Working adults who stay active, fit sleep better

When it comes to sleep, working adults with higher cardiorespiratory fitness (CRF) have it better, and minimizing sedentary behaviour (SB) and increasing physical activity (PA) may deliver added benefits, according to a study from Singapore.

“CRF is a comprehensive marker of exercise/physical activity patterns, heredity, age, smoking, diet, body composition, and health status… Sleep quality improvement through fitness is thought to occur because of improved parasympathetic control,” the investigators said. [Circulation 2016;134:e653-e699]

“Also, higher CRF results in better oxygen utilization and transport, [as well as help manage stress], which may in turn promote better sleep quality.” [Front Neurol 2012;3;48; Sleep Breath 2019;23:319-326; Patient Educ Couns 2013;93:146-152]

To examine the interplay of SB, moderate-to-vigorous physical activity (MVPA) and CRF with respect to sleep quality, the investigators performed a secondary data analysis on 757 working adults (average age, 35.2 years; 45.57 percent male) in Singapore.

Pittsburgh Sleep Quality Index showed that 13.2 percent of the population were sleeping poorly. These participants were more likely to be Chinese (58.8 percent), have one or more medical conditions (26.8 percent) and higher psychological distress (33.0 percent), and consume sweetened/energy (18.6 percent) or regular soft drinks (15.5 percent) when compared with those who had good sleep quality. [Int J Environ Res Public Health 2020;doi:10.3390/ijerph17041337]

In multivariable logistic regression models, higher CRF reduced the odds of having poor sleep quality (odds ratio [OR], 0.50, 95 percent confidence interval [CI], 0.28–0.91). There were no associations observed for SB and MVPA.

However, the combination of lower SB and higher MVPA conferred greater benefits for sleep quality (OR for sleeping poorly, 0.28, 95 percent CI, 0.10–0.78).

“The World Health Organization recently identified poor sleep quality as a public health problem that increases the risk of … poorer cardiovascular health, metabolic health, brain health and accidents,” the investigators said. [Sleep 2014;37:9-17]

“A recent investigation in Singapore demonstrated poor sleep quality to be associated with lower health-related quality of life in working adults. The adverse health impact and economic costs of poor sleep quality are a significant public health concern in industrialized societies … whereby the country was found to have the shortest sleep duration out of 20 countries,” they pointed out. [Int J Environ Res Public Health 2019;16:41-47; Sci Adv 2016;2:e1501705; Rand Health Q 2017;6:11]

In line with the positive findings in the current study, the investigators recommended introduction of health promotion programmes that include MVPA/exercise interventions aimed at increasing CRF.

“Further experimental studies should examine the impact of measured CRF, SB and MVPA with sleep outcomes, along with basic research focused on causal mechanisms,” they added.