While modern technology has led many individuals to meticulously track various health metrics like cardiovascular fitness, blood pressure, and sleep data through devices such as Apple Watches and Oura Rings, experts suggest a crucial element for longevity is often overlooked: muscle health. The concept of 'longevity' has gained significant traction, yet the focus has predominantly remained on traditional indicators, neglecting the profound impact of muscle strength and mass on extending a healthy lifespan. Dr. Gabrielle Lyon, a leading expert in the field, introduces the term 'musclespan' to describe the sustained support of strength and healthy aging. She defines it as the duration one can live with robust skeletal muscle, emphasizing that the strength and mass of these muscles are powerful indicators of overall longevity.

Muscle's importance extends far beyond mere movement; Dr. Lyon highlights its role as a vital metabolic and endocrine organ. This means muscle tissue influences critical bodily functions such as insulin sensitivity, metabolic health, and even the immune system. She asserts that a strong muscular foundation provides essential resilience against illness, stating, "It's not if, but when, illness strikes because it happens to all of us. If you are prepared with both strength and mass then you are much more likely to be able to overcome life's challenges." This protective capability is attributed to myokines, hormones produced by muscles, which significantly reduce inflammation, protect against various diseases, and promote longevity. A study published in Endocrine Reviews further underscored this, suggesting myokines might explain why regular exercise lowers the risk of certain cancers, heart disease, and dementia. Dr. Khemani, a clinical professor at Stanford University, elaborates that these "powerful messengers allow muscle to 'talk' to other organs, including the brain tissue, liver and immune system, helping regulate vital processes like blood sugar control, metabolism, mood and brain health." Consequently, muscle health is intricately linked to metabolic health, cognitive function, longevity, and disease resilience, making it a primary predictor of one's lifespan and quality of life.

Assessing and improving your musclespan can begin at home. Beyond essential workouts like interval training, a healthy diet, and restorative sleep, tracking your baseline muscle strength through functional movements offers valuable insights. Dr. Lyon advocates that everyone should be capable of performing squats, push-ups, and pull-ups. Research has specifically identified push-ups as an excellent measure of musclespan over time; a study notably found that men able to perform 40 push-ups had a lower mortality risk than those who could only manage 10. While the exact number of repetitions may differ for women, similar benefits are expected with fewer reps. Dr. Lyon suggests aiming for benchmarks of 10 push-ups, 1 unassisted pull-up, and at least 25 squats.

Another simple yet effective test is the one-minute grip test, which assesses the force exerted when squeezing an object. Long recognized as an accessible measure of physical health, strong grip strength correlates with a reduced risk of dying from various age-related conditions, including heart disease, type 2 diabetes, arthritis, and certain cancers. Conversely, weak grip strength can signal sarcopenia, a detrimental level of muscle loss characterized by declining muscle mass and function. Experts now view grip strength as a strong indicator of how other bodily functions may weaken over time.

To enhance musclespan, Heather Milton, an exercise physiologist at New York University, recommends incorporating strength training that targets all major muscle groups twice weekly. Dr. Lyon advises against extended periods of sedentary behavior, stressing that "the more active you are, the more you prime your body for muscle." When performing strength exercises, she suggests selecting a weight that allows you to complete one or two more repetitions before reaching failure or compromising form. This intensity ensures sufficient stress on muscles, promoting adaptation, growth, and repair. However, she cautions against daily high-intensity exercise targeting the same muscle groups without adequate rest, as this can be detrimental. "That's why sleep is imperative: when we sleep, the hormones that create those adaptations are at their peak." Beyond strength training, monitoring VO2 max—the maximum oxygen utilization during exercise—can offer further insights into muscle health and longevity. Dr. Lyon also recommends regular blood tests (every three to four months) to track metabolic markers such as blood sugar, cholesterol, and triglycerides, which are indicators of metabolic syndrome—a condition closely linked to unhealthy skeletal muscle. Ultimately, while musclespan isn't developed overnight, robust data confirms that it's never too late, nor too early, to prioritize and improve muscle health. Muscle health, strength, and mass have emerged as some of the most reliable predictors of healthy aging.