COMPARISON OF BLOOD-PRESSURE RESPONSE TO ISOKINETIC AND WEIGHT-LIFTING EXERCISE

Brachial arterial pressure, oesophageal pressure, and knee joint angle were monitored in eight untrained young men as they performed bilater al leg-press actions (simultaneous hip and knee extension and ankle pl antarflexion) against resistance. Single maximal leg-press actions on an isokinetic device evoked mean peak arterial (systolic/diastolic) pr essures of 35.4/26.2 and 34.0/23.4 kPa at lever arm velocities of 0.26 2 and 1.31 rad . s-1, respectively. The corresponding oesophageal pres sures were 13.2 and 10.4 kPa, respectively. Although the peak force wa s 30% greater, and duration of the action 3-4 times longer at 0.262 th an 1.31 rad . s-1, the arterial and oesophageal pressure responses did not differ. On a weight-lifting machine, a set of repetitions [mean ( SEM): 11 (3)] to failure at 80-90% one repetition maximum evoked peak arterial pressures of 45.5/32.8 kPa; the corresponding oesophageal pre ssure was 15.7 kPa. The peak systolic and diastolic pressures observed during weight-lifting were significantly (P < 0.05) higher than durin g isokinetic actions at both velocities, whereas oesophageal pressure was more elevated only in relation to isokinetic actions at the higher velocity. These data indicate that resisted leg-press actions cause e xtreme elevations in arterial blood pressure. The degree of voluntary effort is the major determinant of the blood pressure response, rather than the resistance mode or the type (concentric, eccentric, isometri c) of muscle action. Repetitive resistance exercise (e.g. a set of rep etitions to failure in weight-lifting) tends to produce greater pressu re elevations than isolated, single maximal effort actions.