Weak grip strength is a sign, not a cause, of poor health outcomes

An error of causality in this NY Times article

The Misunderstood Link Between Grip Strength and Mortality: A Causality Error in Popular Fitness Advice

I recently read a New York Times article titled "5 Exercises to Keep an Aging Body Strong and Fit". While the article offers practical and well-intentioned advice on staying active as we age, there's a critical flaw in how it presents research around grip strength. This issue reflects a broader misunderstanding that often creeps into health and fitness writing: confusing correlation with causation. Most people learn about this distinction at some point—whether in school, from reading, or through general awareness—and assume it’s a mistake that simply doesn’t happen anymore. Yet, if you look for it, you’ll see that this confusion is far more common than it should be—especially since, in theory, it shouldn’t happen at all.

The article highlights exercises like hanging from a pull-up bar, noting that increasing grip strength is linked to reduced all-cause and cardiovascular mortality. On the surface, this sounds motivating—improve your grip strength, and you'll live longer. But here's the problem: grip strength doesn’t cause longer life; it reflects overall health.

Photo by visuals on Unsplash

Grip Strength as a Biomarker, Not a Cause

Scientific research has shown a strong correlation between grip strength and longevity. Studies suggest that weaker grip strength is associated with higher risks of mortality, cardiovascular disease, and functional decline. However, the key word here is associated. This relationship doesn’t mean that improving grip strength itself directly reduces mortality risk. Rather, grip strength is a biomarker—a reflection of broader physical health, muscle mass, and systemic vitality.

Imagine your car's fuel gauge is low. Adding fuel addresses the real issue (lack of gas). But manipulating the gauge needle without adding fuel won't help you get farther. In the same way, low grip strength is like a warning light for underlying issues—frailty, poor nutrition, loss of muscle mass, or chronic illness—not the root cause of those problems.

The Danger of Misinterpreting Causality

The article’s implication that simply increasing grip strength through hanging exercises will lower mortality risk is a classic causality error. Improving grip strength may reflect gains in overall fitness, but targeting grip strength alone doesn’t tackle the deeper health concerns that the correlation points to.

In reality, systemic improvements—building overall muscle mass, improving cardiovascular health, and maintaining a balanced, nutritious diet—are likely the true drivers behind longevity and reduced disease risk. Grip strength improves along the way as a byproduct of better health, not as a direct cause of it.

Why This Matters

Why does this distinction matter? Because misinterpreting causality can lead to misguided health priorities. Someone might focus on grip strength exercises while neglecting other vital aspects of fitness, like cardiovascular conditioning or whole-body strength training. Misinterpreting the reality of causality, can lead to improper assumptions such as - if I don’t improve my BMI, then the exercise program I’m doing is not effective.

Exercise is a clear example of how correlation can be misleading. While lower BMI is often associated with better health, exercise improves outcomes like cardiovascular function, mental health, metabolic health, and quality of life—regardless of whether BMI changes. Assuming BMI is the cause of better health overlooks the direct effects of exercise. This highlights the danger of mistaking biomarkers for causes rather than indicators of underlying processes.

A Smarter Way to Think About Fitness and Longevity

The exercises recommended in the article—squats, Nordic walking, core training—are valuable because they contribute to overall systemic health. These movements improve cardiovascular function, boost muscle mass, enhance coordination, and increase flexibility—all factors that have well-documented effects on longevity and quality of life.

Grip strength should be viewed as a symptom of health rather than the cure. The real goal is to build a foundation of functional strength, endurance, balance, and flexibility that supports overall well-being.

Final Thoughts

It’s not that hanging from a pull-up bar is bad advice—it’s that the reasoning behind it needs refinement. Instead of chasing higher grip strength in isolation, aim for comprehensive fitness practices that nurture whole-body health. Your grip will likely improve naturally as a result—and with it, the health benefits the article was aiming for in the first place.

In the end, understanding the difference between correlation and causation isn’t just academic—it’s essential for making smart, effective choices about your health and fitness journey.