Napping

Original Editor - Romy Hageman

Top Contributors - Romy Hageman  

Introduction

Naps are brief periods of sleep taken outside of the primary nighttime sleep period. Napping is a complex and deeply ingrained aspect of human life, influenced by culture and spanning across different stages of development. It origins can be traced back to ancient times, likely emerging with the dawn of human civilization. In the initial stages of life, napping is a universal practice among children. However, as children grow and their nighttime sleep becomes more consolidated, the frequency of daytime naps gradually decreases from three to one, and eventually diminishes entirely as they go to primary school. Working adults have less opportunity to nap in the day.

Science behind napping

Brief naps may facilitate neural repair processes, which gradually enhance neurological resilience. During deeper non-rapid eye movement (NREM) sleep stages, cellular damage is repaired, waste products are cleared away, and essential neurochemicals are replenished. A lower coronary mortality is found in individuals who occasional nap. This could relate to temporary blood pressure reductions during naps.

Prevalence of napping

Each bar represents a specific age range, ranging from young children to older adults. This visualization highlights the shifting prevalence of napping across the lifespan, influenced by factors such as developmental changes, lifestyle, and cultural norms.

Napping is a widespread practice in many countries. However, its prevalence varies significantly across different age groups.

While about 50% to 80% of three-year-old children typically take naps during the day, this number decreases to only 9% for children over the age of five. The prevalence of napping rises to 40% among teenagers aged 14 to 19. This increase might be attributed to the growing need for sleep during adolescence and the insufficient opportunity for sleep at night. In Japan, approximately 41.7% of young adults (aged 20-39) and 45.6% of middle-aged adults (aged 40-59) reported occasionally taking naps (minimum of once a week). Only 11.7% of young adults and 14.4% of middle-aged adults reported taking regular naps (more than four times a week).

Napping tends to be more common among older adults compared to younger populations. Studies have shown that the prevalence of napping among older adults varies widely, ranging from 20% to 60% globally, depending on factors such as participants' demographics, definitions of napping, and geographical location. Afternoon napping is less frequent in regions with cooler climates, but it is more prevalent in countries in Latin America, Asia, and Africa, where the afternoon temperatures rise significantly due to the heat of the sun.

Cultural beliefs about napping

Napping is more prevalent in certain countries where there is a cultural belief in the beneficial effects of daytime sleep on health. In china and some Latin American countries it is common practice to take a nap after lunch. Individuals in these regions are more inclined to take a planned nap when experiencing daytime sleepiness or fatigue. In countries where napping is less common, taking a midday nap may be perceived as laziness. People in these countries may make additional efforts to combat sleepiness or fatigue, such as consuming caffeinated beverages to stay awake during the day.

Benefits of napping

Nap benefits can be influenced by various factors. For instance, research indicates that memory enhancements from naps might diminish with advancing age. Additionally, some studies propose that habitual nappers could experience greater benefits from napping in comparison to non-habitual nappers.

• Physical benefits:
  

  This illustration shows the physical benefits of napping.
  • Antioxidant defence
  • Better cardiovascular recovery from psychological stress
  • Better motor learning
  • Enhancement of motor skills
  • Increased brain volume
  • Improvements in motor reaction times
  • Increased relaxation
  • Reduced fatigue
  • Reduced heart disease
    • It is important to limit the nap to 30 minutes or less to avoid negative heart health effects during longer daytime sleep.
  • Reducing pain hypersensitivity to pain stimuly
  • Restoring several immune parameters caused by sleep loss
• Cognitive benefits:
  

  A visual representation of cognitive benefits associated with napping.
  • Better logical reasoning
  • Boost creativity
  • Decreased emotional reactivity
  • Decreased externalizing behaviour problems
  • Enhanced alertness
  • Enhanced memory consolidation:
    • Declarative memory
    • Long term memory
    • Procedural memory
    • Short-term recall
    • Working memory
  • Improved mood
  • Improved self-control
  • Increased objective alertness
  • Increased speed of processing
  • Visual and auditory reaction times improve by 5-10%
  • For different age groups:
    • Toddlers: naps may benefit abstraction and generalization abilities
    • Preschoolers: naps improve cognition and memory and it may also help with the acquisition of new information
    • School-age children: napping is linked to higer verbal IQ en better academic achievement
    • Teens: napping increases overall cognition, both short-term and long-term memory, and protects the learning capacity
    • Young to middle-aged adults: napping increases overall cognition, but especially memory
    • Elderly: planned naps are positive for cognition and declarative memory
• Athletic benefits:
  

  This illustration shows the benefits of napping for athletes. Napping contributes to improved overall performance and well-being in athletes.
  • Decreased delayed onset muscle soreness
  • Decreased fatigue
  • Decreased heart frequency
  • Decreased stress
  • Decreased subjective sleepiness
  • Enhancement of the recovery process
  • Improved anaerobic endurance
  • Improved endurance performance
  • Improved explosive strength
  • Improved jumping performance
  • Improved leg muscle strength
  • Improved reaction time
  • Increased self-rated performance
  • Improved short-term maximal performance
  • Improved sprint times
  • Improved upper-body power performance

Types of naps

• Brief naps (10-15 minutes): gives a meaningful cognitive and physical functioning boost
• Short naps (20-30 minutes): contain N2 sleep and slow waves and provide recovery of alertness
• Longer naps (60-90 minutes): both NREM and REM sleep are important for memory consolidation

Reasons for napping

People can have various reasons for taking a nap. Research indicated five different categories by the acronym DREAM: dysregulative, restorative, emotional, appetitive, and mindful:

• Dysregulative napping: this type of napping accurs due to factors such as irregular work schedules (occupational dysregulation), excessive sleep duration (homeostatic dysregulation), or in response to physical discomfort like illness, pain of preparing for or recovery from exercise (physical of physiological dysregulation).
• Restorative napping: this type of napping is typically observed in individuals experiencing poor sleep quality or duration, fatigue, or those who foresee a night of insufficient sleep and preemptively nap to compensate. Accidental napping also falls into this category.
• Emotional napping: this type of napping is triggered by negative emotions such as stress, depression, or boredom, or as a means to avoid a specific task or social situation.
• Appetitive napping: this type of napping is habitual and enjoyed by individuals who incorporate naps into their daily routines, believing it enhances their performance or well-being.
• Mindful napping: this type of napping is employed as a deliberate strategy to enhance alertness, focus, and energy levels, reduce drowsiness, and capitalize on the perceived benefits of napping.

Tips for effective napping

• Duration: the duration of a nap plays a crucial role in determining its benefits:
  • Research indicates that shorter naps, lastings between 5 to 20 minutes, tend to yield the most significant improvements upon waking. These brief naps primarily involve light non-rapid eye movement (NREM) sleep, which helps restore wakefulness without delving into the deeper slow-wave or rapid eye movement (REM) sleep stages, which can lead to grogginess.
  • On the other hand, longer naps exceeding 30 minutes may have adverse effects on nighttime sleep quality and quantity.
  • Naps of 90 minutes are associated with decreased sprint performances and increased sleepiness in athletes. But napping for more than 35 minutes and less than 90 minutes can be recommended for active people and athletes.
  • However, some studies suggest that naps lasting up to 90 minutes can enhance memory consolidation by allowing for both NREM and REM sleep.
• Timing: the timing of naps is also crucial, influenced by circadian rhythms and the body's sleep drive:
  

  The green line represents the ideal nap window between 1-4 PM, offering benefits such as increased cognitive performance, stress reduction and better nighttime sleep quality. The red line indicates the timeframe where napping is not recommended, closer to bedtime, as this disrupts nighttime sleep patterns.
  • Research suggests that naps taken during the circadian afternoon dip, typically between 1-4 PM, are most beneficial for cognitive performance, stress reduction, and nighttime sleep quality.
    • The cognitive boost from a nap during these hours persist longer than early naps. They tend to sustain the benefits for 2-3 hours post-nap.
  • However, napping too late in the afternoon or evening, especially close to bedtime, can disrupt nighttime sleep patterns.
• Frequency: the frequency of napping needed to sustain benefits varies among individuals:
  • Younger adults without sleep deficits may only need 1-2 brief naps per week for performance enhancement.
  • Older individuals and those with chronic sleep deprivation may require daily napping for optimal function.
• Extra:
  • Ensure getting sufficient sleep the night before napping. Naps should complement proper nighttime sleep, not replace it. If dealing with chronic sleep deprivation, refrain from napping and prioritize improving nighttime sleep habits first.
  • Choose a tranquil environment for napping with minimal light and noise, and comfortable temperatures. Opt for places like beds or couches. Use pillows, earplugs, or eye masks if needed.
  • Consider a ''caffeine nap'' by consuming caffeine before a brief snooze of 15 to 20 minutes. This strategy allows caffeine's effects to synergize with sleep, reducing drowsiness before the caffeine kicks in.
  • Maintain consistent schedules and good sleep hygiene practices. Establish regular bedtimes and wake times to support the circadian rhythm. Create a conducive sleep environment by limiting screen time before bed and avoiding stimulants in the evening.
  • Experiment to find the optimal nap length, frequency, and timing that works best. Since everyone's sleep needs vary, making subtle adjustments can enhance effectiveness and prevent over-napping.

Drawbacks of napping

While brief naps offer numerous benefits, research also highlights the drawbacks of excessive napping during the day:

• When naps become too lenghty, frequent, or irregularly timed, they can compromise the quality and quantity of nocturnal sleep.
• Habitual napping may also indicate underlying health issues.
• Longer naps exceeding 30 minutes result in increased slow-wave deep sleep. This reduction in sleep pressure can make it harder to fall asleep at night, potentially reducing nightly sleep duration by up to 30 minutes.
• Late afternoon and evening naps are linked to disruptions in nighttime sleep patterns. Individuals who nap after 4 PM experience significantly less REM sleep following a late nap. Therefore, naps taken too close to bedtime are not recommended.
• Excessively frequent napping can also lead to the displacement of critical nighttime sleep over the long term. Napping every day of the week is associated with double the risk of insomnia compared to occasional nappers. This may result from a reduction in homeostatic sleep drive or disrupted circadian rhythms due to habitual daytime sleeping.
• Individuals, who nap over 1 hour per day, have a 30% greater mortality.

Conclusion

In summary, brief naps lasting between 10-20 minutes, ideally taken between 1-5 PM, seem to be optimal for most healthy adults, considering the influence of circadian rhythms and sleep patterns. Individual variations in sleep requirements influence the ideal nap routine. Nevertheless, when timed appropriately, these short, strategic naps offer a straightforward method to enhance both mental and physical performance. Frequency of napping is individual, but most likely optimized at 1-3 brief naps per week.

It is important to make clear that napping is not a substitute for nighttime sleep, but more like a added bonus. Always make sure to get enough sleep (7-9 hours) before considering adding napping. Good sleep hygiene, maintaining consistent schedules, and seeking clinical treatment for any underlying sleep disorders are essential. The benefits of napping are supplementary to sufficient baseline sleep. They provide a periodic boost rather than serving as a subsitue for overnight sleep.