Muscular Strength & Mortality

Time to Read: ~6 Minutes

From the Archives: This is an original (pre-2021) SFF blog post that has been reposted with updated information.

Take Home Points:

Is it healthier to be stronger? In a general sense, yes, because the stronger you are, the less likely you are to hurt yourself doing basic activities like lifting, bending, and sitting. Being stronger also makes it less likely you will fall and hurt yourself (particularly when you are older). But what about beyond these external interactions, can being stronger extend your age of death?

Study Rationale

A study from Ortega et al., 2012 examined whether being stronger as an adolescent affected one’s overall health as indicated by their ultimate age of death (mortality). The authors were particularly interested in premature mortality, which they defined as death before 55 years of age. What’s great about this study is it literally includes over a million participants (though a limitation is they are all male) and tracks the same individuals until death. The assessment of strength was based on knee extension strength, handgrip strength, and elbow flexion strength.

 

Study Findings

By including all causes of death (heart disease, stroke, cancer, suicide, and other), the authors found that higher levels of muscular strength were associated with a lower risk of premature death, particularly if using knee extension and handgrip as the strength measures. Interestingly, the authors were able to separate out variation in body mass index (BMI), generally an estimation of how fat an individual is, and found that regardless of BMI, the relationship of higher muscular strength to reduced premature death held. Thus adolescents with low body fat and ones with high body fat all demonstrated reduced premature death if they had increased muscular strength. In terms of the specific causes of death, increased muscular strength was associated with decreased cardiovascular death, decreased suicide death, but not decreased deaths due to cancer (which was better predicted by an individual’s BMI).

What’s important to remember about this study is that it is a study of associations, more specifically, given that hazard ratios are used, it is just a statistical assessment of the chance or likelihood of death in one group versus another (i.e., low muscular strength to high muscular strength). Studies like this attempt to control for other variables (e.g., BMI, blood pressure) and statistically remove them, but the manipulation is just that, a mathematical adjustment. Further, not all variables can be considered in studies like this and some may “tag along” with the variable of interest. As an example, one might invoke the anecdote about how in the summer violent crimes increase in association with increased ice cream sales, thus the two may be related in some way. Here, though, an entirely separate variable (heat) affects both in different ways and there is no actual relationship between ice cream sales and violent crimes, even though collecting data on the two might suggest there is. This example is an important one in that it emphasizes how problematic it can be if we do not think about other relevant variables.

In terms of this study, perhaps all the stronger individuals had a unique exercise regimen they used, such that a systemic hormonal response was present. Perhaps the hormone profile built muscular strength through the growth hormone pathway and perhaps it minimized strokes through the nitrous oxide pathway. The end result could be just what was measured in the study – muscular strength is associated with reduced deaths due to stroke. Does this invalidate the study? No, but it would mean the two are associated by  one or more other factors. When studies like this are conducted, the tendency is for the authors and readers to see the data as suggesting that one variable (muscular strength) causes the other (reductions in stroke). Of course the paper never uses the word cause, but it’s in the the back of everyone’s mind – particularly if you’re a die-hard weight-lifter who wants to feel like those massive muscles are protecting you from a stroke.

New Studies Since 2014

Although the aforementioned study is correlative in nature, since 2014, there have been many studies examining the relationship between muscular strength and mortality, all of which have suggested similar protective effects by being strong. Below are just a few of these studies:

A study in 2018 of 4000+ adults 50 years of age or older found that all-cause mortality was significantly higher among individuals with low muscle strength, whether they had low muscle mass or not (PMID: 28991040).

In a 38 study 2018 meta analysis, higher levels of handgrip strength were associated with a reduced risk of all-cause mortality compared with lower muscular strength, with a slightly stronger association in women than men. For muscular strength assessed by knee extension strength test, those with higher strength levels had a 14% lower risk of death compared with adults with lower muscular strength (PMID: 29425700).

A 2025 meta analysis of 42 studies found that significant reductions in all-cause mortality was associated with increased strength. In addition, muscle strength was associated with an 8-46% reduced risk of all-cause mortality in patients with advanced cancer stages (PMID: 39837589).

Final Thoughts

Numerous studies have linked increased muscular strength to reductions in mortality. As noted, the studies are all correlative in nature, and therefore do not prove causality. However, given that 1) studies keep confirming this positive association of increased strength and decreased mortality and 2) there are many other benefits to increased strength, it's a good idea that all individuals conduct regular strength training. The worst case scenario is that doing so will improve your quality of life, the best case scenario is that it may also extend your mortality.