The authors compared heart-rate and blood-pressure responses to typical isometric (ISO) and isokinetic (90°/s) eccentric (ECC) resistance-training protocols in older adults. Twenty healthy older adults (74 ± 5 years old) performed randomly ordered ISO and isokinetic ECC exercise (3 sets of 10 repetitions) at a target intensity of 100% of their peak ISO torque value. Heart rate and systolic (SBP) and diastolic (DBP) blood pressures were recorded continuously, and mean arterial pressure (MAP) and rate-pressure product (RPP) were calculated. ECC peak torque (139 ± 33 N · m) was significantly greater than ISO peak torque (115 ± 26 N · m; p < .001). All variables increased significantly (p < .001) during both ISO and ECC exercise. Changes in SBP, DBP, MAP, and RPP were significantly greater during ISO exercise than during ECC exercise (p < .001). Clinically, an isokinetic ECC exercise program enables older adults to work at the same torque output with less cardiovascular stress than ISO exercise.
The authors are with the School of Physical Therapy, University of Western Ontario, London, ONT, Canada N6G 1H1.