Benefits beyond cardiometabolic health: the potential of frequent high intensity 'exercise snacks' to improve outcomes for those living with and beyond cancer

Exercise Snacks and Other Forms of Intermittent Physical Activity for Improving Health in Adults and Older Adults: A Scoping Review of Epidemiological, Experimental and Qualitative Studies

Exercise snacks, including other variants of brief intermittent bouts, are an emerging approach for increasing physical activity, although their operationalisation is unstandardised and their health benefits remain unclear. This scoping review aimed to explore characterisations of exercise snacks and summarise their effects on health in adults and older adults. Clinical trial registers (clinicaltrials.gov and ANZCTR) and electronic databases (PubMed, CINAHL, CENTRAL, PsycINFO) were searched from inception to 1 June 2023, for ongoing and published studies of exercise snacks. Backwards and forwards citation tracking was also conducted to identify additional eligible studies. Studies were included if they investigated exercise snacks-brief intermittent bouts of physical activity spread across the day-in adults or older adults. We included epidemiological, experimental, quasi-experimental and qualitative studies that examined the effect of exercise snacks on any health outcomes or described barriers to and enablers of these approaches. Thirty-two studies were included (7 trial registers, 1 published protocol, 3 epidemiological studies and 20 trials reported across 21 studies). Three main terms were used to describe exercise snacks: exercise snack(ing), snacktivity and vigorous intermittent lifestyle physical activity (VILPA). Participants were predominantly physically inactive but otherwise healthy adults or older adults. Exercise snacks were feasible and appeared safe. Epidemiological studies showed steep, near-linear associations of VILPA with reduced all-cause, cardiovascular and cancer mortality as well as reduced incidence of major adverse cardiovascular events and cancer. The limited trial evidence showed exercise snacks had modest effects on improving cardiorespiratory fitness, whereas effects on physical function, mood, quality of life and other health outcomes were equivocal. In conclusion, exercise snacks appear feasible and safe for adults and older adults and may have promising health benefits, but this is mostly based on findings from a limited number of small quasi-experimental studies, small randomised trials or qualitative studies. More studies are needed in individuals with chronic disease. This emerging physical activity approach may have appeal for individuals who find structured exercise unfeasible.Registration https://osf.io/qhu24/.