Why Injuries Linger in Your 40s (and What Actually Changes)
The short answer: Injuries often feel slower to settle in your 40s, but the research does not show a simple age switch that makes tissue stop recovering. What usually changes is how much load you recover from, how consistently you train, and how much strength you have in reserve.
- A 2026 systematic review found muscle stiffening with age is not inevitable in healthy people.
- Lingering injuries in your 40s are more often about load, sleep, stress and lost strength than “old tissue”.
- Resistance training is linked to better joint flexibility, and age did not change that effect in a 2025 meta-analysis.
- Rest alone rarely fixes it. A graded plan that rebuilds capacity usually does more.
A patient in her mid-40s asked us recently: “I did the same weekend run I always do. Why is my calf still grumbling three weeks later?” It is one of the most common questions we hear from active adults, and the honest answer is more hopeful than “it’s just age”.
Do injuries really heal slower after 40?
Many people notice it, and we do not dismiss that. But we cannot point to a single research finding that says tissue stops healing at 40.
What the evidence supports is a gradual, individual picture. Some people recover quickly well into their 50s. Others feel stuck at 38. Training history, sleep, stress and general health all play a part.
Does tissue automatically get stiffer and more fragile with age?
A common belief is that collagen, the protein in muscle and tendon, builds up and stiffens everything as we age. A 2026 systematic review in the American Journal of Physiology: Cell Physiology looked at this in people. It covered nine studies, with 122 younger and 119 older adults over 60.
Four studies found no age difference, four found more collagen, and one was unclear. The better-controlled studies tended to find no difference. The authors concluded this build-up is not an inevitable part of ageing, and may reflect other health and lifestyle factors.
One honest limit: those studies were in people over 60, so this tells us about the direction of travel, not about 43-year-olds specifically.
So what does change in your 40s?
Your life changes more than your tendons do. Work is busier, sleep is lighter, and training often becomes squeezed into one big weekend session. That is a recipe for load spikes, which our runner’s guide to bone, tendon and niggles explains.
Strength reserve also matters. If you stopped lifting years ago, your tissues may simply have less capacity than your activity now asks for. Capacity is something you can rebuild.
Why does rest not fix it?
Rest settles pain, but it does not rebuild capacity. Many people rest for a few weeks, feel fine, return to full load, and flare again.
Tendons in particular tend to respond to progressive loading rather than long rest. We cover that in our guide to heavy slow resistance for tendon pain.
Does strength training help with stiffness?
A 2025 meta-analysis in the Journal of Strength and Conditioning Research pooled 36 studies and 1,469 healthy adults. Resistance training was linked to better joint flexibility than no training. Age did not significantly change the effect, and higher-intensity programmes did better than lower-intensity ones.
There are caveats. None of the studies were rated low risk of bias, and the results varied a lot between studies. So it is encouraging, not a promise.
What does a smarter comeback look like?
It starts by working out what is actually sore, and what load it can tolerate today. From there, the aim is to rebuild strength around the area, then lift the load back up in steps. Our post on power and strength after 45 shows why this matters beyond injuries too.
For women in this age group, bone and hormone changes are part of the picture. See our perimenopause bone-density guide. Where it helps the plan, we can also use force-plate testing to check strength and left-right differences. You can read more on our force-plate testing page.
When should you get it checked?
If an injury has lingered for more than a few weeks, keeps flaring when you return to training, or is changing how you move, it is worth a proper look. Working out why it keeps stalling is the kind of work our team does every week with active adults across Logan.
You can book an appointment online at our booking page, or call reception on 07 3209 2000 and tell them what you are trying to get back to. We are Daisy Hill Physio, U4 11-13 Allamanda Dr, Daisy Hill QLD 4127, in Logan, south of Brisbane, Queensland (not Logan, Utah).
This article is general information, not a diagnosis. If you have severe pain, cannot bear weight, or notice numbness, weakness or pain at night, seek medical care promptly.
Reviewed by Teya Williams, physiotherapist at Daisy Hill Physio, whose focus includes healthy ageing and strength training.
Sources: Schweitzer AM, Abercrombie MJ, Losciale JM, Mitchell CJ. Muscle collagen accumulation is not a universal feature of human aging: a systematic review. Am J Physiol Cell Physiol 2026;330(5):C1207-C1219. doi:10.1152/ajpcell.00789.2025. Favro F, Roma E, Gobbo S, et al. The influence of resistance training on joint flexibility in healthy adults: a systematic review, meta-analysis, and meta-regression. J Strength Cond Res 2025;39(3):386-397.
