Unilateral and Bilateral Resistance Training in Hypertension

Hypertension is associated with autonomic nervous system dysfunction, reduced muscle strength, and impaired functional capacity, all of which contribute to increased cardiovascular risk and decreased quality of life. Resistance training is recommended as a non-pharmacological intervention for hypertension; however, it remains unclear whether unilateral and bilateral resistance training produce different physiological adaptations, particularly regarding cardiac autonomic function.

This randomized controlled trial aims to compare the effects of unilateral and bilateral resistance training on heart rate variability (HRV), muscle strength, and functional capacity in adults with hypertension. Eligible participants aged 40-75 years with a confirmed diagnosis of hypertension will be randomly allocated to one of three groups: a unilateral resistance training group, a bilateral resistance training group, or a control group. Randomization will be performed using a computer-generated block randomization procedure with sex stratification to ensure balanced group allocation.

Participants in the two intervention groups will complete a supervised 12-week resistance training program, performed twice weekly at an intensity of 60-70% of one-repetition maximum (1RM). The unilateral training group will perform exercises using one limb at a time, whereas the bilateral training group will perform the same exercises simultaneously with both limbs. The control group will receive no structured exercise intervention during the study period but will receive general information regarding the benefits of physical activity.

Assessments will be conducted at baseline and after the 12-week intervention. The primary outcome will be heart rate variability measured using a Polar H10 heart rate sensor and Elite HRV software. Secondary outcomes will include peripheral muscle strength assessed by one-repetition maximum testing, functional capacity assessed using the Six-Minute Walk Test and the Glittre Activities of Daily Living Test, and blood pressure measured using a sphygmomanometer.

The findings of this study are expected to provide evidence regarding the optimal resistance training strategy for improving autonomic function and physical performance in individuals with hypertension, thereby supporting the development of safer and more individualized exercise prescriptions.