Hypertension and exercise

* Reduce sodium intake to less than 2.3 grams per day. Studies have associated an 80meq/day reduction with a 5mmHg SBP and 3mmHg DBP decrease.

* Maintain adequate dietary potassium, calcium and magnesium intake. Increasing dietary potassium to 80meq/day resulted in average reductions of 8mmHg in SBP and 4mmHg in DBP.

* Stop smoking and reduce dietary fat, saturated fat and cholesterol intake.

Most, if not all, current guidelines recommend exercise as an adjunct to pharmacologic interventions for individuals with mild hypertension, including those on antihypertensive medication. A tailored exercise prescription, determined by exercise testing, can aid blood pressure reduction. Exercise test information provides some indication of risk stratification for patients with blood pressure response above the 85th percentile (Chintanadilok and Lowenthal, 2002). All hypertensive individuals who want to start an exercise program should have a resting electrocardiogram (ECG) taken. However, ACSM does not recommend an exaggerated blood pressure response to exercise as a screening test to identify individuals at high risk for developing hypertension.

Standard exercise testing methods and protocols may be used for individuals with hypertension. Graded exercise tests (GXT) can estimate the degree of blood pressure response during exercise, rate of recovery and incidence of arrhythmias during the test. When undergoing a GXT, individuals should be taking their usual medications. A resting SBP equal to or greater than 200mmHg or a DBP equal to or greater than 115mmHg is considered a contraindication to exercise testing. During the test, if SBP rises above or equals 260mmHg or DBP rises above or equals 115mmHg, the test should be terminated immediately (ACSM, 1997).

According to ACSM, 20 to 60 minutes of aerobic exercise, three to five days per week, at 50 to 85 percent of maximal oxygen uptake is appropriate for individuals with mild hypertension. However, for individuals in Stage 2 or 3 hypertension, exercise should be at 40 to 70 percent of maximal oxygen uptake after patients begin pharmacological therapy (Stewart, 2000). Resistance training is recommended as an adjunct to aerobic exercise. It should be performed independently, since research has not shown it can decrease blood pressure consistently, with the exception of circuit weight training (ACSM, 1993). This type of training should use low resistance and high repetitions (ACSM, 1997). The American Heart Association recommends mild to moderate resistance training at 30 to 60 percent of maximal effort for improving muscle strength and endurance (Stewart, 2000).

Conclusion

An abundance of evidence suggests increasing physical activity in sedentary individuals and maintaining it in active ones can significantly impact hypertension. The amount of activity required for benefit is feasible for almost everyone. Counseling by health care providers is one important, but underutilized, method of encouraging adults to engage in physical activity and exercise. Moreover, physical activity opportunities in schools and communities should be encouraged for hypertension prevention and intervention across all age groups (Lesniak and Dubbert, 2001).