The association between sympathetic nerve activity and total peripheral resistance in young men (n = 63; left panel) compared to young women (n = 37; right panel). Data are combined from a series of studies investigating blood pressure regulation in healthy adults [33–36]. Each diamond represents an individual. Measurements of nerve activity were obtained using microneurography of the peroneal nerve under the same experimental conditions . To control for fluctuations in sex hormones, women were studied only during the early follicular phase of the menstrual cycle.