Sex- and age-related blood pressure response to dynamic work with small muscle masses.

Four groups of subjects of different ages and sex (group I: 20-29 years, women; group II: 20-29 years, men; group III: 30-39 years, women; group IV: 30-39 years, men) undertook dynamic one-hand work (load range 40%-80% of maximum voluntary contraction, at 60 working cycles/min) to allow a study of cardiovascular responses as shown by the resultant changes in blood pressure and heart rate. During fatiguing dynamic one-hand work, there was a large increase in systolic and diastolic blood pressures in both sexes after a few minutes. For all load levels, the systolic blood pressure was found to be higher by about 4 kPa in men (groups II and IV) than in women (groups I and III). Other age-related differences became evident in the diastolic blood pressure changes. The values obtained for the older groups were higher than those in the two younger groups. These differences in blood pressure response are possibly due to sex-related differences in the release of catecholamines, or to age-related organic changes in the vessels.