Cardiorespiratory efficiency at submaximal work in young and middle-aged women

Exercise Comes of Age: Rationale and Recommendations for a Geriatric Exercise Prescription

“…Another important consequence of age-related changes in physiologic capacity is the increased perception of effort associated with submaximal work [a lowering of the anaerobic threshold, or the approximate level at which significant dyspnea occurs (28)]. For example, between youth and middle age, an untrained man or woman may find that walking briskly results in increased blood pressure, heart rate, respiratory rate, and an earlier sense of overall and leg muscle fatigue than previously (29). This changing physical capacity has the unfortunate negative side effect of increasing the tendency to avoid stressful activity.…”