The links between commuting time and sleep quality: a trend in modern urban centers

Recent decades have been marked by significant urban spread in countries around the world and the growth in the number of large urban centers, with the majority of the global population now living in cities. Moreover, forecasts indicate that this pattern will continue in the following decades. The daily routine in a large city presents its own array of challenges to its inhabitants, frequently defining lifestyle and habits, and affecting quality of life.

One of the most important practices dictating the routine of the urban population is commuting, defined as recurring travel between home and the place of work or study. In metropolises and conurbations, commuting times may vary greatly, with larger distances frequently being traveled by middle- and lower-class individuals who cannot afford to live in central neighborhoods.

The circumstances of commuting (and especially the time invested in it) have become a focus of concern in several studies mapping the quality of life of the general population, although in much of the literature time spent commuting is not measured separately from the resting or nonworking period. As stated by Ikeda and colleagues,¹ the European Union² defines the daily resting period as the time spent away from the workplace; this is then divided among the many activities performed during this period, such as preparing and eating meals, exercising, studying, taking care of the family, and sleeping. It is also recommended by the European Union that this period should last a minimum of 11 hours. With longer commuting times, the proportion of this period available for nonworking activities is reduced, with sleep often being the most affected, although other activities related to health, such as preparing meals (with greater reliance on ready-made and/or takeaway options) and undertaking exercise, are also impacted. Commuting time, which should not be considered part of the resting period as it has a direct link to working is often associated with stress and can preclude other rest activities that are relevant in respect to health and general quality of life.

Research by Christian³ showed that longer commuting times were associated with a reduction in sleep duration of between 28% and 35%. Longer commutes may also have an active role in decreasing sleep quality, with a significant association between insomnia symptoms and longer commuting times being detected.⁴ In another study, commuting time was found to be the second waking activity most exchanged for sleep, only behind work, with short sleepers reporting to be traveling more and starting traveling earlier and finishing later than normal sleepers.⁵ A longer commuting time has also been linked to a poorer self-perception of overall health,⁶ while a positive relationship between the duration of the daily resting period and sleep quality has been identified, although this evidence was not specifically connected to commuting times.¹

The quality of commuting conditions must be also considered. Commuting by public transport has been associated with increased stress and worsened mood compared with cycling or walking to work, which tend to be related to a better mood and lower reported levels of stress.⁷ Vargas-Garrido and colleagues⁸ demonstrated that poor sleep was associated with an increased chance of commuting accidents and suggested that there may even be a bidirectional relationship, although there was no evidence to confirm this.

At present, little action has been taken to solve the problem of increased commute times caused by the growth of cities. Possible solutions could include improvements in public transport systems, de-centralization of commercial and economic centers, thus reducing the necessity of longer commuting times, and an increase in working from home, which became more popular during the coronavirus disease 2019 (COVID-19) pandemic. However, these solutions are dependent on large-scale changes in urban structure, which would require significant action being taken by governments. In the case of home working, there needs to be a suitable home environment, and this would largely depend on the personal circumstances of the worker, although companies could take measures to promote home working.

Given the rise of the problem of increasing commuting, there is a pressing need for further studies on this subject, including initiatives that use validated self-reported sleep measures or objective measures of sleep, such as actigraphy, to better understand its impact on the sleep quality of workers. Properly characterizing the extent to which sleep is being impaired due to commuting is important in order to improve the quality of life of populations and should be a priority for our urban areas in the 21st century.

DISCLOSURE STATEMENT

The authors’ studies are supported by grants from the Associacão Fundo de Incentivo à Pesquisa (AFIP). G.L.F. is supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior–Brazil (CAPES; Finance Code 001) and the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq #141445/2021-1). M.L.A. and S.T. are Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) fellowship recipients. M.L.A. received financial support from Aché Laboratórios Farmacêuticos but ensures this was in no way connected to this study. The authors report no conflicts of interest.