Normative aging of the respiratory system involves significant structural changes leading to a progressive decline in pulmonary function. Age-related structural changes include decreases in lung elastic recoil, airway size, respiratory muscle strength and chest wall compliance. Declines in pulmonary function are especially critical when considering the significant demands placed on the lung, airways, and respiratory musculature during conditions of dynamic exercise. Moreover, biological sex has historically not been considered within those studies designed to examine the interaction between age-related changes to the structure and function of the respiratory system and the effect on the integrated response to exercise. This presentation will first summarize changes to the respiratory system that are associated with healthy ageing. With this framework in mind, two inter-related questions will be addressed. First, what is the metabolic cost of exercise hyperpnea and how does this differ on the basis of age and sex? We have recently quantified the metabolic cost of breathing of exercise ventilations through voluntary hyperpnoea in healthy younger (23±3 y) and older (63±6 y) males and females. We found that both younger and older females have a higher cost to breathe than their male counterparts during moderate and high-intensity exercise. In addition, older individuals incur a higher cost to breathe than younger individuals for a given absolute ventilation. Second, is the pressor response during high levels of inspiratory work heightened in older adults and is there an effect of circulating ovarian hormones. Healthy, normotensive young (26±3 y) and older (64±5 y) males and females performed inspiratory pressure threshold loading to task failure. Consistent with previous reports, younger females had a lower blood pressure response to high respiratory work relative to young males. Older adults had a greater mean arterial pressure compared to young however, the sex difference was absent in older individuals. Our observations in young adults are analogous to previous work where metaboreflex responses differed by sex when limb work is performed. Likewise, we interpret the similar blood pressure response between older males and females to be related to the reduced concentration of sex hormones. Our findings point to independent effects of ageing and sex on the respiratory muscle metaboreflex responses. Collectively, our recent work speaks to the need to further understand the demands placed on the respiratory system during exercise of healthy older adults and how this may differ on the basis of sex. Understanding what constitutes ‘normal’ is especially important from a clinical perspective given that many diseases of the heart and lungs occur in older individuals.