Hand grip strength is a major factor in predicting longevity and resilience to chronic disease. Let’s look at how to determine how strong you are and how this will give you insight into improving your chances of living longer.
Do you know how physically strong you are? Really, it’s a serious question. For your age and gender, what kind of strength do you have? Compared to other individuals at your particular season of life, is your strength above average, average, or below average?
It seems like a silly question, right? You can lift things and climb stairs without too much effort. Okay, you may not be able to open a jar of pickles as easily as Hillary can. But you can do things that require strength without too much difficulty.
However, do you know how strong you actually are? It’s not a silly question. It’s a deadly serious one. Here’s why.
A 2018 meta-analysis of over 2 million men and women showed that “Higher levels of upper- and lower-body muscular strength are associated with a lower risk of mortality in adult population, regardless of age and follow-up period.”
Did you pick that up? Regardless of age, your risk of dying is directly correlated to how strong you are. Or, to put it another way, the weaker you are, the higher risk you have of dying.
The above study is not an outlier. Numerous studies examining the correlation between muscle strength and mortality have been performed through the decades. And they all reveal the same thing. Stronger muscle strength means lower mortality.
This 2001 study followed 6,040 healthy men, aged 45 to 68 years old, at baseline for30 years and found that “in healthy middle-aged men, long-term mortality risk was associated with grip strength at baseline, independent of BMI.”
Another large study performed in 2008 followed 8,762 men, aged 20-80, for 18.9 years. The researchers discovered, “Muscular strength is inversely and independently associated with death from all causes and cancer in men, even after adjusting for cardiorespiratory fitness and other potential confounders.”
So, I think we can safely say that good muscle strength is a major factor in longevity. If you have good muscle strength, your chances of living longer improve.
Strength coach Mark Rippetoe interprets the data this way,
Strong people are harder to kill and are more useful in general.
Why exactly does good muscle strength correlate with lower all cause mortality?
Poor muscle mass is associated with insulin resistance
Researchers are not sure of exactly what the mechanism involved is that causes good muscle strength to correlate with lower all cause mortality. However, they do have a few theories.
First, skeletal muscle is the largest site for insulin?stimulated glucose utilization. When you consume a meal that contains glucose (from carbohydrates), that glucose will end up in your bloodstream.
Too much glucose in your bloodstream is toxic, so your body has to move it out. Most of that glucose is transported to your skeletal muscles and once there insulin moves it into your muscle cells. Most of the glucose entering muscle cells will be stored as glycogen which can be used for energy at a later date.
If this process in skeletal muscles is disrupted due to things like poor muscle quantity or quality, muscle inactivity or denervation, glucose homeostasis can be disrupted. This can lead to a condition known as insulin resistance. See here, here and here.
Consider some of these studies.
A 2017 study, composed of over 200,000 Korean men and women free of T2DM atbaseline and followed for 2.9 years, found,
In young and middle-aged Korean populations, RMM (relative muscle mass) was inversely associated with a risk of T2DM in a dose-response manner. RMM may play an independent role in the pathogenesis of T2DM and can be considered as a modifiable risk factor for this disease.
T2DM stands for type 2 diabetes.
Here is another notable finding from the study,
…the association between RMM and the risk of incident T2DM was stronger in the younger age group and premenopausal group even though the absolute incidence was higher in the older age group and postmenopausal group.
Notice younger people are not immune from the developing insulin resistance because of poor muscle mass.
Additionally, this recent study 13,620 participants showed that sarcopenia (loss of muscle mass) was an independent risk factor for MetS (metabolic syndrome) regardless of age, sex, obesity, DM (diabetes mellitus), HT (hypertension), DL (dyslipidemia), smoking, alcohol intake, and CRP (C-reactive protein) levels.
*I added the definitions of the abbreviations to make the information clearer.
See also here.
Again the risk of developing metabolic syndrome from poor muscle mass was not limited to elderly people.
Good muscle quality is important for healing
There is another theory researchers propose for the increased risk of mortality due to poor muscle mass.
During times of physical stress resulting from such things as severe infection, physical trauma, or advanced cancer the body needs increased amounts of amino acids for the healing process. Skeletal muscle is the reservoir where the body will need to get those amino acids.
If muscle quality or quantity is poor, then the amino acid pool might be diminished and the healing process retarded.
Muscle metabolism expert Dr. Robert R. Wolfe notes,
Whereas muscle mass plays a key role in recovery from critical illness or severe trauma, muscle strength and function is central to the recovery process. … Extensive losses of muscle mass, strength, and function during acute hospitalization causing sustained physical impairment were likely contributors to the prolonged recovery. If there is a preexisting deficiency of muscle mass before trauma, the acute loss of muscle mass and function may push an individual over a threshold that makes recovery of normal function unlikely to ever occur. For this reason, >50% of women older than 65 y who break a hip in a fall never walk again.
So the key here is to have good muscle strength before anything bad happens.
Okay, we’ve established that muscle strength is crucial for maintaining good health and longevity, but how do you know how well you’re doing?
Using strength tables
One way to access your strength is by using strength tables.
For example, one found at https://strengthlevel.com/strength-standards allows you to determine your strength according to different kinds of barbell lifts. Below is a strength standard for males and females corresponding to bench press. According to the site, these standards were determined after over 13,000,000 responses.
The chart also allows you to enter your gender and age.
Here’s the chart adjusted for my age (64).
As you can see, the standards decrease with age. This makes sense because generally people get weaker over time. However, this isn’t always true.
I started lifting weights 7 years ago after 25 years of suffering from chronic fatigue syndrome. At that time I could only bench press a 25 pound dumbbell. Now, at 64, I’m 20 pounds past the advanced standard.
Since these standards are for bench press, they give you a pretty fair assessment of chest and arm strength. There are standards for most major lifts.
The squat standard will give you a good idea of how strong your legs are. I’m still a little short of advanced so I know my legs are my weak link.
Okay, I can hear what you’re saying, “This is all well and good. But I don’t go to a gym, and I don’t lift weights so this isn’t really practical for me.”
I get it. If you don’t know how to lift weights, then don’t start until you know what you are doing.
But hold on.
There’s another way to test your strength, and it’s very easy to do and inexpensive. It may not give you a perfect indicator of your strength. However, it is used by doctors all over the world to assess strength in their patients.
You may have heard of hand grip strength (HGS).
Let’s take a look and see if a simple measurement of your HGS can predict possible future health outcomes.
Hand grip strength
A method widely used by physicians to assess strength is the measurement of hand grip strength (HGS) through the use of a dynamometer.
This is a Jamar dynamometer. It’s similar what most physicians would use for a HGS evaluation.
You grip the device and then squeeze as hard as you can. The measurement you attain can then be compared to a table of standards to see how your strength compares to the general population.
Though HGS measures the strength of muscles in your hand and forearm, it appears to be closely correlated with lower limb strength. So it is believed by health professionals to give a good overall assessment of total muscle strength.
Now, how is HGS associated with the overall health of your body and possible health in the future?
It appears from numerous studies, over decades of time, that HGS is closely correlated to overall mortality and mortality related to specific diseases.
Let’s take a look at some of these studies.
Hand grip strength studies
This recent study reviewed 8 different meta-analyses and reviews. It included over 23,000 participants.
After reviewing the data of the study, authors concluded that handgrip strength is a useful indicator for:
- General health status
- Early all-cause and cardiovascular mortality
- Future disability
*Soysal P, Hurst C, Demurtas J, et al. Handgrip strength and health outcomes: Umbrella review of systematic reviews with meta-analyses of observational studies.J Sport Health Sci2021;10:2905.
Another review of several meta-analyses and reviews investigating the relationship between HGS and mortality was conducted in 2018.
After reviewing 38 studies that included almost 2 million healthy men and women, researchers found:
- Higher levels of handgrip strength were associated with a reduced risk of all-cause mortality (HR=0.69; 95% CI, 0.64-0.74) compared with lower muscular strength
- The association was slightly higher in woman
- The results were independent of age and follow-up period
Also in 2018 a large United Kingdom study designed to investigate the association of grip strength with disease specific incidence and mortality was released. The study included 502,293 participants (54% women) aged 40-69 years. The mean follow up period was 7.1 years.
Again it was found, “Higher grip strength was associated with a lower risk of all cause mortality.”
But it also found that higher HGS was also associated with a lower incidence of mortality from cardiovascular disease, respiratory disease, chronic obstructive pulmonary disease, and all cancer and sub-types of cancer.
The Honolulu Heart Program
This particular study on HGS was begun in 1965. However, it is significant because of the duration of the study.
The study measured the HGS of 6,089 healthy men, aged 45-68 years old, and followed them for 25 years.
The authors of the study made the following conclusions:
- Among healthy 45 to 68-year-old men, hand grip strength was highly predictive of functional limitations and disability 25 years later.
- Good muscle strength in midlife may protect people from old age disability by providing a greater safety margin above the threshold of disability.
- Those in the lowest grip strength tertile had the greatest risk and those in the middle tertile had intermediate risk compared with those in the highest tertile.
But here is their really insightful finding,
Muscle strength is found to track over the life span: those who had higher grip strength during midlife remained stronger than others in old age. People with greater muscle strength during midlife are at a lower risk of becoming disabled because of their greater reserve of strength regardless of chronic conditions that may develop.
If you’re in that midlife age range, it’s critical to make sure your HGS is good to excellent. If it is, then you have an important asset in your quest to age well.
Okay, I think we can safely say that your HGS is a good predictor of how well you will age. If you have a poor HGS, the odds are you will age poorly. If you have an excellent HGS, your chances of becoming frail or disease prone in old age are greatly diminished.
Now, how do you measure your HGS?
Measuring your hand grip strength
Many physicians have a sophisticated HGS dynamometer, like the Jamar above, in their office.
However, there are many different makers of dynamometers for sale on Amazon. I can’t recommend any because I haven’t tried them. From the reviews they seem to do the job. See here.
You squeeze the device, get a read out, and then compare it to a chart that gives you an idea where you fall in accordance with your gender and age.
However, I want to make a comment about HGS standards. If we have a table of standards, where exactly do they come from?
Where do hand grip strength standards come from?
You could easily google hand grip strength standards and get a quick set of standards to judge your self by. But where do those standards come from. I like to have that kind of insight to make sure we get accurate information.
Below are three studies that present good data for HGS standards.
The Italian Study
In 2020 a study of 11,148 Italian individuals was conducted to determine normative HGS. The mean age of participants was 55.6 years (standard deviation: 11.5 years; range: 18–98 years), and 6382 (56%) were women.
These are the normative standards discovered.
Normative values for handgrip strength (kg) in men, stratified by age
Normative values for handgrip strength (kg) in women, stratified by age
As you can see from the charts, HGS peaks in early adulthood, is maintained for a few decades, and then starts to drop off noticeably. This makes sense because we know that as we grow older muscle mass declines. It’s a normal part of aging.
However, some people can have an accelerated loss of muscle due to health issues or a sedentary lifestyle. This is known as age-related sarcopenia.
See my article here: How I’m beating sarcopenia with weight training.
On the other hand, some people may actually improve muscle quality or gain mass even into their eighties by the use of a well structured strength training program. More on that later.
Here are standards from another study.
In 2016, a survey similar to the one above was performed throughout Germany. It consisted of a random sample of the 11,790 individuals, aged 17 – 90. This study however, added height as a category.
These are the standards they came up with.Normative Reference Values of Handgrip Strength for German Men
Normative Reference Values of Handgrip Strength for German Women
In this study, the researchers noted that there is a 1 standard deviation drop in strength for men in the 65 to 69 category. This is about a 10 KG drop when measured with the grip device.
They ultimately concluded, “Using this simple approach, a weak grip was defined to start below 33 kg for men and below 21 kg for women.”
The researcher continued, “Relaxing the definition, using a cut-off at 1 SD below the sex-specific peak mean values, weak grip would be defined to start already below 44 kg for men and 28 kg for women.”
The researchers concluded that according to this definition, “around 20% of 50–54 year olds would be classified as weak, about half of the population aged 65–69, and about three quarters of the population aged 75–79. The vast majority of octogenarians have a weak grip (88%) according to this alternative definition.”
Notice that the standards were close to the Italian standards.
Finally, a British study.
British Study standards
A 2014 British study combined 60,803 observations from 49,964 participants (26,687 female), aged 4 to 90, of 12 general population studies.
Their objective was to produce cross-sectional centile values for grip strength across the life course. And to investigate the prevalence of weak grip, defined as strength at least 2.5 SDs below the gender-specific peak mean. More on that in a moment.
Here are their results.Normative values for grip strength, stratified by gender
The question here, though, is according to these standards, what is considered a weak grip? The study authors propose that for women a weak hand grip would be equivalent to 19 kg in females and 32 kg in males. They base this on a 2.5 standard deviation from mean peak HGS.
For example, a 55 year old female with a HGS of 19 kg would be considered to have a weak HGS, and the chart would also place her in the lowest centile.
The authors do state that other studies have found a higher cutoff for weak grip. Indeed, the German study above had a weak HGS at 21kg for women and 33kg for men. The German study also stated that a weak HGS at slightly higher values would not be totally unacceptable.
Observations From The Italian, German And British Charts
Okay, so how do we use this information? Let’s say you are a 55 year old female with a HGS 22. According to the Italian chart your HGS would be weaker than the mean population and you would be approaching the 25th percentile. The German chart has you approaching a higher risk category.
The British standard would also show that you were in a lower centile of HGS. Thus, you should perhaps be concerned that this result indicates that you are at risk for a poorer health outcome long term.
If you are a 50 year old male with a HGS of 45 according to the above standards charts, your HGS would be about average. However, if for some reason your strength diminished suddenly you would be in danger of approaching riskier categories for HGS and possibly increased odds of mortality.
The bottom line
Hand grip strength is now a standard procedure used to predict future poor health outcomes and mortality. The good thing is that you can purchase a dynamometer inexpensively and test yourself at home.
If you have a good HGS, that’s great. But be aware that your strength probably will decrease over time. Over a long enough time span, everyone’s strength goes to zero.
If your HGS is good, the key is to maintain it or to increase it. If it’s not as good as you want it to be, then you’ll want to increase it to good levels.
Is that even possible?
Twenty years ago I went to a naturopathic doctor to see if he had some insights to help me heal from severe chronic fatigue syndrome. As part of his examination, he had me squeeze a handle that was attached to a gauge.
After the test, he looked at Barbara and said, “When your husband says he doesn’t feel good, he’s not lying. His strength is poor.”
He probably was measuring my HGS.
Now, after healing from CFS and employing an excellent strength program for 7 years, I can deadlift a 300 pound barbell in my hands. You need a pretty good HGS to do that.
So you can improve your HGS.
The best way to do it if you are healthy is through strength training.
See my article here on how I started strength training.
Every adult can do it. Even if you’re 80 years old or even 100. https://www.youtube.com/embed/L6QM_-V86gQ
So have your physician test your HGS or do it yourself. Remember this though the more strength you have, and you can increase it, the greater your chances of living a healthy longer life.
God bless and have a great week!
This article first appeared on The Glutenfreehomestead.com
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