What Is Bio Age?

In traditional thinking, age is irreversible: the older you are, the less healthy you become.
Every 365 days, your age increases by one year, bringing you one step closer to aging and death.

However, reality tells a different story. Two people of the same chronological age can have vastly different health conditions.
Someone with poor lifestyle habits may develop high blood pressure or elevated blood sugar in their 40s,
while someone who exercises consistently may still maintain healthy cardiovascular function in their 50s.

Chronological age only tells us how long we have lived, not how well we have lived.
To address this limitation, scientists in the field of longevity medicine introduced the concept of Biological Age.

Biological age reflects the body’s true physiological state of aging—a kind of internal biological clock—which may be higher or lower than chronological age.
If your biological age is lower than your chronological age, it generally indicates better health and a greater potential for longevity.

PeakWatch’s Bio Age is built upon this scientific insight. By integrating your sleep, activity, and fitness data, PeakWatch calculates a comprehensive Bio Age.
It doesn’t just tell you how long you’ve lived—it helps you understand how healthy you are living.

2. What Is the Pace of Aging?

Biological age reflects your body’s long-term functional state.
But if you want to understand “How have I been doing over the past two weeks?”, you need to look at the pace of aging.

Different aging paces have different meanings:

  • < 0: Younger Faster
  • 0–0.8: Younger
  • 0.8–1.2: Normal Range
  • 1.2–2: Aging
  • > 2: Aging Faster

3. Which Metrics Are Used to Calculate Bio Age?

To calculate body age accurately, PeakWatch does not rely on a single day of activity or one night of sleep.
Instead, it comprehensively analyzes three core dimensions that strongly influence human longevity: Sleep, Sport (Physical Activity), and Fitness.

Sleep

Sleep accounts for nearly one-third of our lives and is critical for physical recovery.

  • Sleep duration: Adequate sleep duration is the foundation of good sleep quality. Healthy adults are recommended to sleep 7–9 hours per night.
  • Sleep regularity: Consistent bedtimes and wake-up times help maintain normal circadian rhythms and support recovery.

Sport (Physical Activity)

Physical activity supports metabolism and overall health.

  • Aerobic duration (Zone 1–3): Regular aerobic exercise strengthens the cardiopulmonary system and improves cardiovascular health.
  • High-intensity duration (Zone 4–5): High-intensity training efficiently improves maximal oxygen uptake (VO₂max).
  • Strength training duration: Strength training helps increase muscle mass, raise basal metabolic rate, improve muscular function, and reduce the risk of falls and injuries.
  • Step count: Steps are the most common activity metric and reflect overall daily movement levels.

Fitness

Fitness represents the long-term outcome of consistent physical activity and reflects your reserve of health.

  • VO₂max: A higher VO₂max indicates stronger cardiorespiratory fitness and better cardiovascular health.
  • Resting heart rate: A lower resting heart rate generally reflects better cardiovascular fitness. Psychological stress can also influence resting heart rate.
  • Lean mass: Lean mass refers to body weight excluding fat (including muscle and bone). It is often a better indicator of health than body fat percentage.
    For example, individuals with long-term undernutrition may have low body fat but also low lean mass, indicating poor health.

Note: Body Age is based on scientific literature and population-level reference values.
It is not a medical test or diagnostic tool. Always consult healthcare professionals for medical advice.

References

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