High-intensity interval training (HIIT) is a form of exercise that involves short intervals of near-maximal effort—such as sprinting or stair climbing— separated by intervals of moderate-intensity exercise—such as jogging or fast walking. A study that included 68 physically inactive older adults found that those who participated in an HIIT intervention experienced greater improvement in knee muscle strength and working memory and similar improvements in blood pressure and oxygen intake as participants who performed medium-intensity continuous training. Journals of Gerontology: Series A, March 2023