Scientists find the strength training “sweet spot” for a longer life

While strength training has historically been associated with building muscle and improving appearance, a recent study reveals its potential to significantly contribute to longer life expectancy, even with minimal time investment. Researchers analyzed data from three extensive US studies, encompassing nearly 150,000 nurses and health professionals observed for up to three decades.

Participants recorded their weekly strength training and aerobic exercise, and approximately 36,000 eventually passed away, allowing for an examination of how muscle-strengthening activity correlated with early mortality risk. The findings highlighted an optimal range of strength training: around 90 to 120 minutes weekly – roughly an hour and a half to two hours – associated with a 13% reduced risk of death from any cause compared to non-participants.

This beneficial effect was particularly pronounced for two leading causes of death: a 19% lower risk of cardiovascular-related deaths, including heart disease and stroke, and a 27% reduction in neurological conditions, primarily dementia. However, exceeding two hours weekly did not further diminish the risk. Interestingly, combining strength training with regular aerobic exercise, such as walking, jogging, cycling, or swimming, yielded the most pronounced benefits, with about a 45% lower risk of death.

Even the recommended amount of moderate aerobic activity (around 150 minutes a week) was linked to a 26% to 43% lower mortality risk. The study suggested that muscle, particularly skeletal muscle developed through resistance training, plays a pivotal role. Muscles act as a highly metabolically active tissue, primarily responsible for absorbing glucose from the bloodstream during and after meals.

Insulin, released after eating, facilitates this process, leading to either energy utilization or glycogen storage rather than fat accumulation. Thus, maintaining robust muscle mass can bolster blood sugar control, safeguarding against type 2 diabetes, a major contributor to heart disease and early mortality. Additionally, muscle contractions release myokines, hormone-like signaling molecules that modulate inflammation and influence organ function across the body.

Regular resistance training can also positively impact heart health by lowering blood pressure and maintaining arterial flexibility, thereby protecting against cardiovascular disease. Stronger muscles can mitigate falls and fractures, enhance independence in later life, and reduce frailty, all of which are crucial for longevity.

While the study was observational and couldn't definitively establish causation, it did adjust for various confounding factors such as diet, smoking habits, and aerobic activity. Grip strength, an indicator of overall muscular fitness, has been shown to predict early mortality risk more accurately than blood pressure alone. Moreover, the link between strength training and brain health is emerging, with resistance training potentially influencing neuroprotective factors such as improved blood sugar regulation and vascular health.

However, the study's limitations include the self-reported nature of strength training duration and intensity, as well as the absence of objective measures for workout intensity. Nonetheless, the results suggest that incorporating two short strength training sessions weekly, complemented by daily aerobic exercise, can substantially improve overall health and longevity, making it an attainable goal for most individuals.