One of the most impactful things you can do for yourself this year is to focus on your muscle power. In today's email, I'll explain why.
 

Muscle power—your ability to generate force quickly—is one of the strongest predictors of longevity, even more so than being lean. This is sometimes referred to as the 'fat but powerful' paradox.
 

In a recent study, older adults with normal and high levels of relative muscle power had better 9-year survival than older adults with low muscle power.
 

Muscle power was even protective against death in older adults with high levels of body fatness measured using BMI and waist circumference.
 

Being fat and powerful reduced mortality just as much as being lean and powerful—by 43–45%. 
 

Being lean and weak, however, provided no survival advantage compared to being fat and weak.
 

Interestingly, when body fatness was measured using body fat percentage or the fat index (body fat % normalized to height), the protective effect of muscle power was mitigated—only lean and powerful participants experienced a mortality benefit.
 

This highlights the continued importance of minimizing excess adiposity for long-term health, even when physical fitness is optimized.

https://bjsm.bmj.com/content/55/21/1204

The takeaway here isn’t to downplay the risks of obesity for longevity—maintaining a healthy weight is still critical. But fitness, particularly muscle power, deserves more attention as a key lever we can pull to improve both lifespan and healthspan. It’s one of the most actionable metrics to track and improve. 

Muscle power is crucial because not only does it help us perform better when playing sports or exercising in the gym, but it also determines how well we do activities of daily living like climbing stairs, getting up out of a chair, and protecting ourselves against falls.
 

It's so important that researchers have proposed a new term for the age-related loss of muscle power: powerpenia (a friendly nod to the more well-known term sarcopenia, which refers to the age-related loss of muscle mass).

How aging impacts muscle 

In previous episodes of the FoundMyFitness podcast, I've shared expert evidence on how our bodies decline with age and inactivity.
 

Around age 50, muscle strength—the ability to exert force or lift heavy resistance—declines by about 3% per year, while muscle mass decreases by about 1% per year. 

The solution is simple: Resistance training and sufficient protein intake. Engaging in strength training 2–3 times per week and consuming 1.2–1.6 grams of protein per kilogram of body weight per day can help maintain—and even build—muscle mass and strength as we age.
 

It's not inevitable that we lose muscle as we get older. But it takes effort. 
 

These declines in muscle strength and mass might seem significant, but muscle power might experience even more drastic changes.

Muscle power is an underappreciated aging biomarker

Why are researchers suggesting that we discriminate the loss of muscle strength and mass (sarcopenia) from muscle power (powerpenia)?
 

There are several reasons:

First is the greater decline with age. Muscle power declines more rapidly than muscle mass or strength during aging. This accelerated loss makes power a more sensitive marker of aging and functional decline.

Second is its functional relevance. Muscle power is more strongly associated with critical functional outcomes, such as mobility, fall prevention, and physical independence in older adults, compared to muscle strength or muscle mass.

Third is related to the physiological mechanisms that govern power compared to mass or strength. Muscle power involves the product of force and velocity, requiring both neuromuscular coordination and muscle contractility. This differentiates it from strength, which only measures maximal force, and mass, which focuses solely on size.

Fourth is its independent predictive value. Loss of muscle power (termed “powerpenia”) is a better predictor of adverse health outcomes, such as falls and mortality, compared to strength or mass, particularly in clinical and aging populations.

https://sportsmedicine-open.springeropen.com/articles/10.1186/s40798-024-00689-6

Training for power

If muscle power is so important—and the loss of it so detrimental to health and physical function—the question then becomes: How do we improve it?

The answer: High-velocity resistance training—what we'll refer to as power training.

Power training, which emphasizes speed and velocity of muscle contractions, provides unique benefits for improving functional outcomes that traditional strength training does not. This type of training typically produces 10–97% greater improvements in muscle power when compared to traditional strength training.

In power training, one emphasizes the concentric phase of the exercise (think the lifting phase of a bicep curl or the pushing phase of a bench press), performing it as fast as possible while maintaining proper form. The focus is on fast, powerful movements! Here are some examples of power training exercises:

• Climbing a set of stairs as quickly as possible - you can modify this by wearing a weighted vest or carrying dumbbells.
• Standing up from a chair as many times as possible within 30 to 60 seconds - you can take a rest break and repeat this as many times as possible as a form of interval training.
• Fast step-ups using your own body weight or while holding dumbbells or wearing a weighted vest.
• Performing push-ups or pull-ups as quickly as possible with a weighted vest or using your own body weight.

You can also turn traditional exercises like squats, deadlifts, bench presses, and clean and jerks into power training by performing the concentric phase as quickly as possible. As long as you can maintain proper and safe lifting form!

Final thoughts

If there's anything that I've learned from numerous interviews with world-leading experts in the science of exercise, it's that muscle is our most important organ. It influences our metabolic health, our brain health, and most importantly, our ability to live a healthy and frailty-free life.
 

It's time that we retire the myth that strength training is just for athletes and body builders—there is not a single person on earth who won't benefit from a structured resistance training program. Whether you want to get stronger, build more muscle, or become more powerful isn't important. What's important is to just get training! The sooner you start the better.

If you're interested in learning more about my current resistance training framework and nutritional strategies for building muscle, check out these member Q&A episodes that we've hand picked just for you.

With appreciation,

Rhonda and the FMF Team