Diet, Exercise, Healthy Habits

The Longevity Tiers

Last updated: April 9, 2026

Crissman LoomisNovember 1, 2024

When I released v2.0 of the True Age calculator, I adjusted the baseline to account for the average American level of each intervention. The results challenged many common assumptions about health. While everyone talks about superfoods and supplements, simple activities like walking has many benefits

How This Analysis Works

I’ve converted complex mortality statistics into a simple metric: years added to life beyond what average Americans already achieve. For example, the average American walks 4,000 steps daily, gaining 3.3 years of life compared to being sedentary. The numbers I share are additional years you could achieve on top of this baseline.

These figures are based on a 40-year-old man. Women typically gain 10% less benefit, while someone 10 years younger gains about 10% more.

Understanding the Chart

Looking at the data visualization, each intervention can combine two components:

• Grey bars extending left show the years of life the average American already gains from current habits. For example, Americans already gain some benefit from their fruit and vegetable consumption—this is built into the baseline.
• The green bars extending right show the additional years you could gain by optimizing the intervention. The sauna bar is entirely green because most Americans don’t use saunas, representing a pure opportunity for improvement.
• Red bars extending right show years of life lost from harmful habits that should be eliminated. Smoking shows both grey and red—the grey represents the years lost because some Americans smoke, while the red represents the additional years that could be added by quitting to current smokers.

This format helps explain why some heavily promoted interventions like eating more vegetables show relatively modest green bars—Americans are already capturing much of the benefit (shown in grey). Meanwhile, interventions like walking and sauna show large green bars because they represent primarily untapped potential.

The Longevity Tiers

The chart reveals clear groupings in the potential benefits of different interventions. I’ve organized these into tiers based on the additional years they can add to life:

• S-Tier: 7+ years added
• A-Tier: 2-4 years each
• B-Tier: 1-2 years each
• C-Tier: 6-11 months each
• D-Tier: 2-5 months each

S-Tier: The Walking Revolution (7+ years)

Walking stands alone at the top, offering an additional seven years beyond the 3.3 years the average American gains from their 4,000 steps daily. At 12,000 steps daily, that’s 10.3 years of added life expectancy. The benefit comes only from walking; running the same distance counts as aerobic exercise.

The Benefits of Walking For Longer Life

It can feel like the comforts of modern life conspire to keep us from moving around.

Starting small works: each additional 1,000 daily steps beyond your current level adds about 0.8 years to life. Park farther away, take walking meetings, or do your errands on foot. Your phone or watch can track steps automatically, making this the easiest intervention to measure.

A-Tier: The Core Four (2-4 years each)

The Exercise Trinity leads this tier:

• Aerobic exercise: 2.6 years
• HIIT (High-Intensity Interval Training): 3.2 years
• Strength training: 2.3 years

Each requires just 1-2 sessions weekly for full benefits. You can combine them efficiently: a HIIT session with jogging between sprints covers aerobic and high-intensity training in one workout.

The fourth A-tier intervention surprises most people: regular sauna use adds 4.0 years when done 4-7 times weekly. While rare outside Finland, you have options:

• Traditional sauna at a gym
• Hot bath (provides partial benefits)
• Infrared sauna blankets

Smoking cessation also appears here, with the actual benefit being more significant than shown since our baseline includes current smokers. If you smoke, this becomes your top priority.

B-Tier: Daily Habits That Matter (1-2 years each)

These interventions punch above their weight, requiring minimal time for significant gains:

• Coffee or tea (1.7 years): 2.5 cups of drip coffee or 5 cups of tea daily
• Nuts (1.4 years): Just 20g (about 20 almonds) daily. Timing matters—small daily portions work better than larger weekly ones
• Whole grains (1.7 years possible beyond average intake): A daily bowl of oatmeal or two slices of whole-grain bread
• Glucosamine (1.2 years): Evidence suggests longevity benefits, but optimal dosage remains unclear
• Fish (1.1 years): 200g daily

What Is Longevity? Meaning & Science-Backed Habits

If you’re in your 30s, 40s, or beyond and starting to think about how long you’ll live — and more importantly, how well — you’re asking the right questions.

C-Tier: Strategic Additions and Subtractions (6-11 months)

What to eliminate:

• Sugary beverages
• Processed meats
• Red meat
• Daily eggs (one every other day is fine)

What to add:

• Legumes (8 months): One serving daily
• Daily flossing (6 months)

D-Tier: Still Worthwhile (2-5 months)

These often-hyped interventions offer modest returns:

• Fruits and vegetables (4 months each)
• Weekly spicy peppers (3 months)
• Decaf coffee (3 months)
• Brushing teeth nightly (2 months)

Dairy becomes concerning only above 4 cups daily. Between zero and two cups shows a negligible effect on longevity.

Coffee vs Tea Benefits: Which is Better on Health

Are you an avid coffee drinker? Did you know that brewed or filtered coffee is healthier than instant or decaffeinated? This article dives deep to the pros and cons of drinking coffee. Find out if you're taking it the healthier way!

Practical Implementation

Looking at the chart, a clear strategy emerges. The top six interventions (walking, sauna, HIIT, smoking cessation, aerobic exercise, and strength training) account for about 60% of the potential benefit. Start there.

Some combinations work naturally together:

• Morning walk to get coffee (S-tier + B-tier)
• HIIT with jogging recovery periods (two A-tier interventions)
• Strength training followed by sauna at the gym (two A-tier interventions)
• Oatmeal with nuts for breakfast (two B-tier interventions)

Using This Framework

When evaluating any health intervention, consider its mortality reduction:

• S-tier: 48%+ reduction
• A-tier: 24%+ reduction
• B-tier: 12%+ reduction
• C-tier: 6%+ reduction
• D-tier: <6% reduction

This reveals surprising insights. Reducing sleep from 9 to 7 hours reduces mortality by 27% (A-tier), while increasing it from 5 to 7 hours reduces mortality by 3% (D-tier). Weight loss with a BMI over 27.5 reduces mortality by 15% (B-tier).

The data challenge many common assumptions about health optimization. Walking outperforms nearly every supplement and superfood combined. Regular sauna use beats most dietary interventions. And many popular health practices barely move the needle.

How to Sleep Better for Longevity and Health

In recent years, sleep has become the darling of health and longevity experts. Everywhere you turn, someone’s extolling the virtues of a perfect night’s rest, claiming it’s the key to a longer, healthier life.

Your Personal Opportunity

Remember, these tiers are based on improvement beyond the average American baseline. If you’re below average in any intervention—say, never flossing—then that intervention becomes more powerful for you. Daily flossing could jump from a C-tier to a B-tier intervention. Similarly, if you walk less than 4,000 steps daily, your potential benefit from walking increases beyond even the S-tier numbers shown.

Use the True Age calculator to determine how these interventions would affect you based on your current habits. It will analyze your baseline and show you which interventions benefit you most.

Ready to reap the full benefits of the S and A-tier interventions? Join the Unaging Challenge for a structured approach to implementing these highest-impact changes. Focus your energy where it matters most: Start by walking more, finding a sauna or hot bath routine, and adding brief but intense exercise sessions. The rest is fine-tuning.