Some common behaviors in life, when exceeded beyond ’30 minutes,’ can lead to discomfort and even have long-term negative impacts on health. Be cautious~
1. Wearing headphones for no more than 30 minutes
Do you enjoy listening to music with headphones? Dr. Yongmei Yu, Deputy Chief Physician of the Department of Otolaryngology at the First Affiliated Hospital of Kunming Medical University, pointed out in a 2018 article in Healthy Times that when using headphones, especially in-ear headphones, the sound energy cannot spread around, concentrating entirely in the ear canal. The intensity can be high, reaching significant decibel values, making it easy to cause hearing damage. The process of hearing loss is often silent and gradual. In the early stages, even though the hair cells in the cochlea may be partially damaged, they might not be completely dead, and there might be no obvious symptoms. However, the lifespan of these hair cells has already been shortened. People who frequently use headphones are likely to experience early hearing loss.
The normal human hearing range is between 20 Hertz and 20,000 Hertz, with an intensity of 0 decibels to 20 decibels. To protect your hearing, it’s advisable not to wear headphones for continuous music listening for more than 30 minutes, and it’s best to keep the volume at no more than two-thirds of the maximum.
2. Sitting for No More Than 30 Minutes
Prolonged periods of sitting, reclining, or lying down with low energy expenditure during wakefulness fall under sedentary behavior. With the continuous advancement of metabolic research in various fields, sitting for more than 30 minutes at a stretch leads to subtle changes in the body’s metabolism. Some believe that sitting for over 30 minutes at a time may potentially impact human health.
As the duration of sedentary behavior increases, the proximity to diseases also intensifies. A study found that compared to individuals who sit for less than 2 hours a day, those who sit for more than 6 hours a day have a 26.7% increased risk of developing 12 chronic diseases. These diseases include ischemic heart disease, diabetes, depression, migraines, gout, and more.
Given the opportunity, it’s recommended to stand up and stretch for 30-40 minutes. If standing is not possible, performing seated stretches is beneficial. A 5-minute break, listening to music, doing some seated exercises, is also excellent for eye protection.
3. Limit Phone Usage to 30 Minutes
There’s an optimal duration for phone usage too—30 minutes. A study from Iowa State University randomly assigned 230 participants to two experimental conditions: one restricted participants’ smartphone social media usage to within 30 minutes, while the other allowed normal usage.
The final results revealed that participants with restricted phone usage experienced significant improvements in mental health after the 2-week limitation. Negative emotions such as anxiety, depression, and loneliness decreased, while positive emotions increased.
Long-term use of smartphones or computers can cause various eye problems, including dryness, discomfort, pain, tearing, and visual fatigue.
To reduce the negative impact of excessive phone usage, it is recommended to turn off notifications for all but the most essential apps. Designate an area at home where electronic devices are not used, such as the kitchen or bedroom. Set specific time slots each day for activities like checking messages or watching short videos, and avoid continuous phone use for more than 30 minutes.
4. Shower for No More Than 30 Minutes
Extended showering can strip the skin’s surface of protective oils, leading to symptoms like dryness, itching, and, in a closed bathroom, even oxygen deprivation. Generally, a shower within 15 minutes is reasonable, and for a bath, keeping it under 30 minutes is advisable.
There’s no scientifically defined optimal duration for showering, so it’s best to adjust based on factors like personal health and bathing environment.
David Leffell, Director of Dermatologic Surgery at Yale School of Medicine, suggests three skin-friendly bathing practices:
Avoid excessively hot water.
Keep showering time under 30 minutes.
Moisturize before leaving the bathroom. Applying lotion while the skin is still moist helps lock in moisture.
5. Nap for No More Than 30 Minutes
A study published in the journal “Obesity” in 2023 found that individuals who nap for more than 30 minutes are associated with a 41% increased risk of high body mass index (BMI) and metabolic syndrome, particularly in terms of waist circumference, fasting blood sugar, and blood pressure, compared to those who don’t nap.
On the other hand, those who nap for less than 30 minutes show no metabolic health risks and perform better in terms of blood pressure. In general, a nap of 15-30 minutes is considered optimal. Going beyond this time frame can lead to discomfort such as feeling unable to open the eyes, still wanting to sleep, unwillingness to move, and mental fog.
6. Fall Asleep in Less Than 30 Minutes
Characteristics of healthy sleep include falling asleep relatively quickly, generally within 30 minutes. A healthy sleeper experiences sufficient, uninterrupted sleep without frequent awakenings or disturbances by vivid dreams. Upon waking the next day, one should feel mentally alert, without signs of excessive sleepiness or fatigue.
Dr. Zhang Hui, a neurologist at Huashan Hospital, Fudan University, mentioned in a 2023 article on the hospital’s official WeChat account that the time taken to fall asleep should be brief, with the transition to deep sleep occurring within 20 to 30 minutes after falling asleep. If it regularly takes a long time to fall asleep, adjusting bedtime may be advisable. Difficulty initiating sleep may also be related to factors such as anxiety, stress, excessive focus on sleep, and poor habits like using smartphones or watching TV in bed.
If persistent difficulty falling asleep adversely affects physical health and daily life, seeking medical advice is recommended.
