This age window is the most important decade for your health — 3 habits to take up immediately

Talk about pour decisions.

While the effects of partying late into the night may not be apparent in your 20s, a new study out of Finland suggests that all that revelry finally catches up to you at 36.

Researchers advise that the decade between 36 and 46 is a critical time for shaping future health, even going so far as to highlight three wholesome habits to increase the odds of a long, healthy life.

“The decade between 36-46 is important as it marks the bridge to the later years of life,” Dr. Angela Wilson, a gynecologist at Montefiore Einstein Advanced Care in NYC, told The Post.

“The risk of various diseases increases, and prevention, early diagnosis and intervention are paramount,” added Wilson, who was not involved in the new research.

The study followed a few hundred children born in the Finnish city of Jyväskylä in 1959 until their early 60s.

Mental and physical health data were collected when the participants were 27, 36, 42, 50 and 61.

Researchers assessed their blood pressure, waist size, blood sugar, cholesterol and other blood fats as participants answered questions about their psychological wellbeing.

The study authors noted whether they smoked, drank heavily or exercised less than once a week at any point in time. These three vices fueled mental and physical woes, often felt as early as 36.

“Our findings highlight the importance of tackling risky health behaviors, such as smoking, heavy drinking and physical inactivity, as early as possible to prevent the damage they do from building up over the years, culminating in poor mental and physical health in later life,” said lead study author Tiia Kekäläinen, a health scientist who focuses on aging.

The results, recently published in the Annals of Medicine, come amid a startling increase in heart disease, stroke and some cancers among people under 50.

While researchers are still investigating the exact reasons, certain lifestyle factors and environmental exposures are being implicated in these rising rates.

Obesity, alcohol consumption, smoking and exposure to environmental toxins are among the leading culprits.

“When it comes to cardiovascular disease or diabetes, for example, those looking to reduce their risk typically focus on behavioral factors such as diet and physical activity,” environmental epidemiologist Maayan Yitshak-Sade told The Post.

“Even small changes in our daily lives — such as improving ventilation while cooking or walking instead of driving when possible — can significantly reduce these harmful exposures and consequently reduce cardiovascular risk,” added Yitshak-Sade, an associate professor in the Department of Environmental Medicine at the Icahn School of Medicine at Mount Sinai.

Dr. Sanjai Sinha, an internist with Mount Sinai’s Hudson Yards practice, said it’s important to avoid smoking and drinking and establish good habits around exercise, diet and sleep — just not necessarily from 36 to 46.

“I don’t agree that there is a magic decade to get healthy, rather the earlier the better,” he told The Post.

He said it’s crucial to be proactive before hormone levels naturally decline, making it harder to change routines.

Lower testosterone “can lead to gradually lower muscle strength or energy levels,” Sinha explained. “Most women are not in menopause yet, but once that happens (average age: 51), issues with sleep, joint aches, energy, brain fog all can occur.”

Dr. Alice S. Teich — a primary care doctor at Montefiore Medical Group in Westchester — echoed the need for quitting smoking, cutting back on alcohol and aiming for daily movement and weekly structured exercise.

She noted that it’s quite common to feel the cumulative effects of lifestyle choices, like weight gain, elevated blood pressure, fatigue and stiffness, between 36 and 46.

“The key isn’t perfection — it’s taking action,” Teich told The Post. “Establishing consistent, healthy habits during this window can significantly reduce long-term risk and improve quality of life.”