Current aspects of high-intensity interval training for older adults: a narrative review

Abstract

Negative aspects of aging include a decrease in muscle mass/strength and maximal oxygen consumption (VO2max). The most beneficial and adaptable protocol among the various exercise methods should be explored in older adults. A combination of aerobic and strength training has been recommended as an effective and required exercise program to improve both VO2max and muscle mass/strength in guidelines. Recently, high-intensity interval training (HIIT) has become a popular and time-efficient way to perform vigorous exercise effectively, potentially improving VO2max and muscle strength/power as it is rendered as a combination of aerobic and strength exercise training. It is often used by young and middle-aged people with/without chronic disease. However, the adaptation of HIIT in older adults has not been fully established yet. The effects of submaximal HIIT on metabolic, physiological, muscle adaptation, and cognitive abilities have been observed in older adults. In contrast, there is only limited evidence on sprint interval training (supramaximal), which also affects muscle strength/power and VO2max in older adults. Because some barriers remain to be overcome when implementing HIIT in older adults, the applicable protocols should be explored with stratification by age and physical function. Furthermore, data on safety, clean-up methods, adherence to participation rate, and settled intensity during unsupervised training are still lacking and should be focused on in future studies.