Acute Passive Heating in Healthy Older Adults

Aging is associated with a decline in cardiovascular health, cognitive function and losses in muscle strength, with half or more of those over age 65 suffering from two or more comorbidities (e.g., heart disease, type 2 diabetes). The worldwide population of older adults is growing rapidly, with one in six people expected to be over age 65 by 2050. This will place further financial burden from chronic diseases on already stressed healthcare systems. While studies show that frequent exercise is an effective way for older adults to maintain or improve cardiovascular and metabolic health, older individuals are less physically active and do not adhere well to exercise programs, often due to physical or medical limitations. Therefore, alternative methods for older adults to get the same health benefits as exercise require further exploration. Recent work has shown a single session of passive heat therapy could be an alternative way to improve cardiovascular health and cognitive function in various populations, however, the length of time that these benefits last is yet to be explored.

Inclusion Criteria:Male or female age ≥ 55Free from cardiometabolic diseaseBody mass index of 18-35 kg/m2Receipt of a normal 12-lead ECG approved by the School Independent Medical OfficerCapacity to understand and provide their written, informed consent to participate in the study protocolExclusion Criteria:Unable to understand or cooperate with the study protocol due to learning difficulties or otherwiseAny current, or past medical (last five years), history of any cardiovascular, respiratory, cancer, renal, hepatic, gastrointestinal, haematological, lymphatic, neurological, psychiatric, or any other disease or diseases.Any regular medication for the last five years (not including acute courses of treatment of less than one month for discrete, resolved conditions).Medications that may influence physiological responses to the passive heating intervention Uncontrolled hypertension (≥ 150 mmHg systolic and/or ≥ 90 mmHg diastolic)Body mass index of > 35 kg/m2Recent long-term exposure to a hot climate (within the previous three months)Current smoker (or have stopped smoking within the previous three months)