A new study suggests that spending just 90 to 120 minutes a week on strength training may do more than build muscle—it could help people live longer and reduce their risk of serious diseases.
Researchers from the Harvard T.H. Chan School of Public Health found that adults who regularly engaged in resistance training experienced lower rates of death from cardiovascular and neurological diseases compared to those who did not. The findings add to a growing body of evidence showing that exercise isn’t just about fitness goals; it may be one of the most effective tools for healthy aging.
The study was published in the British Journal of Sports Medicine.
TL;DR
- A Harvard-led study tracked more than 147,000 adults over several years.
- People who performed 90 to 120 minutes of strength training per week had the greatest health benefits.
- Participants in that range saw:
- 13% lower risk of death from any cause.
- 19% lower risk of cardiovascular-related death.
- 27% lower risk of death from neurological diseases, including dementia.
- The strongest results came from combining strength training with aerobic exercise.
- Researchers found a correlation, not proof of causation.
What Did the Study Find About Strength Training and Longevity?
The research analyzed data from 147,374 adults who participated in three long-running U.S. health studies. Participants were aged 54 and older and reported their exercise habits every two years, including both aerobic activities and strength-training routines.
Researchers defined strength training broadly, including:
- Pushups
- Squats
- Lunges
- Traditional weightlifting
- Other resistance-based exercises
During the study period, approximately 36,000 participants died, allowing researchers to examine how different exercise patterns affected long-term health outcomes.
The most notable finding was the existence of a potential “sweet spot” for resistance training.
Adults who averaged between 90 and 119 minutes of strength training each week experienced:
- A 13% lower risk of death from any cause.
- A 19% lower risk of death from cardiovascular disease.
- A 27% lower risk of death from neurological diseases, primarily dementia.
The findings suggest that relatively modest amounts of resistance training may provide significant health benefits.
Why Does Strength Training Matter for Healthy Aging?
For decades, aerobic exercise such as running, cycling, and brisk walking has dominated conversations about longevity. Strength training, meanwhile, has often been associated primarily with athletic performance or muscle building.
That perception is changing.
Scientists increasingly view muscle mass as an important marker of overall health, particularly as people age. Maintaining strength can help preserve mobility, reduce the risk of falls, improve metabolic health, and support independence later in life.
Muscle Is More Than a Fitness Metric
Muscle tissue plays a role in regulating blood sugar, supporting joint stability, and reducing inflammation. As people age, they naturally lose muscle mass—a process known as sarcopenia.
Resistance training helps slow or even reverse some of that decline.
This may explain why participants who regularly engaged in strength training appeared to have better long-term health outcomes than those who remained inactive.
How Could Strength Training Protect the Brain?
One of the study’s most intriguing findings involved neurological health.
Researchers observed a 27% lower risk of death from neurological diseases among participants who performed strength training within the identified sweet spot.
The Role of IGF-1
Resistance training stimulates the release of Insulin-Like Growth Factor 1 (IGF-1), a hormone linked to brain health.
Scientists believe IGF-1 may help:
- Support the integrity of white matter in the brain.
- Improve communication between brain regions.
- Maintain cognitive processing speed.
- Slow age-related cognitive decline.
White matter acts as the brain’s communication network, helping signals travel efficiently between different regions. Preserving its structure may be important for memory, learning, and overall cognitive function.
While researchers continue to investigate the exact mechanisms involved, the findings provide another reason why strength training may benefit more than muscles alone.
Is More Strength Training Always Better?
Not necessarily.
One of the study’s more surprising conclusions was that benefits appeared strongest within a specific range rather than increasing indefinitely.
Researchers identified approximately 90 to 120 minutes per week as the optimal amount associated with lower mortality risk.
This doesn’t mean exercising beyond that threshold is harmful. Rather, the study suggests that the greatest measurable benefits occurred within that window.
For many adults, that translates to:
- Three 30-minute strength-training sessions per week.
- Two 45-minute sessions per week.
- Four shorter workouts spread throughout the week.
The findings may be especially encouraging for people who feel intimidated by lengthy workout routines.
As the study authors noted, small amounts of activity can still make a meaningful difference.
Why Combining Strength Training and Cardio Produces the Biggest Benefits
Perhaps the most important takeaway from the research is that resistance training works best when paired with aerobic exercise.
Adults who participated in both forms of exercise experienced a 45% lower risk of death compared with those who engaged in neither activity.
This combination likely delivers complementary benefits.
What Strength Training Provides
- Muscle preservation
- Bone density support
- Improved metabolic health
- Better balance and mobility
What Aerobic Exercise Provides
- Cardiovascular conditioning
- Improved lung function
- Better blood circulation
- Enhanced endurance
Together, they create a more comprehensive approach to long-term health.
For older adults in particular, combining resistance and aerobic training may help maintain both physical function and disease resistance.
What Are the Study’s Limitations?
While the findings are compelling, researchers caution against drawing overly broad conclusions.
The study identifies an association between strength training and reduced mortality risk. It does not prove that resistance training directly caused participants to live longer.
Several limitations should be considered:
- Participants self-reported their exercise habits.
- Most participants were white.
- The cohort primarily consisted of middle-aged and older healthcare professionals.
- Results may not fully apply to younger populations or more diverse groups.
Researchers also cannot rule out the possibility that people who strength train regularly engage in other healthy behaviours that contribute to longer life expectancy.
In other words, strength training appears strongly linked to better outcomes, but it may be only one piece of a larger picture of a healthy lifestyle.
What Does This Mean for Everyday Adults?
The study delivers a practical message: you don’t need to spend hours in the gym to see meaningful health benefits.
For many adults, the goal could be as simple as building a sustainable weekly routine that includes:
- Two to four strength-training sessions.
- Regular walking, cycling, swimming, or other aerobic activity.
- Progressive increases in activity over time.
The findings also challenge the misconception that strength training is only for athletes or bodybuilders.
Whether through bodyweight exercises, resistance bands, free weights, or gym machines, resistance training appears to be an important component of healthy aging.
The Bottom Line
The latest Harvard-led research suggests that around 90 to 120 minutes of strength training per week may offer significant benefits for longevity, cardiovascular health, and brain health.
More importantly, the greatest gains were observed among people who paired resistance training with regular aerobic exercise.
While the study does not prove cause and effect, it adds to growing evidence that maintaining muscle strength is about far more than appearance. It may be one of the most effective investments people can make in their long-term health.
For those who have been putting off strength training, the research offers an encouraging message: a few workouts each week may go a long way.