Nutrition for Masters Runners Over 40: Fuel, Recovery, and Muscle Protection

What actually changes physiologically after 40

Running performance changes with age, but the mechanisms are more nuanced than "you just slow down." The physiologically relevant changes for masters runners — those over 40 — include a gradual decline in anabolic hormone production (testosterone and growth hormone), reduced muscle protein synthesis rates in response to the same stimulus, slower recovery from hard efforts, reduced bone density in some individuals, and increased injury risk from connective tissue changes.

None of these changes are inevitable or unmanageable, but they do require nutrition adjustments compared to what worked at 25 or 30. The runners who continue performing well into their 40s and 50s are typically those who have adapted their training and nutrition to their current physiology rather than trying to replicate the approaches of their younger years.

Protein: the most critical nutrition adjustment after 40

Muscle protein synthesis — the rate at which the body builds and repairs muscle in response to training — declines with age. This phenomenon is called anabolic resistance: older muscle requires more protein to produce the same synthetic response as younger muscle. The practical consequence is that protein requirements for masters athletes are meaningfully higher than for younger athletes doing the same training.

The current evidence suggests masters runners target 1.8–2.4g of protein per kilogram of body weight per day — at the upper end of general athletic recommendations. For a 65kg masters runner, this means 117–156g of protein daily. For most, this requires deliberate planning rather than incidental adequacy.

Per-meal protein distribution is particularly important for older athletes. Research shows that 40g of high-quality protein per meal produces a stronger synthetic response than 20g in masters athletes — while younger athletes may respond similarly to both amounts. Larger protein portions at each meal, spread across 3–4 eating occasions, is the most evidence-based approach for muscle maintenance with age.

Carbohydrates: still essential, periodized to training load

Some masters runners fall into the trap of drastically reducing carbohydrates as they age — influenced by weight management concerns or general low-carb dietary trends. For runners who are still training meaningfully (3+ sessions per week), this approach consistently backfires: it reduces training quality, slows recovery, and increases fatigue without the intended body composition benefits.

Carbohydrate needs scale with training load, not age. A masters runner training 6 hours per week needs carbohydrates to support that training volume — the fuel requirement doesn't go away because of a birthday. What changes is the recommendation to periodize carbohydrates more deliberately: higher intake around hard sessions and long runs, lower intake on rest and easy days, with total weekly intake reflecting actual training demand rather than arbitrary restriction.

Recovery nutrition: why it matters more with age

Recovery from hard training sessions takes longer in masters athletes than in younger runners — this is one of the most consistently reported experiences in age-group athletics. The physiological basis is real: the inflammatory response to training is larger, anabolic signaling is blunted, and tissue repair processes are slower.

Nutrition can partially offset this extended recovery window. The immediate post-run nutrition window (30–60 minutes after a hard effort or long run) becomes more important, not less, for masters athletes. A 30–40g protein source alongside carbohydrates in this window provides the amino acid availability the body needs to begin repair at the moment when repair machinery is most active.

Anti-inflammatory foods become more relevant for masters athletes: omega-3 fatty acids from oily fish, flaxseed, and walnuts; polyphenol-rich foods including berries, cherries (particularly tart cherry concentrate around hard training), green vegetables, and olive oil. None of these are magic bullets, but consistently including them in the diet supports the recovery process that determines whether an athlete can train consistently across weeks and months.

Bone density: a nutrition priority many masters runners overlook

Running is a high-impact sport that stimulates bone formation when the athlete is adequately fueled. However, masters runners — particularly female runners post-menopause — face increasing bone density loss that running alone does not fully offset. Nutritional support for bone health becomes an active priority after 40.

Calcium intake: 1000–1200mg per day depending on age and sex. Food-first sources are preferable (dairy, fortified plant milks, leafy greens, sardines with bones), with supplementation used to close gaps when dietary intake is insufficient. Vitamin D is the co-factor that enables calcium absorption — many athletes are deficient, particularly those training indoors or in northern latitudes. Vitamin D testing and supplementation if deficient is one of the highest-value interventions available to masters athletes.

Adequate total calorie intake also protects bone. The relative energy deficiency syndrome (RED-S) — where training energy expenditure consistently exceeds energy intake — impairs bone metabolism in athletes of all ages, but the consequences are most serious in masters athletes where bone density is already declining with age. Masters runners who are trying to lose weight while training heavily should do so with professional guidance to avoid inadvertently accelerating bone loss.

Practical adjustments for the masters runner week

Three changes that produce the greatest benefit for most masters runners: (1) Deliberately increase protein per meal — add a protein source to any meal that currently lacks one, and accept that the per-meal portions will be larger than those recommended for younger athletes. (2) Take post-run nutrition seriously — do not skip or delay the recovery meal after hard sessions; the window matters more with age, not less. (3) Check vitamin D status — a simple blood test can confirm whether supplementation is needed, and deficiency is common enough in this population to make testing worthwhile without a specific symptom trigger.

What does not change with age: the importance of carbohydrates for fueling quality training, the value of consistent eating patterns, the relevance of adjusting intake to training load, and the fundamentals of hydration and electrolyte management. The adjustments are targeted — primarily protein upward and recovery nutrition more deliberate — not a wholesale overhaul of a nutrition system that has worked.