BACKGROUND: Evidence exists for seasonal and/or weekday-weekend variations in physical activity (PA) in some geographies. However, there is little evidence that these inconsistent patterns, contrasted with more consistent PA, negatively impact health outcomes over time – beyond total or average PA levels (e.g. if PA guidelines are met, regardless of patterns to get there). Does consistent PA throughout the year and through each week lead to better health outcomes, compared to the same total PA inconsistently performed? Further, there is no research at all in this regard with respect to sedentary behaviour (SED) patterns.

RESEARCH QUESTIONS: This research will investigate how seasonal and within-week variations in physical activity and sedentary behaviour affect cardio-metabolic health outcomes in adults. The objectives are:

1. To describe seasonal (winter, spring, summer, fall) variations in PA and SED;
2. To describe daily variations in PA and SED (e.g. active daily vs. “weekend warrior”); and
3. To investigate how different patterns of PA and SED are associated with weight status, adiposity, blood pressure, and blood lipids and glucose levels.

METHODS: Participants (n=200) aged 20- 65 will visit the U of R Physical Activity Epidemiology Lab 4 times in 1 year (once per season). At each visit they will have measures taken (anthropometric, blood pressure, body composition, finger prick blood test) and complete a demographics, health and lifestyle questionnaire. Participants will also wear an ActiGraph accelerometer on a belt at their hip for seven days to measure their PA and SED levels. Archived weather data will be obtained from Environment Canada.

SIGNIFICANCE: The results of this research will provide much needed Canadian data enhancing our understanding of PA and SED patterns, and associations with health outcomes. The summer-winter climate extremes in Saskatchewan may be more likely to produce inconsistent PA patterns compared to more moderate climates. The results may therefore provide insight into the higher rates of obesity in Saskatchewan, allowing for better targeted interventions to increase PA, reduce SED, and ultimately reduce obesity and its health consequences.