You brush your teeth, put on pajamas, and get into bed. It feels like a routine. But within that routine—and in the hours leading up to it—there are habits you may not realize are working against your sleep. Some are obvious, like scrolling through your phone. Others are subtle: a glass of wine, a late afternoon coffee, a nap that runs too long. This article examines what the research actually says about common nighttime habits and how they affect your sleep quality.

Your nighttime routine is not just what you do in the last five minutes before bed. It is everything you do from mid-afternoon onward.

A 2024 study published in the Journal of Behavioral Medicine tracked 74 undergraduate students over 14 consecutive days, using objective sleep measures and linear mixed modeling to assess how 32 different sleep hygiene behaviors related to sleep outcomes. The findings were nuanced. Later bedtimes and earlier wake-times were associated with better sleep at both between-person and within-person levels. More frequent napping was linked to increased night awakenings and greater time spent awake after sleep onset. Falling asleep with music or the TV on, eating too much before bed, and alcohol use were each associated with increased awakenings. Having an unpleasant conversation before bed and sleeping in a poorly ventilated room were linked to greater time spent awake during the night [citation:1].

Habit 1: Using Screens to Fall Asleep

The research on screen use before bed is consistent and damning. A 2023 study of Brazilian adults found that screen time before bed was linearly associated with shorter sleep duration, longer sleep latency, and more nocturnal awakenings. The highest sleep duration and lowest sleep latency were observed in participants who used no electronic devices with illuminated screens before bed [citation:7].

A meta-analytic review of adolescent sleep found that phone, computer, and internet use were associated with delayed bedtimes, while computer use and evening light were linked to decreased total sleep [citation:3]. The mechanism is twofold: blue light suppresses melatonin production, and the cognitive engagement of scrolling or gaming increases mental arousal.

If you use your phone as a sleep aid—scrolling until your eyes finally close—you are training your brain to associate your bed with stimulation, not rest.

Habit 2: Drinking Alcohol as a Nightcap

Alcohol is widely believed to help with sleep because it makes you feel drowsy. The research tells a different story. The 2024 Journal of Behavioral Medicine study found that alcohol use was associated with increased night awakenings [citation:1]. A 2023 Brazilian study found that evening alcohol consumption was associated with lower nocturnal awakenings in their sample, but the authors noted this was a between-persons effect—meaning habitual drinkers may develop tolerance rather than that alcohol improves sleep [citation:7].

A 2026 narrative review in Nutrients concluded bluntly: although alcohol may reduce sleep onset latency, it disrupts sleep architecture, suppresses REM sleep, increases fragmentation, and impairs breathing during sleep—particularly in the second half of the night. Alcohol should not be considered a sleep aid.

Habit 3: Napping Too Long or Too Late

Napping is a double-edged sword. A short nap can be restorative, but the research shows that napping frequency and duration matter. The 2024 study found that more frequent napping was associated with increased night awakenings and greater time spent awake after sleep onset [citation:1]. A 2023 Brazilian study found that napping for more than 30 minutes was associated with 46% higher odds of self-perceived poor sleep quality [citation:7].

The practical guidance: if you nap, keep it under 30 minutes and avoid napping after mid-afternoon. Longer or later naps reduce your homeostatic sleep drive—the biological pressure that builds throughout the day and helps you fall asleep at night.

Habit 4: Eating a Large Meal Before Bed

The 2024 study found that eating too much food before bed was associated with increased night awakenings [citation:1]. A 2023 Brazilian study found that having dinner as the largest meal was associated with 73% higher odds of poor sleep quality [citation:7].

Digestion is metabolically active. A large meal close to bedtime forces your body to work when it should be resting, and lying down shortly after eating can worsen acid reflux. If you need something before bed, a light snack is a better choice than a full meal.

Habit 5: Having Stressful Conversations at Night

This habit is less obvious than screens or alcohol, but the research is clear. The 2024 study found that having an unpleasant conversation before bed was associated with greater time spent awake after sleep onset [citation:1]. The mechanism is cognitive arousal: conflict activates the stress response, increases cortisol, and makes it harder for the brain to disengage from waking-mode processing.

If a difficult conversation needs to happen, schedule it earlier in the evening—or better yet, earlier in the day. Give yourself a buffer of at least an hour of calm before bed.

Habit 6: Sleeping in a Poorly Ventilated Room

The 2024 study found that sleeping in a poorly ventilated environment was associated with greater time spent awake after sleep onset [citation:1]. This aligns with the growing body of research on bedroom air quality. A 2023 observational study found that high CO2 levels—which accumulate in closed bedrooms without ventilation—were linked to a 4.0% reduction in sleep efficiency.

Ventilation matters. A slightly open window, a ceiling fan, or a mechanical ventilation system can reduce CO2 buildup and improve sleep continuity.

What Actually Helps

Not all nighttime habits are harmful. The research also identifies behaviors that support sleep. A 2024 systematic review and network meta-analysis of randomized controlled trials found that resistance training was the most effective non-pharmacological intervention for improving sleep quality in non-elderly individuals [citation:14]. A 2023 Brazilian study found that morning physical exercise decreased the odds of poor sleep quality by 39% [citation:7].

A 2020 randomized controlled trial found that both slow breathing exercises and music listening before bed increased immediate heart rate variability, suggesting reduced physiological arousal [citation:12]. A 2022 study found that progressive muscle relaxation before a nap increased slow-wave sleep by approximately 10 minutes—equivalent to 125% more restorative sleep [citation:18].

The takeaway: what you do in the hours before bed matters. Some habits sabotage sleep. Others support it. The choice is yours—and the research tells you which is which.

References

Bartel, K. A., et al. (2015). Protective and risk factors for adolescent sleep: A meta-analytic review. Sleep Medicine Reviews, 21, 72–85. https://doi.org/10.1016/j.smrv.2014.08.002

Castro-Santos, L., et al. (2023). Sleep-promoting and sleep-disturbing practices in Brazilian adults. Sleep Medicine: X, 6, 100088.

Hirohama, K., et al. (2024). The effects of nonpharmacological sleep hygiene on sleep quality in nonelderly individuals: A systematic review and network meta-analysis of randomized controlled trials. PLoS ONE, 19(6), e0301616. https://doi.org/10.1371/journal.pone.0301616

Kuula, L., et al. (2020). The effects of presleep slow breathing and music listening on polysomnographic sleep measures—a pilot trial. Scientific Reports, 10(1), 7427. https://doi.org/10.1038/s41598-020-64218-7

McAlpine, T., et al. (2024). Assessing the daily association of sleep hygiene behaviours with sleep: A between and within persons approach. Journal of Behavioral Medicine, 47(2), 255–270. https://doi.org/10.1007/s10865-023-00448-0

Simon, K. C., et al. (2022). Progressive muscle relaxation increases slow-wave sleep during a daytime nap. Journal of Sleep Research, 31(5), e13574. https://doi.org/10.1111/jsr.13574

Frequently Asked Questions

Does using my phone before bed really affect my sleep?

Yes. Research shows that screen time before bed is linearly associated with shorter sleep duration, longer time to fall asleep, and more night awakenings. The highest sleep duration and lowest sleep latency were observed in participants who used no illuminated screens before bed. The effect comes from both blue light suppressing melatonin and the mental arousal of engaging content.

Is it bad to drink alcohol before bed?

While alcohol may make you feel drowsy and help you fall asleep faster, research shows it disrupts sleep architecture. It suppresses REM sleep, increases fragmentation, and impairs breathing during sleep—especially in the second half of the night. Alcohol should not be used as a sleep aid.

How long should a nap be to avoid affecting nighttime sleep?

Keep naps under 30 minutes and avoid napping after mid-afternoon. Research shows that napping for more than 30 minutes is associated with 46% higher odds of self-perceived poor sleep quality. Longer naps reduce the sleep pressure that helps you fall asleep at night.

Can stressful conversations really affect my sleep?

Yes. A 2024 study found that having an unpleasant conversation before bed was associated with greater time spent awake after sleep onset. Conflict activates the stress response and increases cognitive arousal, making it harder for the brain to disengage from waking-mode processing. Schedule difficult conversations earlier in the day when possible.