Split Sleep (Biphasic Sleep) Is Not Recommended for Older Adults ≥65 Years
Older adults should maintain a consolidated nighttime sleep period of 7–8 hours with a consistent wake time every morning, rather than splitting sleep into multiple periods throughout the day. 1
Why Consolidated Sleep Is Superior
The evidence strongly favors consolidated nighttime sleep over split schedules for several physiological and practical reasons:
Consolidated nighttime sleep yields significantly more total sleep time than split schedules. Research comparing sleep patterns shows that consolidated nighttime sleep produces 8.4 hours of actual sleep, while split sleep schedules achieve only 7.16 hours—a deficit of over 1 hour per day. 2
Age-related circadian changes make consolidated sleep more critical for older adults. The suprachiasmatic nucleus (SCN) undergoes neuronal loss with aging, reducing circadian amplitude and making the sleep-wake system more fragile and less tolerant of schedule disruptions. 3
Sleep schedule regularity is directly associated with meeting sleep duration recommendations in older adults. Those with variability in bed and rise times >60 minutes have 2.38 times higher odds of sleeping less than the recommended 7 hours per night. 4
The Specific Problem with Split Sleep in Seniors
Biphasic sleep patterns fragment the already-compromised sleep architecture of older adults:
Older adults naturally experience reduced sleep efficiency, decreased slow-wave and REM sleep, and increased lighter sleep stages compared to younger adults. 3 Splitting sleep further fragments these already-disrupted sleep stages.
The circadian system in elderly individuals requires stronger environmental cues (3,000-5,000 lux light exposure for 2 hours) to maintain synchronization. 3 Split sleep schedules work against this by providing conflicting temporal signals.
Approximately 57% of older adults already complain of significant sleep disruption with repeated nighttime awakenings. 3 Intentionally splitting sleep exacerbates this fragmentation rather than addressing the underlying problem.
The Correct Approach: Consolidated Sleep with Strategic Napping
Instead of split sleep, older adults should follow this evidence-based pattern:
Maintain one consolidated nighttime sleep period with a fixed wake time every morning, regardless of how much sleep was obtained the previous night. 1 This consistency is the single most important behavioral anchor for sleep regulation.
Limit daytime naps to ≤30 minutes and avoid napping after 2 PM to protect nighttime sleep consolidation. 1 This allows for brief restorative rest without undermining the primary sleep period.
Reserve the bedroom exclusively for sleep and sexual activity, avoiding television, reading, or other stimulating activities in bed to strengthen the bed-sleep association. 1
Critical Caveats About Daytime Sleep in Seniors
Excessive daytime sleep is a red flag, not a solution:
When older adults spend excessive time in bed during the day, multicomponent interventions combining increased daytime physical activity, sunlight exposure, and decreased time in bed during the day can reduce nighttime awakenings. 5
If unable to fall asleep within approximately 20 minutes at night, leave the bedroom and only return when feeling sleepy, thereby strengthening the bed-sleep association rather than fragmenting sleep across the day. 1
When Split Sleep Research Doesn't Apply to Seniors
The one study examining split sleep schedules 2 involved healthy young males (mean age 26.5 years) in a controlled laboratory setting—a population with intact circadian systems and no age-related sleep architecture changes. This research cannot be extrapolated to adults ≥65 years who have:
- Weakened circadian amplitude and phase advancement 3
- Reduced tolerance to schedule shifts 3
- Higher prevalence of comorbid conditions affecting sleep 6
- Already compromised sleep efficiency and architecture 3
The Bottom Line for Clinical Practice
Prescribe consolidated nighttime sleep with these specific parameters:
- Target 7–8 hours of actual sleep in one nighttime block 1
- Fixed wake time every morning (most critical anchor point) 1
- Brief naps (≤30 minutes) before 2 PM only if needed 1
- Bright light exposure (3,000-5,000 lux) for 2 hours in the morning to strengthen circadian rhythms 3
- Cool, dark, quiet bedroom environment 1
This consolidated approach maximizes total sleep time, preserves sleep architecture, and works with—rather than against—the aging circadian system to optimize morbidity, mortality, and quality of life outcomes in older adults.