The truth about the 'number 9 rule' in sex.

Many people are putting unnecessary pressure on themselves and turning their bedrooms into stressful spaces by trying to follow an unproven, anecdotal "multiplication table."

The method of calculating sexual frequency using the "9 rule" has long been a topic of discussion among men. This rule involves multiplying the tens digit of the age by 9, with the tens digit representing the number of weeks and the units digit representing the number of times intercourse occurred.

According to this method, a 20-year-old should have sex 8 times a week, a 30-year-old man needs to maintain 7 times every two weeks, and when he reaches 40, the number is 6 times every three weeks. This calculation sounds fun and easy to remember, but if taken seriously as a measure of sexual prowess, it's a harmful "hoax."

Sharing his views on this issue, Dr. Tra Anh Duy, lecturer at the Department of Psychology, University of Social Sciences and Humanities, Ho Chi Minh City, said that the frequency of sexual intercourse tends to decrease with age. The main reasons stem from hormonal changes, cardiovascular health, sleep quality, underlying diseases, medications, life stress, and relationship bonding.

However, each person's physical condition and lifestyle are independent variables. A 35-year-old man who frequently stays up late, is overwhelmed with work pressure, and drinks alcohol heavily may have a lower libido than a 50-year-old who sleeps well, exercises regularly, and has a relaxed state of mind.

According to research by Twenge et al. published in the journal Archives of Sexual Behavior , after peaking around age 25, the frequency of sexual intercourse among adults decreases by an average of about 3.2% per year. This shows that age plays a role, but it cannot be reduced to a rigid calculation.

Doctor Duy advises a patient. Photo: Men's Health.

Dr. Duy asserts that the "number 9 formula" is merely a fun reference tip and not a medical standard. This calculation ignores a range of core factors that determine male performance, such as testosterone levels, erectile dysfunction, diabetes, hypertension, depression, medications, fatigue levels, and partner satisfaction.

"Sexual life shouldn't become a scheduling problem, and certainly not a bedroom KPI," Dr. Duy emphasized.

According to Dr. Duy, a reasonable frequency is one that both partners find comfortable, willing, painless, not overly tiring, and does not negatively impact their health or work the following day. Some couples can manage a few times a week without any problems, while others can do it less frequently but still achieve high satisfaction. The important thing is not just the number of times, but also the quality, emotional connection, safety, and the lasting positive experience.

Instead of relying on anecdotal advice, Dr. Duy recommends that men pay special attention to actual warning signs from their bodies. Men should proactively visit specialized medical facilities for examination if they experience persistent conditions such as decreased libido, difficulty achieving or maintaining an erection sufficient for intercourse.

Additionally, symptoms such as abnormal ejaculation, pain during intercourse, persistent fatigue, loss of natural morning erections, or couples who have been trying to conceive for 6-12 months without success should also consult a doctor.

Source: https://znews.vn/su-that-ve-cong-thuc-so-9-trong-quan-he-tinh-duc-post1656568.html