Exercise snacking to improve physical function in pre-frail older adult memory clinic patients: a 28-day pilot study

Moderate intensity intermittent lifestyle physical activity is associated with better executive function in older adults

Executive functions are among the first cognitive abilities to decline with age and age-related executive function slowing predisposes older adults to cognitive disorders and disease. Intermittent Lifestyle Physical Activity (ILPA) reflects brief, unplanned activity that occurs during routine daily activities and is operationalized as activity bouts <60s. Our understanding of short bouts of habitual physical activity and executive functions is limited. We tested the hypothesis that greater amounts of ILPA in moderate and vigorous intensity domains would be associated with better executive function in older adults. Forty older adults (26 females, 68 ± 6, >55 years; body mass index: 26.6 ± 4.3 kg/m2) completed a Trail-Making-Task and wore an activPAL 24-hr/day for 6.2 ± 1.8-days. For each intensity, total time and time spent in bouts <60 s were determined. Trail A (processing speed) and Trail B (cognitive flexibility) were completed in 25.8 ± 8.2 s and 63.2 ± 26.2 s, respectively. Non-parametric Spearman's rank correlations report that moderate ILPA (3.2 ± 3.2 min/day) and total-moderate physical activity (20.1 ± 16.0 min/day) were associated with faster Trail A (total-moderate physical activity: ρ=-0.48; moderate-ILPA: ρ = -0.50; both, p < 0.003) and Trail B time (total-moderate physical activity: ρ = 0.36; moderate-ILPA: ρ = -0.46; both, p < 0.020). However, the results show no evidence of an association with either vigorous physical activity or light physical activity (total time or ILPA bouts: all, p > 0.180). Moderate physical activity accumulated in longer bouts (>60 s) was not associated with Trail B time (p = 0.201). Therefore, more total moderate physical activity and shorter bouts (<60 s) may result in better executive functions in older adults.

Resistance Exercise Minimal Dose Strategies for Increasing Muscle Strength in the General Population: an Overview

Many individuals do not participate in resistance exercise, with perceived lack of time being a key barrier. Minimal dose strategies, which generally reduce weekly exercise volumes to less than recommended guidelines, might improve muscle strength with minimal time investment. However, minimal dose strategies and their effects on muscle strength are still unclear. Here our aims are to define and characterize minimal dose resistance exercise strategies and summarize their effects on muscle strength in individuals who are not currently engaged in resistance exercise. The minimal dose strategies overviewed were: "Weekend Warrior," single-set resistance exercise, resistance exercise "snacking," practicing the strength test, and eccentric minimal doses. "Weekend Warrior," which minimizes training frequency, is resistance exercise performed in one weekly session. Single-set resistance exercise, which minimizes set number and session duration, is one set of multiple exercises performed multiple times per week. "Snacks," which minimize exercise number and session duration, are brief bouts (few minutes) of resistance exercise performed once or more daily. Practicing the strength test, which minimizes repetition number and session duration, is one maximal repetition performed in one or more sets, multiple days per week. Eccentric minimal doses, which eliminate or minimize concentric phase muscle actions, are low weekly volumes of submaximal or maximal eccentric-only repetitions. All approaches increase muscle strength, and some approaches improve other outcomes of health and fitness. "Weekend Warrior" and single-set resistance exercise are the approaches most strongly supported by current research, while snacking and eccentric minimal doses are emerging concepts with promising results. Public health programs can promote small volumes of resistance exercise as being better for muscle strength than no resistance exercise at all.

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/.