Ever shake someone’s hand and immediately become envious of his or her grip strength? Aside from muttering to myself ‘darn that’s a firm grip’, I never really thought anything beyond that. I just generally pretend my hand doesn’t hurt and remind myself to avoid shaking that persons hand in the future.

But then starting in the mid 2000’s a series of studies started coming out linking grip strength with seemingly every health measure out there.

I’m not kidding. I remember reading papers on grip strength being associated with all-cause mortality, risk of falls and sarcopenia (muscle loss). All of these make sense to me. If you are weak, you are at a higher likelihood of being unhealthy, and also unable to catch yourself from falling which as we age is responsible for a high number of deaths.

But then I also remember reading studies linking weak grip with type 2 diabetes, trouble sleeping, and even cognitive issues like depression and sleep disturbance.

I remember thinking grip strength was in a ‘bubble’. The healthcare equivalent of the Dutch tulip bulb mania in the 1600’s.

But then more and more papers started coming out. In 2018, I wrote a short blog on grip strength after a very high quality paper was published in the British Medical Journal linking grip strength with all-cause mortality. I even put the blog out with the catchy title ‘one factor to live longer’.

Fast forward to 2023, and I am officially convinced that grip strength should be considered a ‘vital sign’ in your health, the same way your heart rate, blood pressure, height and weight are.

Literally everything we do requires adequate grip strength. Think about it. Open a door or a jar of food? Grip. Swing a golf club or pickleball racket? Grip. Go downstairs and slip while holding a banister? Better hope you have grip.

I went way down the grip strength rabbit hole for this blog after reading one shocking stat.

Anecdotally I feel like most people attend a gym now or do some sort of physical activity. It seems like a cultural norm now to workout, so as a society I assume we are generally stronger than our parents were.

Then I read that Americans actually have FAR WEAKER grip strength and WAY LESS muscle mass than even a single generation ago. In 1985, men aged 20-24 had an average right-handed grip strength of 121lbs. In 2015, that same age group was 101lbs. We as a society have lost about TWENTY PERCENT in our grip strength from just one generation ago.

Why was that alarming and what does it mean for our health future? I was shocked to find out.

To begin, we need to define if grip alone is a perfect predictor of strength.

I’ll save us all some time….. of course it isn’t!

Grip strength is measured using something called a dynamometer held with your elbow at 90 degrees. Essentially you just squeeze the thing as hard as you can and it lets you know your pounds or kilograms of force output. Some studies have shown that when you combine grip strength with a lower extremity test you get a much better proxy of overall strength BUT grip alone is pretty darn close and when used independently in research as a marker it works very well. Most importantly it’s simple to use and practical. A low cost one is under $100 and the test takes all of 10 seconds to perform. It’s also objective, meaning you can measure it over time to show improvement or deterioration. In short it checks a lot of my boxes for a great clinical test.

The issue I had previously with grip strength research is that it was retrospective in nature. As an example, researchers may look at people in the hospital that had falls and test their grip strength and then compare that to people in the general population that are the same age and gender and find out that those that fell had lower grip strength. That is a good association, but it does not in any way PREDICT that people with lower grip strength will indeed fall.

That has now changed.

There has now been a wide body of predictive research on grip strength proving its predictive ability for a number of conditions. The one that trumps all is your overall risk of death (all-cause mortality).

A 2019 review paper aptly titled “Grip strength: an indispensable biomarker for older adults” found there have been at least 3 high quality meta-analysis based on the predictive value of grip strength and all-cause mortality in the general population. They found that the pooled hazard ratios for mortality were as high as 1.79. In simplified terms that means that those with lower grip strength had roughly an 80% higher risk of death compared to those with ‘normal’ grip strength in the same age group. The pooled hazard ratio for each 5kg reduction in grip strength was 1.16, meaning you have a 16% higher chance of death for each 5kg reduction in grip.

That is huge. How huge? Another study showed that poor grip strength was actually a MORE POWERFUL predictor of cardiovascular mortality than systolic blood pressure!

Now how can that be? How could grip strength be more important as a predictor of cardiovascular death than blood pressure? It is highly likely that grip strength acts as a proxy for overall muscle strength and is a broad indicator of your general ‘robustness’ and health. In general, people with poor cardiovascular health likely avoid doing things throughout the day that promote good grip strength and therefore that grip weakens.

How do we know this is true?

Well yet another study showed that a 5kg decrease in grip was associated with an increased risk of cardiovascular disease with a hazard ratio of 5.98. That means that losing just 5kg of your grip strength increases your risk of cardiovascular disease by roughly 600%

600%! Let that settle in for a moment.

Next I wondered if maybe it was just a matter of body composition. Strength is very closely associated with absolute quantity of muscle mass (the larger your muscles the stronger you generally are). We know we lose muscle mass starting in our early 40’s (sigh) in a process called age related sarcopenia. We replace this muscle with fat.  So maybe our diminishing grip is due just to our loss of muscle mass?

Turns out it is not that simple. A 2006 study that used data from a large cohort called The Health, Aging and Body Composition (Health ABC) brought this assertion into question. This study specifically was designed to determine the role of body composition changes and subsequent risk of poor health outcomes including death as we age.

They looked at people aged 70-79 with no functional issues and followed them for 6 years taking CT and DEXA scans for body composition and grip strength and knee extension strength as measures of strength.

Not surprisingly they found that both quadriceps and grip strength were strongly correlated with mortality (the weaker you are the higher likelihood of death). For example, this is the chart of grip strength with survival. The numbers next to each line show where the person scored on grip strength. The declining slope of each line indicates the rate at which people passed away. You can see a straight relationship where people in the upper half had a much much much higher likelihood of survival at 6 years compared to those in the lowest 30%.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Now here was the interesting part. It turns out that body composition had very little correlation with mortality. Strength, as an independent variable was the predictive component.

Confused? I was. Essentially that means that despite losing muscle mass (and subsequently gaining adipose or fat mass), provided the person kept their grip strength up, their survival rate was unchanged!

A more recent 2017 study that I found that was much larger found the same thing in an English population that they followed for 8 years. They found that overall BMI is a poor predictor of mortality. Loss of muscle strength was again the greatest predictor of subsequent death.

So how do I know if I have good grip strength if I can’t come into The Proactive Athlete and use our dynamometer? Dr. Peter Attia, in his book Outlive, places a ton of weight in patients grip strength. He wants his patients to be in the top 2.5% of their age group for grip strength. The standard he likes to see is men in their 40’s should be able to carry the equivalent of their body weight for 1 minute in a farmer carry and for females it is 75%. He likes to see men dead hang from a pull up bar for 2 minutes in their 40’s and women for 90 seconds. He does slightly reduce the above numbers for each decade after 40.

Dave and I have been trying these tests and they are ‘humblingly difficult’ to say the least. So how do we improve our grip strength? Well lucky for you our Therapy Thursday video this week goes through a variety of our favourite grip strength exercises for you to try.

Once again I return to the old adage – “You can’t go wrong getting strong”.