Comparison of heart-rate and blood-pressure increases during isokinetic eccentric versus isometric exercise in older adults

The authors compared heart-rate and blood-pressure responses to typical isometric (ISO) and isokinetic (90 degrees /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.     

Firm outsourcing decisions: evidence from U.S. foreign trade zones

This article examines the operations of firms located in U.S. foreign trade subzones to study the responsiveness of outsourcing to international cost changes. I find that firms reduce their reliance on foreign inputs when dollar depreciation increases the relative price of imported inputs. The effect is pervasive across industries and is economically significant. In addition, firms that rely more heavily on imported intermediate inputs reduce their overall shipments when dollar depreciation elevates their imported, input costs. However, the magnitude of the shipments effect is economically small, suggesting that firms respond to exchange rate movements by adjusting their operations on other dimensions.