Evening Smartphone Use Linked to Poorer Morning Mood in Athletes

Introduction

Adequate sleep is a critical factor for athletic performance, recovery, and overall emotional well-being. However, modern behavioral habits, particularly the use of smartphones before sleep, have raised concerns about their potential to disrupt sleep patterns and circadian rhythms. This disruption can lead to sleep debt and impaired functioning upon waking. A recent study explored these associations in a population of athletes.

The Study in Detail

The study, titled "High evening smartphone use drives sleep debt and lower morning affect in athletes," was published in Chronobiology International by Rozman et al. (2026). The research aimed to examine the connections between pre-sleep smartphone use, sleep debt, and morning affect among athletes.

The methodology involved a sample of 174 Portuguese athletes, aged 15 to 65 years. Participants completed questionnaires designed to assess their sleep patterns, habits regarding pre-sleep smartphone use, and their mood upon waking (morning affect). For analysis, participants were categorized into two groups based on their smartphone use: 'high users' (daily use) and 'low/moderate users' (use on six or fewer days per week).

Key Findings:

• Sleep Debt and Morning Affect: Greater sleep debt was found to significantly predict lower morning affect (ρ = -0.215, p = 0.004). This association was particularly pronounced among high smartphone users (ρ = -0.30, p = 0.001).
• Smartphone Use and Sleep Debt: While smartphone use itself did not significantly predict sleep debt, there was a marginal association between high smartphone use and lower morning affect.
• Mediation Analysis: A mediation analysis indicated that sleep debt did not account for the observed association between smartphone use group and next-day morning affect. This suggests a more direct link between bedtime screen exposure and immediate mood upon waking, rather than through accumulated sleep loss.

The findings suggest that frequent pre-sleep smartphone use is associated with a poorer mood upon waking, reflecting immediate sleep disruptions rather than long-term accumulated sleep loss.

Assessment

This study provides valuable insights into the impact of evening smartphone use on athletes' well-being. Its strength lies in focusing on a specific population where sleep quality directly affects performance and health. The use of both quantitative measures (sleep debt, morning affect) and categorisation of smartphone use offers a structured approach to understanding the problem. The mediation analysis is particularly insightful, as it distinguishes between the effects of immediate sleep disruption and cumulative sleep debt, suggesting that the former plays a more direct role in influencing morning mood in this context.

However, a limitation is the reliance on self-reported data for sleep patterns, smartphone use, and morning affect, which can be subject to recall bias. The definition of sleep debt as the difference between average sleep duration on work/schooldays and free days, while common, might not fully capture the complexity of an individual's sleep needs and deficits. Furthermore, the study identifies an association but does not establish causality. Other confounding factors not measured could also influence both smartphone use and morning affect.

Practical Relevance

For athletes, and indeed for the general population, these findings underscore the importance of establishing healthy pre-sleep routines. Given the prevalence of evening screen use, especially among younger demographics and those with demanding physical schedules, reducing smartphone engagement in the hours leading up to bedtime could be a simple yet effective strategy to improve mood upon waking. This is not merely about accumulating enough sleep, but also about ensuring the quality of sleep is not immediately compromised by screen exposure. Coaches, trainers, and health professionals working with athletes could integrate recommendations for limiting pre-sleep smartphone use into their guidance on recovery and performance optimization. Promoting alternative wind-down activities, such as reading a physical book, listening to calming music, or practicing mindfulness, could contribute to better emotional recovery and readiness for the day ahead.

Conclusion

The study by Rozman et al. highlights a direct association between frequent evening smartphone use and a poorer mood upon waking in athletes, independent of accumulated sleep debt. This suggests that immediate sleep disruptions caused by pre-sleep screen exposure significantly impact morning affect. Adopting healthier pre-sleep routines by reducing smartphone use could be a beneficial strategy for athletes to enhance their emotional recovery and improve readiness for daily activities and performance.