Strength isn’t just useful when helping a friend move or defending an arm-wrestling title at family dinner. Research shows that muscle is a key component to healthy aging. It can quite literally add years to your life.¹ 

This is a concept known as “strengthspan.” It’s the length of time you’re able to maintain functional strength over the course of your life.  

Researchers are increasingly paying close attention to strengthspan. It’s gaining momentum as a serious measure of life quality, right next to lifespan and healthspan.

Unlike lifespan and healthspan, strengthspan emphasizes muscle mass, a key (and to some, surprising) measure of health that you can control directly. 

Muscle, which researchers often measure with a grip strength test, “is probably one of the strongest predictors of lifespan and healthspan,” says Gregory Tranah, Ph.D., professor of epidemiology at UCSF and Sutter Health.⁴

“It’s not about gripping specifically—you don’t just squeeze a tennis ball and live forever,” says Tranah. “It’s that peripheral muscle groups are strong indicators for overall strength and health.”

By maintaining muscle throughout your life, you improve strengthspan. And that means staying active, mobile, and self-sufficient well into old age.

How strength lengthens and improves your life

For many older adults, sarcopenia makes life challenging. This is the muscle loss that occurs naturally with age.

After age 30, most people lose as much as 3% to 5% of total muscle mass per decade, and over time, that increases the risk of falls and frailty.⁵ 

But if you can build muscle as fast as you lose it, you can maintain your independence. In a study of adults over 65, every 22-pound increase in grip strength boosted the chances of staying functionally independent—like being able to cook, clean, and care for yourself—by 39%.⁶

And the benefits of strength go beyond daily tasks. An analysis of more than 3,600 older adults found that greater muscle mass was linked to a 20% lower risk of death from all causes, making it a better predictor of longevity than even body mass index (BMI).⁷ 

Given this, it comes as no surprise that research from the Honolulu Heart Program determined handgrip strength to be a reliable predictor of longevity:⁸

As it turns out, the functional benefits of muscle strength ripple through to just about every part of your body. 

• Denser bones: People who fracture a hip after 50 have a 24% risk of dying within the following year.⁹ But older adults who start strength training show improvements in bone mineral density, which helps prevent osteoporosis and fractures.¹⁰
  
  
• Better cardiovascular health: Strength is linked to heart health. In a study out of the UK, stronger people had signs of healthier heart performance and less thickening of heart muscle—both of which are associated with lower risk of heart attack and other cardiac events.¹¹
  
  
• Stronger brain: A meta-analysis of 15 long-term studies revealed that stronger people had half the risk of cognitive decline and a lower risk of various types of dementia, including Alzheimer’s disease.¹²
  
  
• Better mental health: A study following 115,000 older adults found that strength was associated with a lower risk of depression—even when adjusted for factors like physical activity level.¹³

How to measure strengthspan

In the lab, grip strength is the most common way researchers measure strength. And it’s relatively easy to do: You can find measuring tools called handgrip dynamometers for about $20 online. 

Grip is also a good proxy for overall strength. “If you develop overall strength by pushing, pulling, lifting, or carrying, you’re also using grip,” says Zachary Walston, PT, DPT, OCS, a certified specialist in orthopedic physical therapy.¹⁴

For both men and women, grip strength typically peaks in your 30s and declines with age.¹⁵

But grip strength isn’t the only measure of muscle. “Quad strength is another strong indicator,” says Walston. This can be measured with squats or leg presses. 

For a simple test, sit in a chair and see how many times you can go from standing to sitting in 30 seconds. The more you can do, the better. 

At age 60, you should be able to stand at least 14 times if you’re a man and 12 times if you’re a woman, according to the CDC. This number decreases with age.¹⁶ 

In addition to measuring strength directly, it’s helpful to look at your body’s capacity to build muscle. Hormones such as cortisol and testosterone play a critical role here. “These hormones are critical for muscle health and building muscle,” says Tranah. 

If you're an InsideTracker member, you can test these hormones directly with a $99 fitness blood test.

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How to build your strength

“The only way to build or maintain muscle is to train,” says Walston “What you eat helps too, but without training, strength disappears.” 

And here’s some good news: It’s never too late to start training. Whether you’re a regular gym goer or you haven’t touched a weight in years, experts agree you can improve your strength. “Strength training is for everybody,” says Tranah. 

To prove it, researchers followed a group of 90-year-olds. With 12 weeks of strength training, the subjects improved their walking speed, balance, fall risk, and muscle power.¹⁷ 


» Walking Backwards—Is It a Leap Forward for Healthy Aging?

The specifics of your training will look different depending on your age and fitness level. But when it comes to choosing a routine, “The best one is the one that you’ll stick with,” says Watson. Resistance bands, bodyweight movements (think squats and pushups), weight machines, and free weights all fit the bill. 

To get started, Watson recommends two 20-minute strength sessions per week. At each session, complete 8 to 10 total sets, focusing on different muscle groups. “To build strength and muscle, push close to failure—whether that’s four or 30 reps,” he adds. 

No matter what your age, when you start a fitness routine, the best practice is to start gradually. Listen to your body. As you get more comfortable, you can increase the intensity. 

“Take medical conditions into account and work with a trainer or doctor if needed,” says Trannah. “Recovery is really important, as well. It doesn’t help to go hard, get hurt, then be out for weeks.”



» Podcast: Why Muscle Mass is a Marker of Longevity

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