Abstract

Purpose: Determine if the previously reported exaggerated systolic blood pressure response to daily activity and moderate exercise amongst hypertensive adults could be accounted for by differences in fitness. Methods: 30 normotensives adults (15 low fitness control (LFC) and 15 high fitness control (HFC)) and 15 unmedicated adults with ambulatory hypertension (HTN) participated in this study. Participants completed 24-hour ambulatory blood pressure monitoring (ABPM). Lactate Threshold (LT) and estimated ����̇O2max were determined for each participant. A week later, blood pressure was measured while participants completed 5-minute bouts of treadmill exercise at fixed absolute intensities (2.5 mph 0% and 12% grade) and intensities relative to their own LT (80% and 120% LT). Indices of vascular function, pulse wave velocity (PWV) and passive leg movement (PLM)-induced hyperemia were also measured. Results: Hypertensive adults exhibited lower LT, ����̇O2max, and vascular function than HFC (P< 0.05), but not LFC (P>0.05). They also exhibited a greater metabolic strain (e.g., lactate, respiratory exchange ratio (RER)) and a greater increase in systolic blood pressure (SBP) during absolute intensity exercise (2.5 mph, 12% grade) than HFC (P< 0.05), but not LFC (P>0.05). When performing exercise at intensities relative to LT, no differences in the change from resting SBP (ΔXSBP) were observed between groups (P>0.05). After statistically controlling for resting SBP, LT was significantly related ΔXSBP when walking 2.5 mph at 12% grade (r=-0.370, P=0.016) and daytime SBP (r=-0.489, P=0.001). Conclusion: Low fitness levels contribute to elevated SBP during moderate intensity exercise and activities of daily living (ADL) in hypertension. When controlling for fitness level, adults with hypertension do not exhibit an exaggerated SBP response to exercise. Interventions to improve fitness level may reduce blood pressure during ADL and moderate exercise.

Degree

MS

College and Department

Life Sciences; Exercise Sciences

Rights

https://lib.byu.edu/about/copyright/

Date Submitted

2025-06-18

Document Type

Thesis

Keywords

blood pressure, exercise, hypertension, fitness, lactate threshold

Language

english

Included in

Life Sciences Commons

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