And why your handshake may reveal more about your health than your blood pressure

Indicators of Long-Term Health and Longevity

In this next longevity blog, I’m excited to delve into phenotypic biomarkers of healthy aging. These markers are observable physical traits linked to aging, distinct from molecular biomarkers like telomere length, which focus on cellular or genetic changes. I’ve been particularly intrigued by how these well-studied phenotypic markers translate into healthier and potentially longer lifespan. While genetics, environment, education, and socioeconomic factors play a significant role in longevity, certain predictors of healthy aging stand out:

• Grip strength
• Leg strength
• VO2 Max
• Balance

Let’s explore these indicators further, as they combine strength, muscle mass, and VO2 Max. Essentially, physical fitness designed to keep the body strong and well-functional into old age. As such, there are the three pillars of physical longevity (source: Neuromuscular and Sports Injury Clinic):

• Strength – The Foundation of Longevity
• Muscle Mass – The Metabolic Safety Net
• VO2 Max – The Key to Cardiovascular Health

Strong performance across the four indicators, handgrip strength, leg strength, VO2 Max, and balance is crucial for long-term health and longevity. Using all this information, I created the Longevity Quadrant, as depicted in Figure 1, with the predictors of healthy aging.

The good news is that we can take proactive steps to improve these predictors and enhance overall health!

Figure 1: The Longevity Quadrant with Predictors of healthy aging.

“Your strength, muscle mass, and VO₂ Max define how long and well you live!”

With this blog I explore why handgrip strength is such a practical and scalable biomarker (i.e., indicator) of healthy aging and how we can improve it.

Grip Test: The Simplest Test for Lifelong Vitality

Grip Strength Measurement

Grip strength is typically measured using a Dynamometer Test, with healthy ranges generally being 32.8 ± 10.5 kg for men and 21.9 ± 8.1 kg for women. Another effective method is the Hanging Time Test, where adults should aim to hang from a pull-up bar for at least one minute.

There are five common measurements of grip strength:

1. Average of handgrip strength (HGS)
2. Maximum of grip strength (MGS)
3. HGS/body mass index (BMI)
4. HGS/height (HT)
5. MGS/weight

Additionally, there are three indicators of low grip strength:

1. Low reference grip strength
2. Lowest 20% grip strength
3. Low grip strength in sarcopenia

Note: Sarcopenia is defined as loss of muscle tissue as a natural part of the aging process

“Studies have consistently shown that low grip strength is associated with an increased risk of mortality, a higher burden of chronic diseases, and faster rate of functional decline.”

The Broader Health Significance of Handgrip Strength

Emerging science suggests that handgrip strength is a powerful indicator, or proxy, for much more than just hand and forearm strength. It reflects your body’s ability to maintain muscle mass and function, and it’s a significant indicator of metabolic resilience, brain health, and even longevity.

It’s important to note that grip strength not only reflects the strength of your hand and forearm muscle, but also the body’s ability to maintain muscle mass, strength, and function as a whole. But, strengthening your grip alone doesn’t directly extend your life, as it does not improve overall muscle function and metabolic health.

A decline in grip strength can signal muscle loss (sarcopenia), reduced neuromuscular function, and metabolic decline. These factors can increase the risk of cardiovascular disease, frailty, and early mortality. A study by Chai and Fan (2024) indicates that absolute grip strength (HGS, MGS) is an optimal predictor of all-cause mortality, followed by HGS/HT. Maintaining adequate level handgrip strength appears beneficial in reducing mortality risk.

Research from the 2011-2014 National Health and Nutrition Examination Survey (NHANES) data and National Death Index (NDI) data supports the idea that absolute and relative grip strength measurements are effective of mortality risk. However, further research is needed to explore the interaction effect of age and sex, as current data shows varying results across different studies.

“Grip strength is not just about hand strength, it also reflects overall muscle mass and strength, which is crucial for metabolic health, especially for aging individuals.”

Low Grip Strength as a Marker for Higher Mortality

Research indicates that grip strength is inversely associated with all-cause mortality, cardiovascular mortality, non-cardiovascular mortality, myocardial infarction, and stroke (Leong et al., 2015). In fact, grip strength was found to be a stronger predictor of all-cause and cardiovascular mortality than systolic blood pressure. But it is also worth noting that there is no significant association between grip strength and incident diabetes, risk of hospital admission for pneumonia or COPD, injury from falls, or fractures (Leong et al., 2015). Additionally, while a positive association between the risk of cancer and grip strength was observed in high-income countries, this was not found in middle-income and low-income countries (Leong et al., 2015). An earlier study from 1999 even showed the midlife handgrip strength can predict old-age disability (Rantanen et al., 1999).

Handgrip Strength and Metabolic Health

Muscles are vital in regulating metabolism, particularly in terms of glucose uptake and insulin sensitivity. Consequently, muscle mass and strength are closely associated with better metabolic health. Research indicates that grip strength, when considered alongside other factors (e.g., weight, BMI, body fat percentage, waist circumference, blood lipid profile, blood glucose, and blood pressure), can be useful tool in detecting metabolic syndrome (MetS) (Garcia-Hermoso et al., 2020). Specifically, there is an inverse relationship between handgrip strength and MetS, meaning lower handgrip strength, often adjusted for body weight, can serve as a screening tool to identify individuals who might be at a greater risk of developing MetS. It’s important to note that handgrip strength is not a definitive predictor of MetS and should always be used in conjunction with other risk factors and diagnostic criteria. Additionally, these cut-off values can differ based on factors such as age, sex, and ethnicity (Garcia-Hermoso et al., 2020). 

From Handgrip to Glucose: The Strength-Insulin Connection

Reduced grip strength can also be a sign of insulin resistance, a condition where the body’s cells don’t respond effectively to insulin, which can increase the risk of developing type 2 diabetes (Ojulariy et al., 2025).

The 2025 study by Ojulariy and colleagues in Nigeria explored the relationship between handgrip strength (HGS), insulin sensitivity, and β-cell function in healthy, non-diabetic young adults. The study, involving 158 participants, assessed both absolute and relative HGS along with key metabolic markers such as fasting glucose, insulin levels, and calculated HOMA-IR and HOMA-β indices. The researchers found strong, statistically significant associations between HGS and both insulin sensitivity and β-cell function, particularly in male participants. These correlations were less pronounced in females, which may be due to physiological or lifestyle differences. This study suggests that HGS may serve as a simple, non-invasive screening tool for evaluating metabolic health and identifying early risks of insulin resistance. Further research in larger and more diverse populations is needed to confirm these findings (Ojulari et al., 2025).

The Many Drivers Behind Handgrip Strength

The recently published study by Wu and Li (2025) addresses the need for a practical tool to assess handgrip strength in older adults. While many studies have examined factors influencing handgrip strength, this research uniquely integrates multiple factors into a predictive nomogram (Note: A nomogram is a graphical calculation tool used to estimate outcomes based on specific clinical parameters representing the relationship between three or more variables). Wu and Li (2025) developed and validated this nomogram using data from the first wave (2011) and the fifth wave (2020) of the China Health and Retirement Longitudinal Study (CHARLS). Their logistic regression model identified key predictors of low handgrip strength, including:

• Age
• Chronic disease history
• Marital status
• Lifestyle
• Education
• BMI
• Activities of daily living
• Glycated hemoglobin.

While age-related sarcopenia is a significant contributor to declining strength, other critical factors include nutritional status, cognitive function, chronic disease burden, and lifestyle. Sarcopenia, characterized by a decrease in muscle mass and strength, typically begins around the third or fourth decade of life and accelerates after age 50 (Vishaya et al., 2024). Inadequate protein intake, is a notable risk factor for sarcopenia, with malnourished individuals often exhibiting lower handgrip strength (Pieterse et al., 2002). Maintaining good nutritional status, especially sufficient protein intake, is crucial for preserving muscle health as we age. Interestingly, sarcopenia has also been linked to cognitive impairment, suggesting a connection between muscle health and brain function (Scisciola et al., 2021; Larsson et al., 2017). 

My prior blog, A Look at Human Longevity & Life Expectancy, discussed how various chronic diseases, such as Type 2 diabetes, cardiovascular disease, stroke, chronic kidney disease, and some cancers, are associated with aging. The presence of multiple chronic diseases (multimorbidity) further accelerates this decline which is also associated with a decline in handgrip strength (Xia et al., 2024).

Finally, a sedentary lifestyle and physical inactivity are major contributing factors to sarcopenia and reduced handgrip strength. Adopting a healthy lifestyle (Bartels et al., 2019), including regular exercise and a balanced diet, is essential to mitigate the impact of sarcopenia and preserve handgrip strength as we age. 

Age and Gender Patterns for Handgrip Strength

Handgrip strength, which is treated as a continuous variable, approximately follows a normal distribution as shown in Figure 2 (Wu & Li, 2025). When measured using a handheld dynamometer, the average handgrip strength for males is 32.8 ± 10.5 kg, and for females, it is 21.9 ± 8.1 kg (Fig. 1A). The age-stratified analysis also revealed that handgrip strength gradually declines with age. Notably, individuals aged 80 and above showing a 35% decrease in average handgrip strength when compared to those aged 45–60 years (Fig. 1B).

Figure 2: Gender distribution and age-related analysis of grip strength (source: Wu & Li, 2025).

Linking Health Metrices to Handgrip Strength Performance

Insights from the work by Wu & Li (2025) results in the relationship patterns between primary predictors and handgrip strength, which are summarized in Figure 3.

Some key highlights include:

1. Age: There is a significant negative linear correlation between age and handgrip strength; for every 10-year increase in age, handgrip strength decreases by approximately 4.5 kg (see Figure 2-A).
2. BMI: Handgrip strength and BMI have an inverted U-shaped relationship, with the strongest handgrip strength observed in participants with a BMI was between 23.8 and 26.4 kg/m² (see Figure 2-B).
3. Cognitive function: A moderate positive correlation exists between total cognitive scores and handgrip strength, showing a 2.1 kg increase in handgrip strength for every 5-point increase in cognitive score (see Figure 2-C).
4. Education: Higher education levels are associated with significantly greater average handgrip strength. Individuals with a university degree or higher have an average handgrip strength approximately 8.5 kg greater than those with only primary school education or lower (see Figure 2-D).
5. Chronic disease: Comparison of handgrip strength among individuals with and without various chronic diseases revealed show significant negative correlations with stroke, heart disease, and cancer (not shown).
6. Biochemical Indicators: Hemoglobin and prealbumin are positively correlated with handgrip strength, while C-reactive protein shows a negative correlated, suggesting that nutritional status and inflammation levels are key factors affecting handgrip strength (not shown).

Figure 3: Analysis of the relationship between handgrip strength and the main predictors (source: Wu & Li, 2025).

Clearly, age is a significant predictor of low handgrip strength, which aligns with age-related sarcopenia and its impact on overall muscle strength. Notably, age 65 appears to be a critical turning point for muscle function decline. However, it is important to consider factors beyond age when assessing handgrip strength, as many other factors also show significant effects and correlation. A total of 12 key predictors have been identified, as mentioned above. In addition to age, a history of chronic diseases and limitations in activities of daily living are major risk factors for reduced handgrip strength. To mitigate these risks, it is important to aspire:

• Higher education: while not directly influenceable, it’s a recognized factor.
• An appropriate BMI range: maintaining a healthy body mass index.
• Regular physical activity: This includes consistent exercise, moderate intensity activity, resistance training, aerobic exercise.

Certainly, the protective role of regular exercise is well-established, and resistance training and aerobic exercise is highly recommended for older adults to alleviate muscle function decline.

The Link Between Mitochondrial Function and Muscle Strength

There is a crucial link between mitochondrial function and muscle strength, especially as it relates to key predictors of life expectancy like handgrip test, leg strength, VO2 Max, and balance.

Muscle mass plays a central role in these predictors. Hand grip strength and leg strength are directly correlated with muscle mass and the efficiency of mitochondria in our cells. VO2 Max, which measures the maximum oxygen your body can utilize during exercise, is also closely tied to muscle mass.

Mitochondria, the Powerhouses of our Cells

Mitochondria, often called the “powerhouses” of our cells, convert oxygen and nutrients into energy (ATP). A higher VO2 max indicates denser and more efficient mitochondria in muscles, leading to greater energy production, better endurance, and fatigue resistance. For handgrip and leg strength, mitochondria supply the energy needed for muscle contractions and overall function. Research, such as that by Mau and team (2023), highlights a direct link between mitochondrial function and both handgrip and leg strength, with mitochondrial capacity improving leg power and physical performance in older adults.

Mitochondrial damage or dysfunction can lead to skeletal muscle atrophy, a very complex mechanisms, involving a sophisticated network of cellular signaling pathways and processes that are still not fully understood. While some biological mechanisms underlying age-related changes in muscle and physical function are still being explored, it’s clear that targeting and prolonging mitochondrial function through focused exercise, nutritional and lifestyle interventions, and even therapeutics are essential methods for effectively preventing age-related disability and physical decline (Mau et al., 2023).

VO2 Max, the Direct Link to the Health and Abundance of Mitochondria within Muscle Cells

VO2 max is a strong indicator of overall fitness and health due to its direct link to the health and abundance of mitochondria within muscle cells. While a direct causal link between balance and mitochondria isn’t yet established, mitochondrial health significantly impacts overall physical function, which indirectly affects balance. Interestingly, mitochondrial dysfunction in older adults has been linked to declines in gait stability and muscle function, both essential for maintaining balance. Strengthening muscles through exercise can improve mitochondrial health, contributing to better balance and reduced fall risk.

The Master Regulator PGC-1α Regulates the Mitochondrial Lifecycle

It’s also worth noting that decreased physical activity can negatively affect mitochondrial capacity (Ringholm et al., 2011), whereas exercise stimulates mitochondrial biogenesis and function by increasing the master regulator PGC-1α, which regulates the mitochondrial lifecycle and ROS stress response (Abu Shelbayeh et al., 2023). In mammals, fasting, exercise, and cold are associated with an increase in PGC-1α levels (Puigserver & Spiegelman, 2002; Chabi et al., 2005; Puigserver et al., 1998). A nice overview of the post-transcriptional control of PGC-1α is depicted in Figure 4. PGC-1α (Abu Shelbayeh et al., 2023) which subsequently upregulates respiratory gene expression in the mitochondria (Finck & Kelly, 2006). As older adults tend to be more inactive, their functional fitness decreases (Sousa et al., 2020). Though, distinguishing the extent to which chronological age versus physical inactivity contributes to the decline in mitochondrial function and muscle health during aging remains an area of active research.

Figure 4: Overview of the post-transcriptional control of PGC-1α (source: Abu Shelbayeh et al., 2023).

In summary, mitochondrial health is fundamental to overall physical function, influencing cardiovascular fitness, muscle strength, and indirectly, balance. Exercise, especially endurance and resistance training, can stimulate mitochondrial adaptations, leading to improved efficiency and increased numbers of mitochondria. Pulling this all together, one can say that…

“…these seemingly disparate tests (handgrip strength, leg strength, VO2 Max, and balance) are all indirectly measuring the effectiveness of the body’s mitochondrial ‘powerhouses.'”

Research Data

Again, some interesting data that we all have access to and that I am sharing here with this post.

Data Source	Details
National Health and Nutrition Examination Survey (NHANES)	o National health survey data, including health exams and laboratory tests
National Death Index	o Connects public health and medical researchers with U.S. death records. o Links researcher’s data to death certificate information for their study subjects.
China Health and Retirement Lognitudinal Study (CHARLS)	o The China Health and Retirement Longitudinal Study (CHARLS) collects high quality nationally representative sample of Chinese residents ages 45 and older to serve the needs of scientific research on the elderly. o The baseline national wave of CHARLS is being fielded in 2011 and includes about 10,000 households and 17,500 individuals in 150 counties/districts and 450 villages/resident committees.  o The sample covered 150 counties and districts across 28 provinces, as well as 450 villages, ultimately including around 10,000 households and over 17,000 individuals.

Table 1: Various databases referenced in this blog.

How to Improve Handgrip Strength

To effectively improve handgrip strength, and leg strength for the same matter, it’s beneficial to focus on compound movements. These exercises engage multiple muscle groups and joints simultaneously, extending beyond just the hands and forearms to include larger muscle groups. This approach is efficient for training and helps promote overall strength, muscle growth, and functional movement. By working all muscle groups, you can achieve improved body coordination and functionality. Combining this type of resistance training with endurance training can also stimulate mitochondrial adaptations, which leads to improved efficiency and an increased number of mitochondria.

Note: it’s important to remember that before starting any rigorous exercise plan, especially at an older age, one should consult a physician to ensure it’s safe.

Conclusion

It’s clear that age itself contributes to a natural decline in muscle mass and strength. Sarcopenia, which can begin as early as age 30 (with the rate of decline accelerating between ages 40 and 60), can have a debilitating and potentially irreversible effects if not addressed. Beyond aging, other factors, such as chronic diseases (e.g., arthritis, diabetes, nerve injuries) and certain medications (e.g., statins, corticosteroids), can also impair muscle strength and recovery, leading to weaker handgrip. For chronic diseases influenced by lifestyle, it’s crucial to make necessary changes.

Several lifestyle factors significantly influence handgrip strength, particularly as we age. To maintain or improve it, it’s essential to incorporate regular exercise (both endurance and resistance training), ensure adequate protein intake (Note: adequate protein intake is crucial for maintaining muscle mass and function, especially as we age and adequate intake along with exercise can help slow down or even prevent sarcopenia), vitamin D consumption (Note: vitamin D plays a crucial role in maintaining and improving muscle health, impacting muscle growth, strength, and overall function), and creatine intake (Note: creatine intake does not build muscle, but may offset age-related sarcopenia), follow a nutrient-rich anti-inflammatory diet, prioritize quality sleep, manage stress effectively, and avoid smoking and excessive alcohol consumption. Basically, the usual!

“Aging may be inevitable, but weakness doesn’t have to be. Strength is built and preserved through daily choices: move often, fuel wisely, rest deeply, and protect your future self.”

References

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