September 2011 Issue

Exercise Amounts Affect Blood Pressure — Changes in Older Adults
By Joe Cannon, MS, CSCS, NSCA-CPT
Today’s Dietitian
Vol. 13 No. 9 P. 88

While there’s little dispute that seniors should make exercise part of their daily routine, those with hypertension may wonder whether exercise—specifically strength training—can safely be part of their regimen. And if it’s deemed permissible by their physician, how much exercise might be best for someone with hypertension?

A recent study sought to determine how different amounts (volume) of resistance exercise might impact blood pressure in hypertensive older adults.1 Remember that exercise volume is determined by the equation: weight lifted X repetitions performed X sets performed.

The study consisted of 16 men and women with an average age of 68. Individuals taking hypertensive medications that might influence heart rate, such as beta blockers, were excluded from the study. Those taking medications that didn’t impact heart rate were allowed to participate.

The resistance protocol consisted of a 10-station circuit training program that included the following exercises: leg press, bench press, biceps curl, leg extension, lat pull down, triceps extension, peck fly, leg curl, seated row, and dumbbell lateral shoulder raise. An intensity of 40% of one repetition maximum (RM), or the amount of weight you can lift once, was used on each station in the circuit. The goal was to reach 20 repetitions on each station. The study consisted of the following three groups:

• Control group (40 minutes resting in a chair);

• Exercise group 1 (20 minutes of resistance exercise with one circuit completed); and

• Exercise group 2 (40 minutes of resistance exercise with two circuits completed).

Results
Each subject was randomized to a group, and all subjects took part in a different group over three sessions. All exercise sessions were separated by seven days to allow for the normalization of blood pressure between treatments. At 20 minutes before exercise, blood pressure was taken every five minutes. After each treatment and after a five-minute rest, blood pressure was measured every five minutes for the next 60 minutes. After this, blood pressure was measured every 15 to 20 minutes for the next 24 hours using an ambulatory blood pressure monitoring device.

After the study, researchers observed that systolic and diastolic blood pressures decreased beginning 60 minutes after exercise in both exercise treatments compared with controls. In exercise group 1, systolic and diastolic blood pressure were reduced by 8 mm Hg and 6 mm Hg, respectively. In exercise group 2, the reduction was 10 mm Hg and 4 mm Hg for systolic and diastolic blood pressure, respectively. Mean blood pressure 24 hours postexercise was lowest in exercise group 2, which received the most exercise.

The authors noted that the reduction in blood pressure 60 minutes postexercise is similar to previous observations in middle-aged women on hypertensive medications who performed three sets of 20 repetitions of six exercises.2 This study appears to be the first to look at exercise volume in hypertensive older adults. Circuit training is already mentioned in the American College of Sports Medicine guidelines as a useful mode of exercise for those with hypertension.

More studies need to be done to confirm these results, but if they’re upheld, those working with hypertensive older adults should also consider exercise volume to maximize physical activity’s postexercise hypotensive effects.

— Joe Cannon, MS, CSCS, NSCA-CPT, is a personal trainer, exercise physiologist, and health educator in the Philadelphia suburbs.

 

References
1. Scher LM, Ferriolli E, Moriguti JC, Scher K, Lima NK. The effect of different volumes of acute resistance exercise on elderly individuals with treated hypertension. J Strength Cond Res. 2011;25(4):1016-1023.

2. Melo CM, Alencar Filho AC, Tinucci T, Mion D Jr, Forjaz CL. Postexercise hypotension induced by low intensity resistance exercise in hypertensive women receiving captopril. Blood Press Monit. 2006;11(4):183-189.