Inflammation and Sport: How Diet Affects Recovery and Performance
Inflammation has a terrible reputation among endurance athletes, and most of it is undeserved. Every hard session you do — a threshold block on the turbo, a hilly 20-miler, a race you went too deep in — creates mechanical damage to muscle fibres and triggers an immune response to clean it up. That response is the repair process. Interleukin-6 can rise anywhere from 10 to 100-fold after a marathon, creatine kinase typically peaks somewhere between 24 and 48 hours after the effort, and you feel stiff and heavy for a couple of days. None of that is a malfunction. It is your body doing exactly what it should.
The problem is not inflammation itself. It is inflammation that never resolves — the low-grade, weeks-long version that builds when training load outstrips recovery, sleep is short, and the diet underneath it all is thin. That version doesn't help you adapt; it just costs you sessions. This guide looks at what the research actually says about inflammation in sport, how diet and recovery interact, and what to change if you keep turning up to Tuesday's intervals still carrying Sunday's long run.
Acute Versus Chronic: Two Very Different Things
Acute exercise-induced inflammation is short-lived and useful. Muscle damage from eccentric loading — the braking action of running downhill, or holding a big gear on a climb — causes micro-tears. Neutrophils and macrophages arrive, clear the debris, and satellite cells rebuild the fibre slightly more robustly than before. Peak soreness lands 24 to 72 hours later. That's DOMS, and it resolves.
Chronic, systemic inflammation is a different animal. It shows up as C-reactive protein that stays elevated between sessions, a resting heart rate that has crept up 5-8 beats, poor sleep quality, and a persistent sense that your legs never quite come back. In endurance athletes it is usually driven by a combination of high training volume, energy availability that is too low for the work being done, disrupted sleep, and a diet that is heavy on refined carbohydrate and light on polyphenols and omega-3 fats.
The practical distinction matters because the interventions are opposite. You do not want to blunt the acute response — that's the adaptation signal. You do want to support the resolution of it, and you want to avoid the background inflammatory load that stops resolution happening.
Inflammation, Sport, Diet and Recovery: What the Food Actually Does
Three dietary levers have reasonable evidence behind them, and they are not the ones most athletes reach for first.
Carbohydrate during and after exercise. This is the most underrated anti-inflammatory intervention in endurance sport. Exercising in a glycogen-depleted state amplifies the cortisol and cytokine response substantially. Taking on 60-90g of carbohydrate per hour during long efforts measurably reduces post-exercise IL-6 and cortisol compared to riding or running fasted. If you routinely do three-hour sessions on a bottle of water and a cereal bar, you are creating an inflammatory load you then have to recover from.
Polyphenols, particularly anthocyanins. Montmorency tart cherries are the most studied option in this space. They are dense in anthocyanins — the same pigments that give the fruit its deep colour — which have both antioxidant and anti-inflammatory activity. The well-known London Marathon study by Howatson and colleagues gave runners tart cherry concentrate for five days before and two days after the race. The cherry group recovered isometric strength faster and showed lower IL-6, CRP and uric acid than placebo. Follow-up work in cyclists has shown similar patterns across three-day simulated race blocks.
Omega-3 fatty acids. EPA and DHA are incorporated into cell membranes and shift the balance of signalling molecules produced during the inflammatory response. Doses in the research typically sit around 2-3g of combined EPA and DHA daily. Two portions of oily fish a week gets most people partway there; genuinely high intakes usually need supplementation.
The Antioxidant Timing Trap
Here is where a lot of well-intentioned athletes go wrong. If some antioxidant support is good, more must be better — so they take high-dose vitamin C and E year-round.
The evidence says don't. Paulsen and colleagues gave trained subjects 1000mg of vitamin C and 235mg of vitamin E daily through an 11-week endurance programme. The supplemented group showed blunted increases in markers of mitochondrial biogenesis compared to placebo. The reactive oxygen species produced during training are part of the signal that tells your muscles to build more mitochondria. Mop them all up indiscriminately and you dampen the adaptation you trained for.
The sensible approach is periodisation. Through heavy training blocks where adaptation is the goal, get your antioxidants from whole foods and keep megadose supplementation out of it. Around races, multi-day events, and back-to-back competition where recovery speed matters more than adaptation, that is when concentrated polyphenol support earns its place. Understanding how inflammation, sport, diet and recovery fit together is mostly about knowing which of those two phases you are in.
The Boring Foundations That Beat Any Supplement
None of the above works if the basics are missing. Aim for 7-9 hours of sleep — growth hormone release and the bulk of tissue repair happen there, and a single night at five hours measurably raises inflammatory markers. Eat enough: relative energy deficiency is one of the most reliable ways to keep CRP elevated in an endurance athlete. Get 20-40g of quality protein within a couple of hours of finishing a hard session, roughly 0.3g per kilogram of body weight. Hit 8-10 portions of fruit and vegetables daily for a broad polyphenol base rather than relying on one hero ingredient.
What We Use at FTP Endurance Fuel
We built our pastilles around this exact logic. The fuelling job and the recovery job are related, and they can be solved with the same product if you get the formulation right.
Our Tart Cherry Pastilles use real Montmorency tart cherry for the anthocyanin content, paired with a 1:1 glucose-to-fructose carbohydrate blend that lets you absorb closer to 90g per hour rather than the ~60g ceiling you hit with glucose alone. That means you are hitting the carbohydrate lever during the session and the polyphenol lever at the same time, without carrying a separate recovery product. During heavy training blocks we use the Mixed Fruit Pastilles for straightforward fuelling and save the tart cherry for race weeks and back-to-back days, which lines up with the periodisation logic above.
They come in 1kg bulk pouches because a resealable pouch you decant from is cheaper per gram and produces far less packaging waste than individually wrapped sachets — and because a real recovery strategy is something you do consistently for months, not once before an A-race.
If you want to test the approach before committing to a kilo, the Taster Pack is the sensible starting point. Run it through a proper training block — two or three weeks of your normal load — and pay attention to how your legs feel on the second hard day of the week. That's where the difference tends to show up first.
