Science

What is Biological Age?

Your biological age measures how old your body seems based on various health markers, rather than just the number of years you've lived (chronological age).

Key Factors:

1. HRV (Heart Rate Variability):

   • HRV is the variation in time between each heartbeat. It's a good indicator of your heart health and overall fitness.

   • Higher HRV generally indicates better cardiovascular health and lower stress levels.

2. VO2 Max:

   • VO2 Max measures the maximum amount of oxygen your body can use during intense exercise. It reflects your aerobic fitness level.

   • Higher VO2 Max values mean better endurance and overall fitness.

How We Calculate Your Biological Age:

HRV Calculation:

We use the following data points [extrapolated from this study] for HRV and corresponding ages:

• Ages: [18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 70, 80, 90]

• HRV (male): [85, 74, 61, 56, 49, 43, 38, 34, 32, 31, 23, 18, 17]

• HRV (female): [75, 66, 57, 53, 47, 42, 37, 34, 33, 31, 23, 18, 17]

Example:

• Let's say you have an HRV value of 45.

• For males, an HRV of 45 falls between the values for ages 35 (HRV 49) and 40 (HRV 43).

To find your exact HRV-based age, we interpolate between these points:

• Proportion Calculation:

  • Proportion = (HRV - HRV at age 40) / (HRV at age 35 - HRV at age 40)

  • Proportion = (45 - 43) / (49 - 43) = 2 / 6 = 0.33

• Interpolated Age Calculation:

  • Age Difference = Age at 35 - Age at 40 = 35 - 40 = -5

  • Interpolated Age = Age at 40 + (Proportion * Age Difference)

  • Interpolated Age = 40 + (0.33 * -5) = 40 - 1.65 = 38.35

Therefore, your HRV-based age is 38.35.

VO2 Max Calculation:

We use the following data points [extrapolated from this study] for VO2 Max and corresponding ages:

• Ages: [18, 23, 28, 33, 38, 43, 48, 53, 58, 63, 68, 73, 78]

• VO2 Max (male): [58, 56, 53, 51, 48, 45, 42, 40, 37, 35, 32, 30, 27]

• VO2 Max (female): [49, 44, 40, 37, 35, 33, 30, 28, 26, 24, 22, 20, 18]

Example:

• Let's say you have a VO2 Max value of 42.

• For males, a VO2 Max of 42 falls between the values for ages 43 (VO2 Max 45) and 48 (VO2 Max 42).

To find your exact VO2-based age, we interpolate between these points:

• Proportion Calculation:

  • Proportion = (VO2 Max - VO2 Max at age 48) / (VO2 Max at age 43 - VO2 Max at age 48)

  • Proportion = (42 - 42) / (45 - 42) = 0 / 3 = 0

• Interpolated Age Calculation:

  • Age Difference = Age at 43 - Age at 48 = 43 - 48 = -5

  • Interpolated Age = Age at 48 + (Proportion * Age Difference)

  • Interpolated Age = 48 + (0 * -5) = 48

Therefore, your VO2-based age is 48.

Average Biological Age:

If we have both your HRV and VO2 Max values, we calculate an average of the two.

Example:

• HRV-based age: 38.35

• VO2-based age: 48

• Average Biological Age = (38.35 + 48) / 2 = 86.35 / 2 = 43.18

Why It Matters:

By understanding your biological age, you get a clearer picture of your overall health and fitness. If your biological age is lower than your chronological age, it indicates you are in good health. If it’s higher, it might be a sign to focus more on improving your fitness and health habits.

We hope this helps you understand how we calculate your biological age. Thank you for being a valued user of our app!

Zhang, Z., Pi, Z., & Liu, B. (2020). Inter- and intraindividual variability in daily resting heart rate and its associations with age, sex, sleep, BMI, and time of year: Retrospective, longitudinal cohort study of 92,457 adults. PLOS ONE, 15(1), e0227709. https://doi.org/10.1371/journal.pone.0227709

Natarajan, A., Pantelopoulos, A., Emir-Farinas, H., & Natarajan, P. (2019). Heart Rate Variability with Photoplethysmography in 8 Million Individuals: Results and Scaling Relations with Age, Gender, and Time of Day. bioRxiv. https://doi.org/10.1101/772285

Umetani, K., Singer, D. H., McCraty, R., & Atkinson, M. (1998). Twenty-Four Hour Time Domain Heart Rate Variability and Heart Rate: Relations to Age and Gender Over Nine Decades. Journal of the American College of Cardiology, 31(3), 593–601.

Yashin, A. I., Akushevich, I. V., Arbeev, K. G., Akushevich, L., Ukraintseva, S. V., & Kulminski, A. (2006). Insights on aging and exceptional longevity from longitudinal data: Novel findings from the Framingham Heart Study. AGE, 28(4), 363–374. https://doi.org/10.1007/s11357-006-9023-7

Zhang, D., Shen, X., & Qi, X. (2016). Resting heart rate and all-cause and cardiovascular mortality in the general population: a meta-analysis. CMAJ, 188(3), E53-E63. https://doi.org/10.1503/cmaj.150535

Zulfiqar, U., Jurivich, D. A., Gao, W., & Singer, D. H. (2010). Relation of high heart rate variability to healthy longevity. The American Journal of Cardiology, 105(8), 1181-1185. https://doi.org/10.1016/j.amjcard.2009.12.022

Kaminsky LA, Arena R, Myers J. Reference Standards for Cardiorespiratory Fitness Measured With Cardiopulmonary Exercise Testing: Data From the Fitness Registry and the Importance of Exercise National Database. Mayo Clin Proc. 2015 Nov;90(11):1515-23. doi: 10.1016/j.mayocp.2015.07.026. Epub 2015 Oct 5. PMID: 26455884; PMCID: PMC4919021.