Exercise is one of the most effective ways to maintain health across the lifespan. Among the many forms of physical activity, resistance or strength training plays a particularly crucial role.
Resistance training works by asking muscles to push or pull against an external force. That resistance may come from dumbbells, barbells, weight machines, resistance bands, water, or simply the weight of the body during movements such as push-ups or squats. When muscles contract against resistance, they respond by adapting. Over time they become stronger, more resilient, and better able to produce force.
Skeletal muscle can be thought of as the body’s primary engine for movement and physical capability. When that engine becomes stronger, tasks of daily living become easier and the body functions more efficiently, from maintaining balance to regulating metabolism.
Many people still associate lifting weights with athletes or bodybuilders, but the health benefits extend far beyond appearance or physical strength.
These benefits reflect the broad role that skeletal muscle plays in human physiology. Muscle tissue influences metabolism, glucose regulation, and inflammatory signaling, which helps explain why strength training is associated with lower risks of chronic disease and mortality.
Large epidemiological studies have shown that individuals who engage in regular muscle-strengthening activities have significantly lower risks of cardiovascular disease and all-cause mortality compared with those who do not perform such exercise(1-3).
The medical potential of strength training was recognized decades ago. In the 1940s, physician Captain Thomas DeLorme used progressive weight training to rehabilitate wounded soldiers returning from World War II. His work helped establish the scientific foundation for modern strength training programs and demonstrated that muscle could be safely rebuilt through controlled resistance exercise(4).
Most public health guidelines recommend that adults perform muscle-strengthening activities at least twice per week, working all major muscle groups(2). These groups include the muscles of the legs, hips, back, chest, shoulders, arms, and core.
Although these terms sound technical, they simply describe how workouts are structured. The challenge for many people is not understanding the benefits of exercise but figuring out how to design a program that works.
To clarify these questions, researchers recently conducted one of the most comprehensive evaluations of resistance training ever assembled.
Because scientific evidence has grown dramatically since 2009, the American College of Sports Medicine (ACSM) updated its guidance using modern evidence-review methods and over 137 systematic reviews of resistance training studies. Each of these reviews already summarized dozens of individual experiments. By examining them together, researchers were able to evaluate a large body of evidence at once. This type of analysis is often called an umbrella review because it synthesizes findings from many reviews under a single framework(5).
Their goal was to determine which training variables truly influence results and which ones matter less than previously believed.
Any form of resistance training is far better than doing none.
Across studies, people who performed strength training improved in nearly every measured category compared with those who did not exercise. These improvements included greater strength, increased muscle size, improved power, better balance, faster walking speed, and stronger performance in everyday movements such as standing from a chair.
Importantly, these benefits appeared across a wide range of training styles.
Effective programs included traditional weight training, home-based exercise routines, resistance band workouts, circuit training, and bodyweight exercises such as push-ups, pull-ups, squats, lunges, and similar exercises(5).
This means progress does not require expensive equipment or complex routines. Many approaches can work.
One of the central ideas in strength training is progressive overload. This principle describes the need to gradually increase the demands placed on the muscles.
When muscles encounter a challenging stimulus, they adapt in order to handle that stress more effectively the next time. If the stimulus never changes, the body eventually adapts and progress slows.
The key is gradual progression. Small increases over time allow muscles to continue adapting without overwhelming the body.
At the same time, the research suggests that strict progression is not always necessary for beginners. Individuals who are new to strength training often experience significant improvements even when the increases in training load are modest(6).
Figure: Schematic representation of the modes of resistance training and the outcomes that are positively influenced by engaging in regular resistance training. (Adopted from Currier et. al; 2026)
One of the most practical insights from recent research is that the level of effort during a workout often matters more than the precise structure of the program.
Some people believe that every set must be performed until the muscles completely fail, but current evidence suggests that this is unnecessary and that training close to fatigue appears sufficient to stimulate muscle growth and strength improvements(7).
A useful guideline is to stop a set when you feel you could still perform two or three additional repetitions with good form. Exercise scientists refer to this as leaving 'repetitions in reserve.'
This approach provides a strong training stimulus while reducing excessive fatigue and helping maintain proper form and technique.
Training volume refers to the total amount of work performed, typically measured as the number of sets and repetitions completed.
Another thing to note is that research consistently shows that performing more than one set of an exercise leads to greater improvements than performing a single set. However, the benefits begin to taper off as volume increases(8).
For many people, two or three sets per exercise provide most of the achievable benefit. Additional sets may produce further gains, but the improvements tend to become smaller with each additional set.
Concerns about injury often discourage people, particularly older adults, from lifting weights. Yet large studies suggest these concerns are often overstated. In fact, research involving tens of thousands of participants shows that resistance training does not increase the risk of serious medical complications. Injury rates are similar to those observed during aerobic exercise such as walking or cycling(3).
Minor issues such as muscle soreness or temporary fatigue are common when starting a new exercise program, and should be expected if you are a beginner or haven't trained consistently for some time, but they usually resolve quickly and can often be managed by adjusting weight, technique, or training volume.
Despite the well-established benefits, participation in strength training remains low.
Current estimates suggest that only about 30 percent of adults perform muscle-strengthening exercise at least twice per week, while nearly 60 percent report doing none at all(2).
Among older adults, participation may fall to 10 to 15 percent. I find this statistic quite appalling and I’m certain is what contributes to many of the health issues in society.
Part of the problem is perception.
Strength training is often presented as complex, time-consuming, or accessible only in specialized gym settings. But the research tells a different story. Even relatively small amounts of resistance training can produce substantial improvements in strength, physical function, and health(6).
Resistance training is one of the most effective and underused strategies for protecting long-term health.
By strengthening muscles, it supports mobility, metabolic health, balance, and independence throughout aging. The evidence also suggests that people do not need perfect programs or elaborate routines to benefit.
Consistency and effort matter far more than optimization.
A wide range of training approaches can improve strength and physical function, provided the muscles are challenged regularly.
The most important step is simply to begin and be consistent. When muscles are used and challenged, the body adapts. Over time those adaptations accumulate, supporting strength, health, and resilience throughout life.
While most people get fixated on the physical benefits of exercise, there are many more important benefits to your brain too.
You can learn how hard workouts rewire your brain your brain's access to pain relief and stress control here.
References:
