Interval Workouts Excel In Curbing Hypertension

BARCELONA — Aerobic interval exercise training is a more effective treatment for hypertension than is moderate-intensity continuous exercise, according to a Norwegian study.

In the study, 89 patients with grade 1 or 2 hypertension who were not on medication were randomized to one of three exercise training regimens carried out three times per week for 12 weeks. The three study arms consisted of supervised aerobic interval exercise with a target intensity of 90%–95% of maximum heart rate, supervised isocaloric continuous exercise at 70% of maximum, or, as a control, standard medical advice about the importance of physical activity but no supervised training.

After 12 weeks, mean 24-hour blood pressures in the aerobic interval training group had improved from a baseline of 154/94 mm Hg to 141/87 mm Hg. Moreover, their maximal oxygen uptake (VO_2max) increased by about 15%, from 36.3 to 41.7 mL/kg per minute. Those were significantly greater improvements than noted in the moderate-intensity exercise group, which in turn did better than the unsupervised controls, Dr. Harrald E. Moelmen-Hansen reported at the annual congress of the European Society of Cardiology.

Mean 24-hour blood pressures in the moderate-intensity continuous exercise group, for example, went from 151/92 to 147/88 mm Hg, while VO_2max improved from 34.0 to 35.8 mL/kg per minute.

Mean heart rate decreased significantly in the aerobic interval group, from 73 to 69 bpm, but remained unchanged over time in the others. Similarly, nighttime blood pressures improved significantly, from 140/84 to 129/79 mm Hg, with interval training but were unchanged in the other two patient groups, according to Dr. Moelmen-Hansen of the Norwegian University of Science and Technology, Trondheim.

Endothelial function measured as flow-mediated dilation of the brachial artery increased from 6.12% to 10.07% in the high-intensity exercise group but was unaffected in the others.

HDL cholesterol increased from 54.5 to 57.2 mg/dL with aerobic interval training, and from 57.6 to 58.6 mg/dL in the continuous exercise group. It was unchanged in the unsupervised controls, Dr. Moelmen-Hansen said.