Authors: Professor Dr. B.R. Shaalini, Raja Senthil
Abstract: Background- Essential hypertension is a major modifiable risk factor for cardiovascular disease and remains a leading cause of morbidity and mortality worldwide. Aerobic exercise is recommended as a first-line non-pharmacological intervention for blood pressure management. However, evidence comparing the effectiveness of low-intensity and high-intensity aerobic exercise on cardiovascular and functional outcomes remains limited, particularly in the Indian population. Objective- To compare the effectiveness of low-intensity and high-intensity aerobic exercise on blood pressure, functional capacity, cardiorespiratory fitness, resting heart rate, body mass index (BMI), and health-related quality of life in adults with essential hypertension. Methods- A prospective comparative pre-post study was conducted among 60 adults aged 40–65 years with essential hypertension. Participants were allocated into two groups (n = 30 each). Group A performed supervised low-intensity aerobic exercise (40–55% heart rate reserve), whereas Group B performed supervised high-intensity aerobic exercise (70–85% heart rate reserve) for 12 weeks. Outcome measures included systolic blood pressure (SBP), diastolic blood pressure (DBP), Six-Minute Walk Test (6MWT), estimated VO₂max, resting heart rate (RHR), BMI, and Short Form-36 (SF-36) quality-of-life scores. Assessments were performed at baseline and after completion of the intervention. Data were analysed using paired and independent Student's t-tests, with statistical significance set at p < 0.05. Results- Both exercise programmes produced significant improvements in all measured outcomes (p < 0.001). In the low-intensity group, mean SBP decreased from 146.8 ± 8.7 mmHg to 136.4 ± 8.1 mmHg, whereas the high-intensity group demonstrated a greater reduction from 147.3 ± 9.1 mmHg to 128.1 ± 8.8 mmHg. Functional capacity improved significantly, with the 6MWT increasing from 418.6 ± 52.3 m to 456.7 ± 52.1 m in Group A and from 421.7 ± 50.8 m to 490.8 ± 48.6 m in Group B. Significant improvements were also observed in VO₂max, resting heart rate, BMI, and all SF-36 domains, with superior outcomes in the high-intensity exercise group. Conclusion- Both low-intensity and high-intensity aerobic exercise are effective physiotherapy interventions for improving blood pressure control, functional capacity, cardiorespiratory fitness, body composition, and health-related quality of life in adults with essential hypertension. High-intensity aerobic exercise demonstrated significantly greater improvements across all outcome measures, supporting its use in appropriately screened and supervised patients.
