Preserving Muscle With Age: What Diet and Exercise Can Do

Aging alters how muscles react to food and physical activity, prompting questions about protein needs, meal timing, and which supplements may genuinely help support muscle health.

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Introduction

Skeletal muscle does more than power movement. It also helps regulate blood glucose, responds to exercise, and releases substances that communicate with other tissues, which is why diet and physical activity remain important throughout adult life.

Protein is central to that discussion, but the evidence behind supplements and other nutrition strategies is uneven. This article looks at protein intake, nutrients under study, the gut-muscle connection, and resistance exercise, while separating established findings from proposed mechanisms.

Why muscle is more than movement

Skeletal muscle makes up a large share of body mass and is a major site for glucose uptake. Along with structural and mechanical support, it also releases signaling molecules known as myokines.²

When muscles contract, muscle-derived molecules such as interleukin-6 (IL-6) can send signals to the liver, fat tissue, and other organs.² IL-6 that rises briefly during exercise behaves differently from the chronically elevated inflammatory signaling linked with excess visceral fat. Its effects depend on where it comes from and the biological setting.

These metabolic and signaling roles help explain why preserving muscle becomes especially important with aging, illness, and inactivity.^1,2

Muscle across the lifespan

Muscle mass usually peaks in early adulthood and then declines gradually from mid-adulthood onward, with losses often speeding up later in life.³ Age-related muscle loss involves several connected processes, including changes in protein turnover, the balance between muscle protein synthesis and breakdown, mitochondrial function, muscle repair, and inflammation.^3,4 The ubiquitin-proteasome system and autophagy help clear damaged cellular material.⁴

Keeping muscle strength and function matters more with age because sarcopenia is linked with falls, disability, and other negative outcomes. Healthier diets earlier in adulthood are more consistently associated with better physical performance later in life than with a lower rate of diagnosed sarcopenia.⁶

How to Save Your Muscles From Aging

Protein: necessary, but not the whole story

Dietary protein supplies the amino acids needed for muscle protein synthesis, the process that builds new muscle proteins. Leucine, an amino acid found in protein-rich foods, helps activate a signaling pathway involved in that process.¹

A meta-analysis of 17 randomized trials in older adults found that isolated leucine supplementation did not significantly improve total lean mass or the strength outcomes examined. Some nutrient combinations, including leucine and vitamin D, were linked with better handgrip strength and gait speed, but those findings do not show which ingredient caused the benefit.⁵

The U.S. recommended dietary allowance for protein in adults is 0.8 grams per kilogram of body weight per day. The protein review suggests that older adults may benefit from higher intakes, often around 1.0 to 1.2 grams per kilogram per day, especially if they are physically active and respond less strongly to protein intake.¹

The ideal target for any one person is still uncertain and may depend on health status and activity level.^1,6 Importantly, higher targets should not be applied automatically to people with existing kidney damage.¹

Animal proteins often contain higher proportions of certain amino acids than individual plant proteins. A varied plant-based diet can still provide enough protein, but the evidence cited here does not show that all plant and animal sources lead to identical muscle outcomes.^1,6 Comparisons also depend on digestibility, the amount eaten, and the amino acid profile of the meal.¹

Exercise and nutrition: a partnership

Resistance exercise places demands on muscle that trigger adaptation, while food provides the energy and amino acids needed for recovery.^1,7 Older muscle often shows a weaker protein-building response to a protein meal, known as anabolic resistance. Exercise can improve that response, which is why protein intake and muscle activity should be viewed together.^1,3

Resistance training has especially strong support as a strategy for managing sarcopenia.^6,7 Adding protein supplements does not consistently improve every muscle outcome, so getting enough protein should not be confused with a universal need for supplementation.⁶

Researchers have also examined whether distributing protein more evenly across meals improves muscle protein synthesis.¹ Results in older adults are mixed for both protein synthesis and lean mass. In addition, short-term responses do not prove that an even distribution prevents long-term losses in strength or physical function.¹

Beyond protein: nutrients that support muscle function

Getting enough food overall helps meet the energy demands of daily life and exercise. Carbohydrates can aid recovery after activity, though their importance depends on the amount and type of exercise performed.⁷

Creatine supplementation may increase lean tissue mass and strength in older adults, especially when paired with resistance training.⁸ Creatine helps regenerate adenosine triphosphate (ATP), the energy source for brief, intense muscle contractions.⁸

Omega-3 fatty acids have also been studied for possible effects on inflammation and muscle metabolism. Even so, findings differ across outcomes, and the evidence does not show consistent benefits for muscle mass, strength, or physical performance.^6,7

Low vitamin D has been associated with poorer physical function. Still, a meta-analysis of 10 randomized trials found that vitamin D supplementation alone did not improve muscle mass, strength, or overall physical performance in community-dwelling older adults.⁹

The review did find a small reduction in Short Physical Performance Battery scores, which assess balance, walking speed, and chair-rise performance. However, that average change does not prove clinically meaningful harm for every participant, and the findings should not be extended to every use of vitamin D.⁹

Another active area of research is the gut-muscle axis. Laboratory and animal studies suggest that short-chain fatty acids made by intestinal microorganisms may influence muscle metabolism and inflammation. Small human intervention studies have reported encouraging results, but the evidence is still too limited to show that microbiome changes reliably prevent age-related muscle loss.¹⁰

Muscle, metabolism, and chronic disease

Skeletal muscle is a major consumer of glucose, so changes in its size and function can affect metabolic health. Sarcopenia can also occur alongside excess body fat, a combination often referred to as sarcopenic obesity.⁶

Low muscle mass and poor muscle function can coexist with obesity and metabolic disease. Insulin resistance and chronic inflammation may contribute to both metabolic dysfunction and muscle decline, but these associations do not prove a single direction of causation. Fat can also build up inside muscle, where it has been linked with poorer muscle quality and insulin resistance. Inflammation and altered muscle signaling may help explain these relationships.^3,7,10

Future directions in muscle nutrition

Researchers are studying metabolic markers linked with sarcopenia.¹⁰ Approaches that combine dietary, activity, and microbiome data may eventually help tailor interventions, but they are not yet established tools for diagnosing sarcopenia or prescribing individualized diets.¹⁰ Larger and longer human trials are needed to determine whether these strategies produce lasting gains in strength and physical function.¹⁰

Conclusion: maintaining muscle throughout adulthood

Skeletal muscle supports mobility and metabolic health throughout life. Adequate food and protein intake, high-quality diet patterns, and regular resistance exercise provide a solid foundation for maintaining muscle health.^6,7

Supplement effects differ by formulation and outcome. Creatine has evidence for improving lean tissue mass and strength when combined with resistance training, while isolated leucine, vitamin D alone, and microbiome-based strategies have less consistent or insufficient evidence for preventing muscle loss.^5,8,9,10

References

1. Morgan, P. T., Witard, O. C., Højfeldt, G., et al. (2025; first published online 2023). Dietary protein recommendations to support healthy muscle aging in the 21st century and beyond: considerations and future directions. Proceedings of the Nutrition Society 84; 245-258. DOI: 10.1017/S0029665123003750. https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/dietary-protein-recommendations-to-support-healthy-muscle-ageing-in-the-21st-century-and-beyond-considerations-and-future-directions/A60A684B6FA52A6C5BFC315A98BF8146.
2. Nishii, K., Aizu, N., & Yamada, K. (2023; first published online 2022). Review of the health-promoting effects of exercise and the involvement of myokines. Fujita Medical Journal 9(3); 171-178. DOI: 10.20407/fmj.2022-020. https://www.jstage.jst.go.jp/article/fmj/9/3/9_2022-020/_article
3. McCormick, R., & Vasilaki, A. (2018). Age-related changes in skeletal muscle: changes to lifestyle as a therapy. Biogerontology 19(5), 519-536. DOI: 10.1007/s10522-018-9775-3. https://link.springer.com/article/10.1007/s10522-018-9775-3
4. Hughes, D. C., Baehr, L. M., Waddell, D. S., et al. (2022). Ubiquitin ligases in longevity and aging skeletal muscle. International Journal of Molecular Sciences 23(14); 7602. DOI: 10.3390/ijms23147602. https://www.mdpi.com/1422-0067/23/14/7602.
5. Guo, Y., Fu, X., Hu, Q., et al. (2022). The effect of leucine supplementation on sarcopenia-related measures in older adults: a systematic review and meta-analysis of 17 randomized controlled trials. Frontiers in Nutrition 9; 929891. DOI: 10.3389/fnut.2022.929891. https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.929891/full.
6. Robinson, S., Granic, A., Cruz-Jentoft, A. J., & Sayer, A. A. (2023). The role of nutrition in the prevention of sarcopenia. The American Journal of Clinical Nutrition 118(5); 852–864. DOI: 10.1016/j.ajcnut.2023.08.015. https://www.sciencedirect.com/science/article/pii/S0002916523661131?via%3Dihub.
7. Feng, L., Li, B., Yong, S. S., et al. (2024). Exercise and nutrition benefit skeletal muscle: from influence factor and intervention strategy to molecular mechanism. Sports Medicine and Health Science 6, 302–314. DOI: 10.1016/j.smhs.2024.02.004. https://www.sciencedirect.com/science/article/pii/S2666337624000258?via%3Dihub
8. Candow, D. G., Forbes, S. C., Chilibeck, P. D., et al. (2019). Effectiveness of creatine supplementation on aging muscle and bone: focus on falls prevention and inflammation. Journal of Clinical Medicine 8(4); 488. DOI: 10.3390/jcm8040488. https://www.mdpi.com/2077-0383/8/4/488
9. Prokopidis, K., Giannos, P., Katsikas Triantafyllidis, K., et al. (2022). Effect of vitamin D monotherapy on indices of sarcopenia in community-dwelling older adults: a systematic review and meta-analysis. Journal of Cachexia, Sarcopenia and Muscle 13(3); 1642-1652. DOI: 10.1002/jcsm.12976. https://onlinelibrary.wiley.com/doi/10.1002/jcsm.12976.
10. Xu, Y., & He, B. (2025). The gut-muscle axis: a comprehensive review of the interplay between physical activity and gut microbiota in the prevention and treatment of muscle wasting disorders. Frontiers in Microbiology 16; 1695448. DOI: 10.3389/fmicb.2025.1695448. https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2025.1695448/full.