Is the true identity of 'Oversleeping in Spring' a disrupted biological clock? Over 90% experience 'Spring morning grogginess'
A survey by Moon Moon Co., Ltd. reveals that 92% of people experience grogginess on spring mornings, significantly impacting their morning performance. Many mistakenly blame temperature changes, while the root cause—a disrupted biological clock due to habits like nighttime smartphone use—is often overlooked.
📋 Article Processing Timeline
- 📰 Published: April 14, 2026 at 17:20
- 🔍 Collected: April 14, 2026 at 09:01
- 🤖 AI Analyzed: April 19, 2026 at 19:23 (130h 21m after Collected)
As the saying goes, 'In spring, one sleeps unaware of the dawn,' spring is a season where people tend to oversleep. However, what modern people suffer from might not be mere 'oversleeping,' but a 'deterioration in the quality of awakening' where the brain doesn't function even after getting up. Moon Moon Co., Ltd., operator of the sleep-aid introduction site 'Kaimin Land,' conducted a 'Survey on Spring Awakening Quality and the Biological Clock' targeting 200 men and women in their 20s to 60s nationwide. The results highlighted a severe reality: over 90% of people feel their 'heads are groggy' on spring mornings, and for about 40% of them, this directly leads to a decline in performance in work and daily life.
Survey Background
Spring is a season where, while sunrise times get earlier, factors that disrupt the autonomic nervous system—such as temperature fluctuations and the stress of a new lifestyle—coincide. Originally, the biological clock needs to shift according to changes in daylight hours. However, in modern lifestyles, this adjustment often cannot keep up, leading to a state where 'the body is awake, but the brain is not working.' In this survey, we explored the true identity of the 'spring grogginess' felt by many, and revealed the 'gap' between the perceived causes and the actual countermeasures taken.
Survey Summary
- 92.0% experience 'spring morning grogginess.' Over 20% feel it 'almost every morning.'
- 42.5% are aware of a 'decline in morning performance.' The largest group says 'it takes 1-2 hours for the engine to start.'
- The top perceived cause is 'temperature differences,' but in terms of lifestyle habits, 'nighttime smartphone use' stands out.
- The go-to countermeasure is 'relying on caffeine.' There is a tendency to prioritize temporary wakefulness over fundamental solutions like regulating the biological clock.
- One in three people suspect their biological clock is disrupted by 'nighttime smartphone/PC use.'
*When quoting the results of this survey, please include the URL of 'Kaimin Land' (https://intiinti.com/goodsleep/).
Detailed Data
Q1: In spring (March-May), do you ever feel your head is groggy or you can't wake up refreshed after getting up in the morning?
- Feel it occasionally: 25.5%
- Feel it 3-4 times a week: 24.0%
- Feel it almost every morning: 22.5%
- Feel it 1-2 times a week: 20.0%
- Hardly feel it: 8.0%
-> A total of 92.0% experience a feeling of not being refreshed on spring mornings. Notably, nearly half of the respondents feel it at a frequency ranging from 'almost every morning' to '3-4 times a week,' suggesting a chronic lack of awakening specific to spring.
Q2: To what extent does spring grogginess affect your work or daily life?
- Affects it a little: 33.0%
- Engine doesn't start for 1-2 hours: 30.5%
- Hardly affects it: 18.0%
- Can't concentrate for the entire morning: 12.0%
- Don't have grogginess in the first place: 6.5%
-> 42.5% answered they cannot concentrate for '1-2 hours' or 'the entire morning.' Spring grogginess may affect not only individual physical sensations but also the productivity of society as a whole.
Q3: What do you think is the possible cause of your head not feeling refreshed in spring?
- Body feels heavy due to temperature differences: 20.7%
- The change of season affects the autonomic nervous system: 20.0%
- The temperature gap (cold at night, warm in the morning): 16.3%
- Hay fever or the effects of its medication: 15.2%
- Unable to switch from the winter sleep rhythm: 6.7%
- Other: 21.1%
-> The top results show that many people attribute it to external environments or physical constitution, such as 'temperature differences' and the 'autonomic nervous system.' On the other hand, only 5.7% cited 'disruption of sleep rhythm' as the cause.
Q4: Are you doing anything to wake up refreshed in the morning?
- Relying on caffeine: 17.7%
- Trying to bask in the morning sun: 16.2%
- Not doing anything in particular: 12.7%
- Doing light exercise or stretching: 12.3%
- Trying to wake up at the same time even on holidays: 11.0%
- Other: 30.1% (Using an alarm clock: 9.7%, Drinking cold water right after waking up: 8.8%, Want to do something but don't know what to do: 5.8%, etc.)
Survey Background
Spring is a season where, while sunrise times get earlier, factors that disrupt the autonomic nervous system—such as temperature fluctuations and the stress of a new lifestyle—coincide. Originally, the biological clock needs to shift according to changes in daylight hours. However, in modern lifestyles, this adjustment often cannot keep up, leading to a state where 'the body is awake, but the brain is not working.' In this survey, we explored the true identity of the 'spring grogginess' felt by many, and revealed the 'gap' between the perceived causes and the actual countermeasures taken.
Survey Summary
- 92.0% experience 'spring morning grogginess.' Over 20% feel it 'almost every morning.'
- 42.5% are aware of a 'decline in morning performance.' The largest group says 'it takes 1-2 hours for the engine to start.'
- The top perceived cause is 'temperature differences,' but in terms of lifestyle habits, 'nighttime smartphone use' stands out.
- The go-to countermeasure is 'relying on caffeine.' There is a tendency to prioritize temporary wakefulness over fundamental solutions like regulating the biological clock.
- One in three people suspect their biological clock is disrupted by 'nighttime smartphone/PC use.'
*When quoting the results of this survey, please include the URL of 'Kaimin Land' (https://intiinti.com/goodsleep/).
Detailed Data
Q1: In spring (March-May), do you ever feel your head is groggy or you can't wake up refreshed after getting up in the morning?
- Feel it occasionally: 25.5%
- Feel it 3-4 times a week: 24.0%
- Feel it almost every morning: 22.5%
- Feel it 1-2 times a week: 20.0%
- Hardly feel it: 8.0%
-> A total of 92.0% experience a feeling of not being refreshed on spring mornings. Notably, nearly half of the respondents feel it at a frequency ranging from 'almost every morning' to '3-4 times a week,' suggesting a chronic lack of awakening specific to spring.
Q2: To what extent does spring grogginess affect your work or daily life?
- Affects it a little: 33.0%
- Engine doesn't start for 1-2 hours: 30.5%
- Hardly affects it: 18.0%
- Can't concentrate for the entire morning: 12.0%
- Don't have grogginess in the first place: 6.5%
-> 42.5% answered they cannot concentrate for '1-2 hours' or 'the entire morning.' Spring grogginess may affect not only individual physical sensations but also the productivity of society as a whole.
Q3: What do you think is the possible cause of your head not feeling refreshed in spring?
- Body feels heavy due to temperature differences: 20.7%
- The change of season affects the autonomic nervous system: 20.0%
- The temperature gap (cold at night, warm in the morning): 16.3%
- Hay fever or the effects of its medication: 15.2%
- Unable to switch from the winter sleep rhythm: 6.7%
- Other: 21.1%
-> The top results show that many people attribute it to external environments or physical constitution, such as 'temperature differences' and the 'autonomic nervous system.' On the other hand, only 5.7% cited 'disruption of sleep rhythm' as the cause.
Q4: Are you doing anything to wake up refreshed in the morning?
- Relying on caffeine: 17.7%
- Trying to bask in the morning sun: 16.2%
- Not doing anything in particular: 12.7%
- Doing light exercise or stretching: 12.3%
- Trying to wake up at the same time even on holidays: 11.0%
- Other: 30.1% (Using an alarm clock: 9.7%, Drinking cold water right after waking up: 8.8%, Want to do something but don't know what to do: 5.8%, etc.)