old
* Resting blood pressure greater than or equal to 120/80 mmHg or less than 140/90 mmHg

Exclusion Criteria:

* Diagnosis or history of chronic or autoimmune disease (i.e., cardiovascular, metabolic, renal, endocrine, cancer)
* Diagnosis or history of sleep disorder (i.e., obstructive sleep apnea, insomnia, restless leg syndrome)
* Alcohol or drug dependence
* Elevated risk for sleep disorders
* Elevated risk for clinical depression
* Normotensive (blood pressure less than 120/80 mmHg) or stage 2+ hypertension (blood pressure greater than or equal to 140/90 mmHg)
* Body mass index less than 18.5 or greater than 35 kg/m2
* Self-reported use of sleep medications/supplements (e.g., melatonin)
* Self-reported use of medications influencing vascular physiology (e.g., antihypertensive medications, weight loss medications)
* Highly physically active (greater than or equal to 300 minutes moderate-to-vigorous physical activity per week)
* Currently pregnant or breastfeeding
* Current tobacco use (greater than or equal to 1 cigarette in the past month)
* Nighttime or rotating shift work within the last 3 months
* Contraindications to aerobic exercise

Where this trial is running

Newark, Delaware

• University of Delaware — Newark, Delaware, United States (Recruiting)

Study contacts

• Study coordinator: Freda Patterson, PhD

Conditions Young Adults; Hypertension; Post-Exercise Hypotension; Circadian Rhythm; Young adults; Post-exercise hypotension; Circadian rhythm