Checklists by Age
Longevity Checklist for Your 40s
US guidance on screenings in the 40s, heart risk and activity, plus what smoking and muscle studies can—and cannot—say about living longer.

Your 40s can be a crowded decade, easy to spend on everyone but yourself. Humanic Blue’s checklist looks at the risks that begin to shape living longer and better, and the checks and habits that enter the picture.
This decade adds a few calendar reminders to the familiar habits. The US Preventive Services Task Force (USPSTF) says yearly blood-pressure screening is a reasonable option from 40. Mammography starts at 40 for people covered by its average-risk recommendation, and colorectal screening starts at 45 for adults at average risk. The USPSTF statin guidance concerns cholesterol-lowering medicines for eligible adults ages 40 to 75. The 2026 American College of Cardiology/American Heart Association (ACC/AHA) guideline uses PREVENT, a tool for estimating future cardiovascular risk, from age 30. If you smoke, quitting at 35 to 44 was associated with about 9 more years of life than continuing in a major US study. The CDC recommends muscle-strengthening activity for adults. A separate study using magnetic resonance imaging (MRI) found lower total muscle mass in older groups around age 50 and beyond, mostly in the legs; it did not test training or follow individual muscle loss. Weight, alcohol, mood and menopause-related body changes are also discussed below. The full screening schedule is in What Health Screenings Do You Need in Your 40s?
Key Takeaways
- Quitting smoking at 35 to 44 was associated with about 9 more years of life than continuing, and quitting before 40 with about 90% less excess risk. Supported (observational).
- Several US screenings start or step up in the 40s: the USPSTF calls yearly blood-pressure screening reasonable from 40, recommends mammography every two years from 40 and colorectal screening from 45. Established.
- An MRI study compared different age groups and found lower total muscle mass around age 50 and beyond, mostly in the legs; it did not track the same people over time. Supported, with a design limitation.
The checklist at a glance
| Item | What changes in your 40s | Source |
|---|---|---|
| Blood pressure | Yearly is a reasonable option from 40 | USPSTF |
| Heart risk and statins | PREVENT risk estimate from 30 under 2026 ACC/AHA; USPSTF statin guidance covers 40–75 | USPSTF; 2026 ACC/AHA |
| Lipoprotein(a), or Lp(a), a cholesterol-carrying particle linked to heart risk | Measurement at least once in adulthood recommended | 2026 ACC/AHA |
| Diabetes | American Diabetes Association (ADA): testing by 35 for those not tested earlier because of risk; USPSTF: ages 35–70 with overweight or obesity | ADA; USPSTF |
| Mammography | From 40, every 2 years, for those the USPSTF recommendation covers | USPSTF |
| Colorectal | From 45 for adults at average risk | USPSTF |
| Smoking | Quitting at 35–44 associated with about 9 more years than continuing | Jha et al., NEJM |
| Strength | CDC recommends muscle-strengthening activity on at least two days a week; the MRI study does not test an exercise plan | CDC; Janssen et al. |
| Weight | Long-term gain associated with higher disease risk | Zheng et al., JAMA |
| Alcohol and mood | Suicide is top-five at 35–54; liver disease ranks sixth at 35–44 and fourth at 45–54 | CDC via National Institute of Mental Health (NIMH) |
| Menopause transition | Lean mass (body tissue other than fat) declined and fat gain accelerated in the study | Study of Women’s Health Across the Nation (SWAN) |

Which screenings start or step up in your 40s?
The USPSTF says evidence on the best interval is limited and lists yearly hypertension screening as a reasonable option for adults 40 and older. It recommends mammography every two years from 40 to 74 for people at average risk who were assigned female at birth, and colorectal screening from 45 for adults at average risk. Cervical, HIV, hepatitis C and depression screening also continue when applicable. The details are in What Health Screenings Do You Need in Your 40s?
Risk estimates and medication recommendations answer different questions. The USPSTF recommends a statin for adults 40 to 75 with at least one cardiovascular risk factor and an estimated 10-year risk of 10% or higher. The 2026 ACC/AHA guideline on cholesterol and other blood fats uses the newer PREVENT equations for 10-year risk from ages 30 to 79 and 30-year risk from 30 to 59, with different treatment thresholds. It also recommends measuring Lp(a) at least once in adulthood. Which blood tests matter is covered in What Blood Tests Should I Get for Longevity?
Which eligibility limits matter alongside the new screening ages in this decade?
Smoking: an estimated lifespan difference
The smoking study cited here estimated years of life, rather than a change in a risk marker. In a 2013 New England Journal of Medicine study of more than 200,000 US adults, those who quit at 35 to 44 gained about 9 years of life compared with those who kept smoking. By the authors’ estimate, quitting before 40 avoided about 90% of the extra death risk associated with continued smoking, compared with never smoking. This is not a 90% reduction in every cause of death. Quitting at 45 to 54 still gained about 6 years.
Alcohol and mood. In 2023 CDC data presented by NIMH, suicide ranked fourth among causes of death at ages 35 to 44 and fifth at 45 to 54. Chronic liver disease ranked sixth and fourth, respectively. The CDC says people can lower health risks by drinking less or not at all. The 988 Suicide & Crisis Lifeline takes calls and texts at 988.

What changes with muscle and weight in your 40s?
Strength. In a whole-body MRI study comparing about 470 adults aged 18 to 88, a noticeable difference in total muscle mass appeared around age 50 and beyond, mostly in the lower body. Because researchers compared different age groups rather than following the same people, this identifies an age pattern, not the precise age when one person begins losing muscle. The CDC’s current floor for adults is muscle-strengthening activity at least two days a week plus 150 minutes of moderate aerobic activity, such as brisk walking.
Weight trend. In long-running cohorts of US health professionals, weight gain from early adulthood to 55 “was associated with significantly increased risk of major chronic diseases and decreased odds of healthy aging.” Small yearly gains add up over decades.
Fitness. In the HUNT study, which followed the same people over time, about 1,400 adults completed measured fitness tests about ten years apart. Fitness did not decline at a steady rate: the average fall over about ten years was roughly 3 percent for people in their 20s and about 20 percent for people in their 70s, with a steeper decline in men. Where you stand for your age is covered in Good VO2 Max by Age.
What can comparing different age groups tell us—and what requires following the same people over time?
What changes during the menopause transition?
For women approaching menopause, timing matters. In the Study of Women’s Health Across the Nation (SWAN), lean mass (body tissue other than fat) began to decline and fat gain accelerated at the start of the transition. That’s covered in Protect Muscle During Menopause and, for longer-term risk, Menopause and Longevity.
For men, the 40s checklist with a men’s-health focus is in Healthy Aging for Men in Their 40s.
What’s Interesting
The 40s combine two kinds of item: one-time or periodic tests that are easy to schedule, and slow-moving habits that are easy to postpone. The direct life-years estimate on this list doesn’t come from a test. It comes from the smoking cohort: people who quit at 35 to 44 lived about 9 years longer than those who continued.
What This Means in Practice
The USPSTF specifies which groups are eligible for each screening or preventive medicine. The ACC/AHA uses a different cardiovascular-risk framework, and the CDC activity guidance is a population target. None of these sources tests the combined checklist as a lifespan-extending routine.
Questions for primary care include which screening applies, whether family history changes the starting age and what follow-up an abnormal result would require. For people seeking smoking-cessation support, 1-800-QUIT-NOW connects to a free quitline.
A primary care clinician can cover most of this list. A pharmacist can check vaccines, and a registered dietitian or physical therapist can help with food and training.
Bottom Line
The longevity checklist for your 40s mixes new screenings with habits that start to matter more. Yearly blood-pressure screening becomes a reasonable option, mammography starts at 40 for the USPSTF average-risk population and colorectal screening at 45. In the evidence cited here, quitting smoking at 35 to 44 is associated with about 9 additional years of life compared with continuing. How much any single item adds for an individual is unknown. A preventive visit can put the applicable screenings, cardiovascular-risk calculation and personal history into one plan.
A NOTE FROM LONGEVITY365
We read research, consult expert perspectives and work to make complicated health information easier to understand. What you’re reading here reflects how we’ve interpreted and organized that information. It is educational content—not personal medical advice, diagnosis or treatment guidance.
We’re not perfect, and neither is the available research. Evidence changes, new studies emerge and what’s appropriate for one person may not be appropriate for another.
Use this article as a starting point for your own research and conversations with qualified professionals. Always talk with your doctor or another trusted healthcare professional before making decisions that could affect your health, particularly if you take medications, are receiving treatment, have existing health conditions, are pregnant or have other circumstances that could affect what’s appropriate for you.
Reader Questions
A few questions to carry into the comments or your next conversation. Please leave out identifying or personal medical details.
- 01Which part of this guide feels easiest to turn into a better question for a routine visit?
- 02Where do you still feel the line is blurry between a useful check and more testing than you need?
- 03What would make the next conversation clearer: timing, eligibility, possible harms, or what happens after an abnormal result?
Extra Insights & Sources
The evidence summaries and linked sources behind this article.
What We Know
- Quitting smoking in the 40s is associated with more years of life than continuing. Supported (observational).
- Blood pressure, heart-risk, mammography and colorectal screening start or step up in this decade. Established.
- Janssen and colleagues found lower total muscle mass in older age groups around age 50 and beyond; their comparison cannot establish when an individual begins losing muscle. Supported as an age-group comparison.
- Adult weight gain is associated with more chronic disease and less healthy aging. Supported.
What We Don’t Know
- How much any single habit adds to an individual’s lifespan. Population estimates aren’t personal forecasts. Unknown.
- The best protein intake for people in their 40s. Guidance is currently debated. Contested.
Sources
- USPSTF, Hypertension in Adults: Screening (2021 recommendation): supports screening all adults, confirming a new diagnosis outside the clinic and treating annual screening at 40 or older as a suggested interval; optimal intervals remain uncertain.
- USPSTF, Statin Use for Primary Prevention (2022 recommendation): supports the stated age, risk-factor and 10-year-risk criteria; this is distinct from the newer ACC/AHA lipid framework.
- USPSTF, Breast Cancer: Screening (2024 recommendation): supports biennial mammography from 40 through 74 and the population/exclusions stated.
- USPSTF, Colorectal Cancer: Screening (2021 recommendation): supports starting average-risk screening at 45 and continuing routinely through 75.
- ACC/AHA, 2026 Dyslipidemia Guideline Announcement (professional guideline summary): supports use of PREVENT and once-in-adulthood Lp(a) measurement; treatment still depends on individual risk.
- American Diabetes Association, Standards of Care in Diabetes—2026: Diagnosis and Classification (professional guideline): supports screening all other adults from 35 and repeating at least every three years after a normal result, with earlier risk-based testing.
- Jha et al., 21st-Century Hazards of Smoking and Benefits of Cessation in the United States (New England Journal of Medicine, 2013; prospective cohorts, 202,248 adults): supports the approximately nine years gained by quitting at 35–44 and roughly 90% reduction in excess mortality when quitting before 40; observational comparison, not a randomized trial.
- NIMH, Suicide Statistics (CDC 2023 mortality data): supports the corrected age-specific cause-of-death rankings; rankings describe population deaths, not individual risk.
- CDC, About Moderate Alcohol Use: supports that less alcohol or none carries lower health risk than heavier use and that even moderate use may carry more risk than none.
- CDC, Adult Physical Activity Guidelines (reviewed 2025): supports at least 150 minutes of moderate aerobic activity weekly plus muscle strengthening on two days.
- Janssen et al., Skeletal Muscle Mass and Distribution in 468 Men and Women Aged 18–88 Years (2000; cross-sectional MRI study): supports the age pattern in muscle mass; it cannot establish when an individual begins losing muscle.
- Zheng et al., Weight Gain From Early to Middle Adulthood and Health Outcomes Later in Life (JAMA, 2017; cohorts of 92,837 women and 25,303 men): supports associations between weight gain through age 55 and later disease/healthy-aging outcomes; observational, recalled early-adult weight and predominantly white health-professional cohorts.
- Greendale et al., Changes in Body Composition and Weight During the Menopause Transition (JCI Insight, 2019; longitudinal SWAN cohort): supports accelerated fat gain and lean-mass decline around the final menstrual period; applies to the study population and does not by itself establish an intervention effect.
- Stensvold et al., Longitudinal Change in Peak Oxygen Uptake Across the Adult Lifespan (HUNT, 2020; 1,431 adults retested about 10 years later): supports a nonlinear age-related fitness decline; population averages are not an individual forecast.
Photo credits
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