If you’ve heard of billionaire Bryan Johnson, you’ve likely encountered the phrase “bio age testing.”
Johnson, a prominent figure in the longevity movement and the subject of the Netflix documentary Don’t Die, has propelled the concept of "biological age" into mainstream discourse. His highly publicized quest, dubbed "Project Blueprint," aims to achieve the lowest possible biological age, purportedly reversing the aging process. This ambitious undertaking reportedly costs him millions of dollars annually, invested in an extensive and highly regimented protocol of anti-aging treatments.
Johnson’s daily regimen is meticulously documented and involves dozens of daily supplements, weekly acid peels, injections to boost collagen production, hyperbaric oxygen therapy, and even plasma infusions derived from his 17-year-old son. To validate the efficacy of these interventions, Johnson frequently undergoes numerous sophisticated tests to assess his biological age. He claims these tests indicate a significant reduction in his bio age, reportedly making him 5.1 years younger than when he began his quest. This assertion suggests he is, quite literally, aging in reverse.
However, Johnson’s claims have not been universally accepted. A New York Times exposé, for instance, presented a conflicting narrative, suggesting that his biological age had, in fact, increased by 10 years. This disparity highlights the nascent and sometimes controversial nature of bio age testing and its interpretation. Despite these debates, Johnson’s "don’t die" crusade continues to capture significant public attention, fueling a growing interest in biological age and its measurement.
The phrase "bio age testing" has become a frequent topic on popular health and wellness podcasts, featuring discussions by influential figures such as Peter Attia, Joe Rogan, and Andrew Huberman. A simple online search reveals dozens of advertisements for mail-order blood or urine testing kits, promising to reveal one’s biological age, pace of aging, and other personalized health metrics. With the increasing accessibility and affordability of these tests, it’s natural for individuals to question their utility and relevance for personal health management. The central question for many is: Should I or my clients engage in bio age testing, which test is most reliable, and crucially, what actionable insights can be derived from the results?
Understanding Biological Age: Beyond Chronology
Your biological age, often referred to as bio age, represents the functional and physiological age of your cells and tissues. This is distinct from your chronological age, which is simply the number of years you have lived since birth. While chronological age is a fixed measure, biological age is dynamic and can be influenced by a multitude of factors, reflecting the cumulative impact of genetics, lifestyle choices, and environmental exposures on your body’s molecular and cellular health.
Consider two hypothetical 50-year-old men, Chang and Jabari. Chang leads a sedentary lifestyle, works at a desk, spends his free time watching television, resides in a highly polluted urban environment, consumes processed foods, and smokes regularly. In stark contrast, Jabari, also 50, engages in consistent physical activity several times a week, lives in a pristine mountainous region, abstains from smoking, prioritizes a diet rich in fruits and vegetables, practices meditation, and spends his evenings gardening. While both share the same chronological age, scientific principles suggest that Jabari’s biological age would likely be significantly younger than Chang’s, due to his healthier lifestyle and environment minimizing cellular damage and promoting regenerative processes. This illustrates that while genetics play a role, lifestyle choices are powerful determinants of how quickly our bodies age at a cellular level.
The Science of Measuring Biological Age
Biological age testing kits aim to quantify the aging process by measuring specific biological markers, or biomarkers, that are known to change with age. These biomarkers provide insights into the health and function of cells and physiological systems.
Telomere Analysis: One common approach focuses on the length of telomeres, which are protective caps found at the ends of chromosomes. Telomeres shorten with each cell division, acting as a kind of cellular clock. Critically short telomeres are associated with cellular senescence (aging) and are implicated in various age-related diseases. Researchers use tests like the flow-FISH test to measure telomere length in clinical settings, particularly when genetic diseases linked to telomere dysfunction are suspected. However, the commercial qPCR telomere test, often marketed directly to the public, is generally not used in robust scientific research or clinical diagnostics, raising questions about its reliability for predicting aging in healthy individuals. While intriguing, the direct correlation between telomere length in healthy individuals and overall longevity remains a subject of ongoing scientific debate.
DNA Methylation and Epigenetic Clocks: A more sophisticated and widely researched method involves measuring DNA methylation, a physiological process where methyl groups are added to DNA molecules. This epigenetic modification influences gene expression without altering the underlying DNA sequence. The patterns and rates of DNA methylation change predictably with age, making them powerful indicators of biological age. Scientists have developed "epigenetic clocks," such as the Horvath Clock and DunedinPACE, which analyze specific methylation sites across the genome to estimate biological age and even the pace of aging. These tools were initially developed as research instruments to study the impact of various factors (lifestyle, environment, pharmaceuticals) on aging. While they offer valuable insights, commercial versions, typically costing around $300, usually analyze methylation patterns from a blood sample. It’s important to note that aging can occur at different rates in different organs and tissues, meaning a blood-based test may not provide a complete picture of organ-specific aging. Therefore, DNA methylation tests, while scientifically promising, are not a substitute for comprehensive medical check-ups.
Standard Biomarkers in Routine Care: It’s important to recognize that many individuals are already tracking relevant biomarkers of aging through routine medical examinations. Common indicators such as blood pressure, cholesterol levels (LDL, HDL, triglycerides), and blood glucose (fasting glucose, HbA1c) are well-established predictors of the risk for chronic diseases like cardiovascular disease and type 2 diabetes—leading causes of premature mortality. Monitoring these parameters allows for proactive health management, often guiding lifestyle interventions or medical treatments to mitigate future health risks.
The Purpose and Benefits of Biomarker Testing
Biomarker testing serves as a proactive tool for wellness monitoring, shifting the focus from reactive disease management to preventative health. By tracking these indicators, individuals can gain an earlier understanding of potential health trajectories, rather than waiting for overt disease symptoms to manifest.
For many, receiving objective biomarker data can act as a powerful motivator. Discovering that one’s bone density, for example, corresponds to someone significantly older might provide the impetus needed to consistently engage in strength training. Similarly, a high inflammatory marker could prompt a reevaluation of dietary habits.
Moreover, biomarkers offer quantifiable data, enabling individuals to objectively track and evaluate the impact of various health-related interventions. Regularly monitoring blood pressure, for instance, might reveal that consistent physical exercise significantly improves readings, while a late-afternoon energy drink has a detrimental effect. This data-driven feedback loop empowers individuals to make informed adjustments to their lifestyle choices, optimizing their health outcomes over time.
Accessible Biomarkers: Free Tests for Longevity Insight
You don’t need to be a billionaire to gain valuable insights into your biological age. Before the advent of high-tech, blood-based bio age tests, researchers relied on a suite of simple, scientifically validated, and often free physical assessments to calculate the pace of aging in study participants. These accessible tests provide an underappreciated window into your physical fitness, balance, and overall resilience.
Free Biomarker Test #1: The Sitting-Rising Test (SRT)
The Science: A robust body of evidence indicates a strong correlation between physical fitness, strength, and longevity. Muscles are not merely movers; they are endocrine organs that secrete anti-inflammatory substances, regulate blood sugar, slow cellular aging, and protect arterial linings. This multifaceted role significantly reduces the risk of age-related diseases such as type 2 diabetes, hypertension, and heart disease. Beyond strength, balance is a critical indicator of healthspan. Research involving 1,700 individuals found that middle-aged or older adults unable to stand on one foot for at least 10 seconds faced double the risk of mortality within the subsequent seven years.
The Sitting-Rising Test (SRT) simultaneously assesses both strength and balance, offering a comprehensive snapshot of functional mobility. A 12-year study of 4,200 adults (aged 46-75) demonstrated that participants with lower SRT scores had a significantly higher risk of dying from cardiovascular disease.
How to Measure It:
- Begin by standing upright.
- Lower yourself to the floor into a crisscross-legged sitting position.
- From this position, stand back up, keeping your legs in the same crisscross posture.
- Observe how many times you needed to use a part of your body (e.g., hand, shin, knee, forearm) for support or leverage during the process.
Scoring: Start with 10 points. Deduct one point for each body part used for support. Subtract half a point if you became unsteady or lost your balance. A lower score indicates potential areas for improvement in balance, coordination, muscle strength, power, and overall mobility.
Free Biomarker Test #2: Grip Strength
The Science: Similar to the SRT, your grip strength offers a powerful proxy for overall muscular fitness. Weakness in the hand muscles often correlates with generalized muscle weakness throughout the body. Poor grip strength is also a robust predictor of future muscle weakness and functional decline. One longitudinal study revealed that individuals with weak grip strength were more likely to exhibit slower walking speeds, difficulty rising from a chair, inability to perform rigorous housework, and challenges climbing stairs 25 years later.
Low grip strength has been consistently associated with:
- Increased risk of cardiovascular disease
- Higher incidence of stroke
- Greater risk of cancer mortality
- Reduced cognitive function
- Higher all-cause mortality
Notably, one study even suggested that grip strength was a more reliable indicator of longevity than blood pressure.
How to Measure It:
- Grab a standard tennis ball.
- Squeeze the ball as hard as you can and hold for as long as possible.
Interpretation: Holding a strong squeeze for 15 to 30 seconds is considered adequate. Achieving 90 seconds places you well above average, typically in the upper-third percentile. If you struggle to hold for 15 seconds, it may indicate a need to address overall strength. While squeezing a ball directly improves grip, significant improvements in overall health and fitness require a holistic approach to exercise. For a more precise measurement, a hand-held dynamometer, available at many occupational therapy clinics and some gyms (or for purchase, costing $100-$500), can provide objective data.
Free Biomarker Test #3: One-Leg Stand Test
The Science: The ability to balance on one foot for an extended period is a crucial indicator of neurological, muscular, and proprioceptive health. It directly correlates with a reduced risk of falls, which are a leading cause of injury-related death among older adults. Maintaining balance requires the coordinated effort of multiple bodily systems, including the eyes, inner ear (vestibular system), skeletal muscles, and brain. Various chronic conditions such as diabetes, heart disease, and cancer can impair these systems, thereby affecting balance. Consequently, an inability to stand on one foot can serve as an early warning sign of deteriorating health and fitness.
How to Measure It:
- Stand near a wall or chair for safety, if needed.
- Keep your eyes open and hands on your hips.
- Lift your dominant leg off the ground and start timing.
- Stop the clock as soon as your foot touches the ground.
- Repeat the test with your non-dominant leg.
Interpretation: Compare your times to the following age-matched averages derived from a Duke University study:
| Age | Seconds on one leg (males) | Seconds on one leg (females) |
|---|---|---|
| 30-39 | 59 | 56 |
| 40-49 | 56 | 55 |
| 50-59 | 42 | 48 |
| 60-69 | 40 | 38 |
| 70-79 | 27 | 25 |
| 80+ | 13 | 11 |
Free Biomarker Test #4: Assessing Fatigability
The Science: While occasional tiredness after a late night is normal, persistent and unexplained exhaustion that interferes with daily life is termed fatigue. This goes beyond physical weariness, often encompassing mental dullness and emotional exhaustion. Fatigue can be an early indicator that something is amiss within the body. After ruling out common culprits like excessive caffeine, dehydration, alcohol, medication side effects, chronic stress, or inappropriate exercise levels, persistent fatigue often points to underlying health issues such as sleep disorders, anemia, obesity, depression, cancer, or diabetes.
For individuals aged 60 and older, fatiguability—the degree to which one feels worn out after an activity—is a significant predictor of longevity. Research from the University of Pittsburgh Medical Center has linked higher fatiguability scores to an increased risk of future mortality. Other studies have connected high fatiguability to declines in gait speed, walking ability, and other fitness metrics.
How to Measure It: Use the Pittsburgh Fatigability Scale. Rate how fatigued you think you would feel after completing the following activities, using a scale of 0 (no fatigue) to 5 (extreme fatigue):
| Activity | Duration | Score (0 to 5) |
|---|---|---|
| Leisurely walking | 30 minutes | |
| Brisk or fast walking | 1 hour | |
| Light household activity | 1 hour | |
| Heavy gardening or yard work | 1 hour | |
| Watching television | 2 hours | |
| Sitting quietly | 1 hour | |
| Moderate-to-high intensity strength training | 30 minutes | |
| Participating in a social activity | 1 hour | |
| Hosting a social event for 60 minutes | 1 hour | |
| High intensity activity | 30 minutes | |
| Add all scores: |
Interpretation: A total score below 15 suggests good energy resilience. Scores between 15 and 24 warrant attention, serving as a warning sign. A score of 25 or higher is considered severe and should be discussed with a healthcare professional.
Free Biomarker Test #5: Body Composition Assessment
The Science: Body composition, specifically the ratio of lean muscle mass to body fat, is a more crucial indicator of health and longevity than simply body weight. Both excessively high and excessively low body fat percentages can negatively impact health. Furthermore, muscle mass plays a vital role in metabolic health, strength, and resilience.
| Too much fat raises the risk for: | Too little muscle raises risk for: |
|---|---|
| Heart disease | Heart disease |
| High blood pressure | High blood pressure |
| Cancer | Cancer |
| Fatty liver disease | Stroke |
| Insulin resistance | Insulin resistance |
| Type 2 diabetes | Faster cellular aging |
| Inflammation | Inflammation |
| Joint distress | Depression and anxiety |
| Sleep apnea | Falls and loss of balance |
While gold-standard methods like underwater weighing, Bod Pod (air displacement), and DEXA (dual-energy X-ray absorptiometry) provide precise body composition data, they are not free. However, recent research has indicated that a simple, inexpensive tape measure can provide a comparably accurate estimate of body composition.
How to Measure It: To track your body fat percentage using a tape measure:
- Measure your waist circumference (at the narrowest point or just above the navel).
- Measure your hip circumference (at the widest part of the buttocks).
- Measure your neck circumference (just below the larynx).
Ensure the tape measure is snug but does not compress the skin. Once you have these measurements, along with your age, sex, height, and weight, you can input them into a free online body fat calculator (such as the Precision Nutrition Body Fat Calculator) to get an estimate.
Doctor-Approved Biomarker Tests: Essential Medical Insights
Beyond the free self-assessments, several critical biomarker tests are routinely performed as part of preventative medical care. While not always free, they are often covered by insurance and provide invaluable insights into long-term health risks.
Doctor-Approved Test #1: Comprehensive Blood Panel
The Science: Annual blood work, as recommended by primary care physicians, is fundamental for monitoring health trends. By tracking specific blood markers, clinicians can identify early indicators of conditions like type 2 diabetes or heart disease, both leading causes of premature mortality. Many of these blood markers are responsive to lifestyle changes, supplement protocols, or medications, often showing improvement within 6 to 12 weeks. This makes them practical tools for evaluating the effectiveness of health interventions.
How to Measure It: Consider having the following blood markers tested annually. Discuss your results with your healthcare professional, who may use these numbers, along with your blood pressure, to calculate your cardiovascular disease risk score.
| Blood marker | Optimal range |
|---|---|
| Total cholesterol | < 200 mg/dL* |
| LDL | < 100 mg/dL (without heart disease) |
| < 70 mg/dL (with history of heart attack/stroke) | |
| HDL | > 60 mg/dL |
| Triglycerides | < 150 mg/dL |
| Apolipoprotein B (Apo B) | < 133 mg/dL (males) |
| < 117 mg/dL (females) | |
| Lipoprotein (a) | < 30 mg/dL |
| C-reactive protein | < 2.0 mg/L** |
| Fasting glucose | < 100 mg/dL |
| Hemoglobin A1C | < 5.7% |
*Milligrams per deciliter of blood; **Milligrams per liter
Doctor-Approved Test #2: Bone Density Scan
The Science: Research on "super-agers" (individuals aged 90 and older who maintain exceptional health) consistently identifies strong bones as a defining characteristic. Bones are not inert structures; they are living organs that contribute to overall health and longevity by secreting substances like osteocalcin. This hormone plays a role in bone remodeling and is thought to influence diverse physiological processes, from ATP production in muscles to brain neurotransmitter regulation. The theory posits that as bone density declines, osteocalcin levels may drop, potentially contributing to age-related issues such as diabetes, sarcopenia (low muscle mass), and cognitive impairment, though much of this research is still in preclinical stages (e.g., mouse studies).
Beyond these potential hormonal roles, loss of bone density directly increases the risk of fractures, which can significantly elevate the risk of mortality for up to a decade post-injury. Monitoring bone health is particularly crucial for individuals in high-risk categories, including:
- Postmenopausal women
- Individuals with a family history of osteoporosis
- Those with certain medical conditions (e.g., celiac disease, inflammatory bowel disease)
- Individuals on long-term steroid therapy
- Those with low body weight or a history of eating disorders
How to Measure It: Dual-energy X-ray absorptiometry (DEXA) scans are the gold standard for measuring bone mineral density (BMD). These X-rays quantify the mineral content per square centimeter of bone. Insurance typically covers DEXA scans for individuals over 65 or those with documented risk factors for osteoporosis. Out-of-pocket costs average around $300.
Interpretation: DEXA results include a T-score, which compares your BMD to that of a healthy young adult with peak bone mass. A T-score between +1.0 and -1.0 indicates normal BMD. Scores below -1.0 suggest osteopenia (low BMD) or osteoporosis (porous bones prone to fracture), requiring further medical evaluation and potential intervention.
Advanced Commercial Bio Age Tests: Promises and Caveats
For those willing to invest financially, several advanced commercial tests promise deeper insights into biological aging. However, it is crucial to approach these with a critical perspective, understanding their limitations and the evolving nature of the science.
Important Caveats:
- Biological age variability: Biological age is not static. It can fluctuate due to periods of intense stress (accelerated aging) or focused recovery (slowing aging). Furthermore, different organs can age at different rates; a heart might be biologically older than the kidneys, for instance.
- Accuracy and reliability: Many commercial tests lack robust, independent scientific validation for their claims of precision in tracking individual changes or predicting longevity in healthy populations. Prioritize established healthy behaviors over isolated, unvalidated test results.
- Commercial bias: Be wary of companies that pair test results with aggressive sales pitches for proprietary and expensive supplement protocols. It is always best to discuss any test results with a trusted, independent healthcare professional.
Commercial Test #1: VO2 Max Testing
The Science: VO2 max, representing the maximum amount of oxygen your body can utilize during intense exercise, has long been a key metric for elite athletes. More recently, it has emerged as a powerful biomarker for overall health and the pace of aging, applicable to both athletes and non-athletes. High VO2 max is consistently associated with superior physical fitness and a significantly lower risk of developing cardiovascular disease, diabetes, cancer, and stroke.
A compelling 46-year observational study of 5,107 Danish men revealed that those with above-average VO2 max during middle age lived, on average, five years longer than their counterparts with below-average scores. Each unit increase in VO2 max correlated with a 45-day increase in longevity. The researchers even suggested that VO2 max might be a more accurate predictor of all-cause mortality than traditional risk factors like high cholesterol, obesity, high blood pressure, and insulin resistance. VO2 max can be considered a "canary in the coal mine" for your aging body. As we age, physiological changes—such as increased chest wall rigidity, weaker respiratory muscles, calcified blood vessels, reduced cardiac contractile force, lower maximum heart rate, and declining mitochondrial efficiency—all contribute to a natural decline in VO2 max, typically around 10 percent per decade after age 30.
How to Measure It:
- Lab-Based Testing (Gold Standard): The most accurate method involves wearing a metabolic mask and heart monitor while exercising to exhaustion (running or cycling) in a fitness lab. This measures expired carbon dioxide and oxygen intake, providing precise VO2 max and other metrics like lactate threshold and ventilatory thresholds. Costs typically range around $150.
- 1-Mile Walk Test: A more accessible method. Walk one mile on a flat surface (treadmill or track) at a brisk pace, wearing a heart rate monitor. Record your final heart rate and walk time. Use the following formula (or an online calculator) to estimate VO2 max:
132.853 – (0.0769 × Weight) – (0.3877 × Age) + (6.315 × Sex) – (3.2649 × Time) – (0.1565 × Heart rate)
(Sex: 1 for male, 0 for female) - Smartwatch Estimates: Many smartwatches provide VO2 max estimates based on workout data, sex, and age. While potentially over- or underestimating true VO2 max in very unfit or highly elite individuals, these devices are excellent for tracking personal trends over time. A decline after a period of inactivity, for example, is valuable information.
-
12-Minute Cooper Run Test: A validated method with approximately 90% correlation to lab-based measurements. Run as fast as you can on a flat surface for 12 minutes, then record the distance covered. Use one of these formulas (or an online calculator) to estimate VO2 max:
Distance in Miles Distance in Kilometers VO2 Max = (35.97 x distance in miles) – 11.29 (22.351 x distance in kilometers) – 11.288
Translating Data into Action: How to Positively Influence Your Biological Age
The information gleaned from biomarker aging tests should be viewed as objective data, not a moral judgment or an unalterable fate. The good news is that biological age is dynamic and responsive to interventions. You have the power to influence it. However, many individuals make two common mistakes when pursuing longevity-related lifestyle changes.
Mistake #1: Ignoring Evergreen, High-Impact Strategies
The pursuit of longevity often gets sidetracked by trendy, minimal-impact solutions, while the simple, "boring," and scientifically proven strategies are overlooked. These "big rock" health practices, when implemented consistently, are the true bedrock of a long and healthy life. We are referring to:
- Consuming a nutrient-dense diet: Emphasizing whole, unprocessed foods rich in fruits, vegetables, lean proteins, and healthy fats.
- Engaging in regular physical activity: A balanced routine incorporating strength training, cardiovascular exercise, and flexibility work.
- Prioritizing adequate and high-quality sleep: Aiming for 7-9 hours of restorative sleep per night.
- Practicing effective stress management techniques: Such as meditation, mindfulness, or spending time in nature.
- Cultivating strong social connections: Fostering meaningful relationships with family and friends.
- Abstaining from smoking and minimizing alcohol consumption.
- Maintaining proper hydration.
Thousands of studies consistently demonstrate that individuals who consistently adopt these high-impact strategies not only live longer but also experience a higher quality of life, characterized by greater strength, happiness, and a reduced likelihood of disability or pain in their later years. Yet, many gravitate towards the latest supplement or bio-hack, rather than addressing fundamental behavioral changes like quitting smoking or increasing daily physical activity. This often stems from the fact that big rock strategies require consistent effort and behavior modification, which is inherently more challenging than simply popping a pill. This is precisely why many individuals benefit from the structured support of a certified health coach, trained in the science of behavior change.
Mistake #2: Failing to Turn Data into Action
The allure of gathering personalized biomarker data can provide a sense of control and enlightenment. However, data in isolation, without subsequent behavioral change, is ultimately unproductive. Collecting biomarker data without altering your habits is akin to checking your reflection in a mirror, noticing spinach lodged between your teeth, and then simply walking away without removing it. The mirror check becomes worthwhile only when it prompts action.
Biomarker testing operates on the same principle. If you do not utilize your bio data to inform and drive behavior change, you are essentially wasting both time and resources. Consider your biomarker data as a valuable baseline or starting point. It provides an objective snapshot of your current physiological state. The true value lies in using this information to assess whether subsequent lifestyle changes, dietary adjustments, or medical interventions are effectively moving you closer to your overarching goal of living a longer, healthier, and more vibrant life. Regular re-testing then provides feedback on the efficacy of your efforts, allowing for continuous optimization of your health journey.
