Which of the following is an evidence-based sleep hygiene practice?

• A. Maintain a consistent sleep schedule.
• B. Limit caffeine and screen exposure before bed.
• C. Exercise vigorously right before bed.
• D. Both maintaining a consistent sleep schedule and limiting caffeine/screen exposure before bed.

Answer: (D)

The main idea here is how to support your body's natural sleep-wake cycle and reduce things that keep you awake. Maintaining a consistent sleep schedule anchors your circadian rhythm, making it easier to fall asleep around the same time each night and wake up at the same time each morning. That consistency improves sleep onset and daytime functioning because your body learns when to expect sleep and when to be alert.

Limiting caffeine and screen exposure before bed tackles two common sources of arousal. Caffeine is a stimulant that can delay sleep onset and fragment sleep, with effects lasting hours for many people. Limiting late-day caffeine reduces this lingering stimulation. Screen exposure, especially blue light, suppresses melatonin—the hormone that helps you feel sleepy—and signals wakefulness, which can delay sleep and reduce sleep quality. Dimming screens, using blue-light filters, or avoiding devices in the hour before bed helps melatonin rise naturally and supports smoother sleep onset.

When you put both together, you create a strong, complementary approach: your body learns a reliable cue for sleep, and you remove major blockers to falling asleep and staying asleep. Exercising vigorously right before bed, by contrast, increases arousal and body temperature, which can hinder sleep, so it isn’t aligned with these evidence-based practices.