Valerie Carson, a University of Alberta professor in the faculty of kinesiology, sport, and recreation, led a study on the negative effects of sedentary behaviour and its relationship with sleep and physical activity.
Sedentary behaviour occurs when a person is awake, when they are engaged in low energy expenditure, and when they are either sitting, lying down, or reclining.
“Once those three things are met, it’s considered sedentary time,” Carson said. “If someone was sitting and doing an exercise bike that wouldn’t be sedentary time, [sedentary behaviour] encompasses low movement while awake in [the previously mentioned] postures.”
It is important to acknowledge the risks associated with sedentary behaviour, especially when it is habitual for many. Carson emphasized that sedentary behaviour during the day is linked with high risk of mortality, chronic diseases, Type 2 diabetes, and several cancers. On top of physical effects, sedentary behaviour can also affect mental health.
“Having lower sedentary behaviour is thought to improve our cognition, our quality of life, and our physical functions.”
Carson explained how sleep plays an important role in helping regulate the amount of time in a day is spent in sedentary behaviour. During the day, we are either active, sleeping, or sedentary. These three behaviours interact with each other and make up an entire 24-hour period. Carson gave an example that if someone stays up late, they’ll be feeling too tired the next day to do physical activity.
Our health is impacted depending on the interactions and the amount of time we get in those behaviours, said Carson.
In 2020, the Canadian Society for Exercise Physiology released updated guidelines on movement behaviours in adults, including the amount of hours for each behaviour. For sleep, it is recommended to be getting seven to nine hours consistently. For physical activity, it is recommended to get several hours of light physical activity daily. Regarding sedentary time, it is recommended to get no more than eight hours, and no more than three hours of recreational screen time.
When it comes to screen use, it’s important to limit screen time, especially before bedtime. Carson explained that using screens before bed can negatively affect the regulation of hormones, as the brain starts to think it’s not actually time to sleep. This can impact the quality of sleep during the night, which can lead to increased time in sedentary behaviour the next day.
“It is important to use [screens] in moderation and take breaks … I think unplugging once in a while can be really beneficial for our mental and physical health.”
Carson concluded that future research on this topic will be focused on trying to understand the prevalence of sedentary behaviour in Canada’s population.
“At a population level, we need to understand [how to] support and promote healthy movement patterns. Trying to figure out how we can make our population move more, sit less, and sleep well [will hopefully lead to] better health and less healthcare costs.”