The findings by researchers at Johns Hopkins call into question the effectiveness of national guidelines on exercise for lowering blood pressure in older people.

Current guidelines from the American College of Sports Medicine recommend 30- to 45-minute periods of combined aerobic exercise and moderate weightlifting, three to five times per week, with an expected reduction in blood pressure of 8 millimeters to 10 millimeters of mercury (mm/Hg).

For a six-month period, the Hopkins researchers analysed blood pressure in 104 men and women ages 55 to 75. Half were randomly placed in a standardised moderate exercise program while the rest maintained their usual physical routine and diet.

Using ultrasound imaging, the researchers also examined "artery stiffness” in a subset of 82 study participants by gauging the velocity of pulse waves generated by heart contractions.

At the end of the SHAPE study, exercisers showed significant improvements in overall fitness, as measured by their performance on a treadmill and by how much weight they could lift. Improvements were also seen in body composition, such as increased lean muscle mass and reduced fat, especially fat surrounding the waist and inside the abdominal cavity.

However, reductions in blood pressure were mixed, with both program exercisers and the non-exercising group lowering systolic blood pressure measurements by 5.3 mm/Hg and 4.5 mm/Hg. Measures of artery stiffness did not improve significantly in either exercisers or non-exercisers.

Alternatively, the authors suggest, older persons may need to get started sooner on medications to immediately bring blood pressure under control, rather than relying strictly on exercise, although a comparison of exercise to drugs requires further study.

MEDICA.de; Source: Johns Hopkins Medical Institutions