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New research debunks longheld myth that keeps millions of older adults from hitting the gym
In a nutshell
Age is not a barrier to recovery: Older adults don’t experience greater muscle damage after exercise compared to younger adults, contrary to popular belief.
Less soreness reported: Older adults consistently report less muscle soreness than younger people after intense exercise.
Physical changes may be protective: Age-related changes in muscle and connective tissue may actually help protect against exercise-induced damage.
LANCASTER, England — Conventional wisdom has long suggested that as we age, our bodies become more fragile and take longer to bounce back from physical stress. But what if that’s not entirely true? Research challenges this notion with surprising evidence that older adults may not experience worse exercise-induced muscle damage than their younger counterparts.
The new findings could change how older adults approach physical activity by removing a significant psychological barrier that has kept many from engaging in beneficial exercise regimens. In other words, perhaps all along millions of people have held back from working out as they age due to fear stemming from unsubstantiated beliefs.
Challenging Beliefs About Muscle Aging and Recovery
For years, the scientific community theorized that aging bodies would struggle more with exercise recovery. The reasoning seemed sound: older adults typically show decreased muscle protein synthesis (the body’s ability to build new muscle), fewer satellite cells (essential for muscle repair), and reduced ability for those cells to multiply. These factors should logically result in greater muscle damage and slower recovery times.
However, the data from 36 studies tells a markedly different story. The international research team, spearheaded by scientists from Cardiff Metropolitan University, conducted a thorough review comparing exercise recovery between different adult age groups.
Many older adults avoid weightlifting because they fear they’ve reached an age where it could cause more harm than good. New research debunks this myth. (Photo by Unsplash+ in collaboration with Getty Images)
When researchers measured muscle function changes after exercise – a key indicator of how well muscles perform after being stressed – they found no meaningful differences between younger and older participants. This crucial performance metric remained similar between age groups at 24, 48, and 72 hours post-exercise, as well as in measurements of peak changes.
More surprisingly, older adults consistently reported less muscle soreness than younger participants at all measured time points. This pattern held steady across multiple studies and contradicts what most exercise physiologists would have predicted.
Similarly, creatine kinase levels – an enzyme that appears in the bloodstream when muscle membranes are damaged – were lower in older adults compared to younger adults at 24 hours post-exercise and at peak measurements.
Why Older Muscles Might Be More Resilient
The researchers proposed several explanations for these unexpected findings.
One theory involves the physical changes that happen in muscle and connective tissue with age. As we get older, our skeletal muscles contain more collagen, which can stiffen both muscle and connective tissue. Similar to how muscles adapt to repeated exercise, aging might cause mechanical changes that improve muscle stiffness, offering protection against structural damage by better distributing physical stress during workouts.
Fatigue responses may also play a role. Research has shown that older adults typically experience greater muscular fatigue during dynamic movements. Since all studies in this analysis used dynamic contractions to cause muscle damage, older adults may have experienced a reduced absolute workload compared to younger participants, despite working at the same relative intensity. This lower absolute load might result in less tissue damage.
The research team also examined whether factors like sex, body part exercised, or exercise type influenced the results. Sex did appear to play a role in muscle function responses, with similar numerical differences between age groups for both males and females, but only the male comparison reached statistical significance. This hints that age may affect male muscle responses differently than female responses, though the researchers note fewer studies focused on women, which may have affected this finding.
There are many studies that show the incredible benefits of keeping your muscles strong and active in old age. (© Krakenimages.com – stock.adobe.com)
The Struggle Isn’t Real
Exercise-induced muscle damage can discourage people from sticking with physical activity programs, particularly older adults who might view the discomfort as harmful rather than as part of the adaptation process. Now, knowing that aging doesn’t necessarily increase vulnerability to muscle damage could help overcome this mental barrier.
Perhaps most important, the research offers encouragement for aging individuals to stay active. With global population trends pointing toward an increasingly older demographic – people over 60 expected to double by 2050 and triple by 2100 – understanding how aging affects exercise responses becomes increasingly vital to public health.
Physical activity remains fundamental to “successful aging,” which includes physical, psychological, social, and cognitive aspects. Regular exercise can offset age-related declines in muscle strength and power, aerobic fitness, and body composition. This new understanding that older adults may not face excessive muscle damage removes a significant obstacle to activity.
For the average older adult considering starting or continuing an exercise program, this research delivers a clear message: your age should not hold you back. Your muscles may actually handle exercise stress better than previously thought, and the benefits of regular physical activity far outweigh the temporary discomfort of muscle damage. Be sure to speak with your doctor first before taking on any new physical challenges.
Paper Summary
Methodology Explained
This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, the gold standard for this type of research. The team searched three major databases (Google Scholar, PubMed, and SPORTDiscus) in June 2023, seeking studies that compared exercise-induced muscle damage between younger and older adults. From an initial pool of 1,092 potentially relevant articles, they narrowed the selection to 36 studies meeting specific criteria. To be included, studies needed to compare younger and older adult groups performing an exercise bout without recovery aids, and measure at least one marker of muscle damage at least 24 hours afterward. The analysis included data from 389 younger and 390 older adults. The researchers used standardized mean difference calculations with 95% confidence intervals to analyze age group differences, allowing comparison across studies using different measurement methods. They also conducted additional analyses to examine whether factors like sex, exercise type, or body part exercised affected the results.
Results Breakdown
The analysis revealed several key findings about exercise-induced muscle damage across age groups. For muscle function measures like strength and power, there were no significant differences between younger and older adults at any measured time point or in peak changes. The standardized mean difference values ranged from -0.16 to -0.35, showing small and non-significant differences. For muscle soreness, older adults consistently reported less pain than younger adults at all time points, with effect sizes ranging from small to moderate (SMD -0.34 to -0.62), all reaching statistical significance. Similarly, creatine kinase levels were lower in older adults at 24 hours post-exercise (SMD = -0.32) and in peak measurements (SMD = -0.32), both statistically significant. When examining additional factors, the researchers found a relationship between sex and peak muscle function changes in males (SMD = -0.45, p = 0.024) but not females (SMD = -0.44, p = 0.663), suggesting potential sex differences in age-related responses to exercise. Other analyses examining exercise type and body part exercised did not reveal significant relationships.
Study Limitations
The authors acknowledge several constraints to their meta-analysis. A significant limitation is the cross-sectional design of the included studies, which compared different age groups rather than tracking changes in the same individuals over time. This approach identifies differences between age groups but cannot directly measure aging effects. The studies also varied in how they defined “young” and “old” adults, with no standard age thresholds across the literature. Another limitation involves potential differences in absolute workload during exercise protocols. Since older adults typically have less muscle mass and strength, they may have performed less absolute work despite working at the same relative intensity as younger participants, potentially resulting in less muscle damage. The analysis also included relatively few studies with female participants, limiting the power of sex-based comparisons. Finally, the researchers note considerable variability in some analyses, indicating differences in study results that could be influenced by factors not fully captured in their additional analyses.
Funding and Disclosures
The paper does not specifically mention any funding sources or conflicts of interest. The research was conducted by an international team of scientists from various institutions including Cardiff Metropolitan University, Middlesex University, Brunel University, Hartpury University, Liverpool John Moores University, Northumbria University, Washington Spirit, and Lancaster University. The authors’ institutional affiliations are clearly stated, providing transparency about the collaborative nature of this research project.
Publication Information
This meta-analysis, titled “Advancing Age Is Not Associated With Greater Exercise-Induced Muscle Damage: A Systematic Review, Meta-Analysis, and Meta-Regression,” was published in the Journal of Aging and Physical Activity in 2025. The paper was authored by John F.T. Fernandes, Laura J. Wilson, Amelia F. Dingley, Andrew N. Hearn, Kelsie O. Johnson, Kirsty M. Hicks, Craig Twist, and Lawrence D. Hayes. The publication is available online at https://doi.org/10.1123/japa.2024-0165.