Your fitness age is more than just a number—it’s a reflection of your overall cardiovascular health and physical wellbeing. At Livity, we’ve developed a scientifically-backed approach to calculating your fitness age that gives you valuable insights into your body’s true condition.

The Science Behind Your Fitness Age

Our fitness age calculation is based on extensive research and validated methodologies from leading cardiovascular fitness studies, including the renowned HUNT Fitness Study from Norway. This large-scale study established the most important factors for fitness assessment in healthy adults, creating a foundation for accurate fitness age determination.

Key Factors in Our Calculation

Our algorithm analyzes seven primary components to determine your fitness age, based on the latest scientific research and population-level health data:

1. VO₂ Max (Maximal Oxygen Uptake)

Your VO₂ max is considered the gold standard for measuring aerobic fitness—it shows how efficiently your body uses oxygen during exercise. We compare your current VO₂ max with age and sex-specific reference values from the FRIEND Registry to assess where you stand compared to others your age. Research from the American Heart Association recognizes VO₂ max as a vital clinical indicator that’s inversely associated with mortality risk.

2. Resting Heart Rate

A lower resting heart rate typically indicates better cardiovascular fitness. Our algorithm evaluates your sleeping heart rate patterns against age and sex-specific references derived from large-scale wearable device studies. Studies show that resting heart rate is a reliable biomarker for measuring cardiovascular health and recovery capacity.

3. Heart Rate Variability (HRV)

HRV measures the variation between heartbeats, reflecting your autonomic nervous system health and stress resilience. Higher HRV is associated with better recovery capacity and overall health. We analyze your 24-hour HRV patterns and compare them with age and sex-specific norms from recent meta-analyses.

4. Vigorous Activity Frequency

How often you engage in vigorous physical activity significantly impacts your fitness age. Our calculation considers the number of days per week you perform sustained vigorous activities (continuous periods of 5+ minutes), aligning with WHO and ACSM exercise guidelines. Vigorous activity is identified when your heart rate reaches 70-85% of your maximum for sustained periods.

5. Vigorous Activity Duration

Beyond frequency, the duration of your vigorous activity sessions matters. We analyze your average minutes of sustained high-intensity activity per day and compare this with established health recommendations. Research shows that 75-150 minutes per week of vigorous activity provides optimal cardiovascular benefits.

6. Sleep Duration

Quality sleep is essential for recovery and health. We compare your average sleep duration to age-specific optimal ranges established by the National Sleep Foundation and recent sleep research. Both insufficient and excessive sleep can impact your fitness age and overall health outcomes.

7. Sleep Consistency

Regular sleep patterns support your circadian rhythm and metabolic health. We analyze the consistency of your sleep and wake times to calculate a sleep regularity score. Studies show that irregular sleep patterns can increase mortality risk by 20-48%.

How We Calculate Your Fitness Age

Your chronological age serves as the baseline, which is then adjusted based on your performance across the seven key metrics above. The formula applies evidence-based impact values for each component:

1. If your metrics exceed the reference values for your age, your fitness age decreases (improved fitness)
2. If your metrics fall below reference values, your fitness age increases (reduced fitness)
3. Each factor is weighted based on its proven impact on health outcomes

The calculation includes sophisticated algorithms to ensure realistic results, including quality filters for data validation and non-linear impact calculations that reflect real-world health relationships.

Understanding Your Results

Your fitness age result provides valuable information about your current health status:

• Fitness Age Lower Than Chronological Age: Your cardiovascular system and overall health markers are performing better than average for your age group
• Fitness Age Higher Than Chronological Age: There are opportunities to improve your health through targeted lifestyle changes

The app also calculates your “achievable age”—a realistic estimate of the fitness age you could reach with consistent, appropriate exercise and lifestyle improvements based on research-backed potential gains.

Scientific Validation

Our approach is built on principles established in peer-reviewed research, including:

• The HUNT Fitness Study, which established the relationship between key health metrics and VO₂ max
• The FRIEND Registry, providing population-level fitness norms from millions of cardiopulmonary tests
• Large-scale wearable device studies analyzing heart rate, HRV, and sleep patterns from millions of users
• Meta-analyses validating the fitness age concept as an effective predictor of mortality risk and cardiovascular health

Our multifactorial approach incorporates seven dimensions of fitness for a comprehensive assessment that goes beyond simple VO₂ max estimates, providing a more complete picture of your health.

Improving Your Fitness Age

Your fitness age isn’t fixed—it can improve with regular physical activity and lifestyle changes. The Livity app provides personalized recommendations based on your individual metrics, helping you target the specific factors that would most effectively lower your fitness age.

By monitoring your fitness age over time, you can track improvements in your cardiovascular health and celebrate your progress toward optimal fitness.

Note: While our fitness age calculation is based on scientific research, it should be used as a motivational and informational tool rather than a medical diagnosis. Always consult with healthcare professionals for personalized medical advice.