Eating for cycling after 40: what actually changes

Most nutrition advice aimed at older riders starts from the wrong place. It assumes that because a lot changes physiologically after 40, a lot must change on the plate. In practice the list of genuine, well-evidenced dietary differences is short — one of them is important, two are worth acting on, and the rest of the noise is people selling supplements to a demographic with money.

The short list is this. You need more protein per meal to get the same muscle-building response. Your bones deserve attention that a younger cyclist can postpone. You cannot trust thirst as much as you used to. And the risk of quietly eating too little goes up, because appetite drifts down while training volume does not.

Everything else that matters — total energy, total protein, carbohydrate matched to the work, consistency — is the same as it was twenty years ago. If you want the training side of ageing, cycling as you age covers what happens to your intervals and your recovery. This piece is only about food.

Anabolic resistance, and the number that comes out of it

Feed a young adult 20 g of high-quality protein and muscle protein synthesis rises to close to its maximum. Feed the same 20 g to a 70-year-old and the rise is smaller. The muscle is less sensitive to the signal — this is what anabolic resistance means, and it has been demonstrated with stable isotope tracers in enough separate laboratories that it is no longer in doubt.

The useful version of the finding is expressed per kilogram of body mass, because it has to be. The meta-regression that pooled the dose-response data put the protein dose needed to maximise myofibrillar protein synthesis at roughly 0.24 g per kg per meal in younger adults and roughly 0.40 g per kg per meal in older adults, with a wide upper confidence bound suggesting some older individuals need more still.

For a 75 kg rider that is the difference between 18 g and 30 g in a sitting. Not enormous. But it is the difference between a bowl of porridge with a splash of milk and a bowl of porridge with milk, yoghurt and a scoop of whey — and repeated four times a day, over years, it is the difference between holding lean mass and losing it.

Leucine, and why distribution beats the big dinner

The trigger for the synthesis response is not protein in general but the essential amino acids, and leucine in particular. Older muscle appears to need a higher leucine content in a meal to cross the same threshold — around 2.5–3 g of leucine per meal is the figure most often used, against something closer to 2 g in younger adults. In practice that maps onto the same advice: a bigger, complete protein serving at each meal, from a source with a decent leucine fraction. Dairy, eggs, meat and fish do this easily. Plant sources need either more volume or more variety.

Distribution matters independently of total. In a controlled trial, eating roughly 30 g of protein at each of three meals produced about 25% higher 24-hour muscle protein synthesis than the same daily total skewed towards dinner — 10 g at breakfast, 16 g at lunch, 63 g in the evening. The skewed pattern is the normal Western one. It is also, roughly, how most cyclists eat.

The fix is unglamorous: front-load. Most masters riders do not need more protein at dinner. They need 25–30 g at breakfast, which is where almost everyone is short. The post-ride protein question covers the basics of timing and sources; the change after 40 is the size of each serving, not the principle.

Four meals at 0.4 g per kg gives a 75 kg rider 120 g a day, which is about 1.6 g per kg — the bottom of the range recommended for athletes generally, and a sensible floor for an older one. There is no evidence that going much above roughly 2.2 g per kg does anything more, and the practical ceiling is usually appetite rather than physiology.

Bone, and the cycling problem

Cycling is the wrong sport for your skeleton. It is non-weight-bearing, it involves very little impact, and long rides in heat lose calcium through sweat. The consequence shows up in the data: highly trained male master cyclists have been found to have low bone mineral density relative to age-matched norms, and in a seven-year longitudinal study master cyclists lost lumbar spine density while non-athlete controls did not.

The dietary side of the response is unfussy. Around 1000–1200 mg of calcium a day, mostly from food, and adequate vitamin D. The reference intake for vitamin D sits at 600 IU a day up to age 70 and 800 IU above it, with a tolerable upper intake level of 4000 IU — a level worth knowing, because high-dose supplementation has not been shown to help bone. In a three-year randomised trial in healthy adults aged 55 to 70, the groups taking 4000 and 10,000 IU a day lost more radial bone density than the group taking 400 IU. More is not better here.

The non-dietary part matters more than the dietary part, and it is the reason this section exists in a nutrition article: calcium and vitamin D support bone that is being loaded. If nothing loads it, they have limited raw material to work with. Strength training for cyclists is, for a masters rider, at least as much a bone intervention as a power one.

Hydration, because thirst is less reliable now

Thirst sensation declines with age, and after a period of fluid loss older adults replace less of it spontaneously than younger ones do. Renal water conservation is also less efficient. None of this is dramatic on a two-hour ride in March. It becomes relevant on a long hot day, where a younger rider drinking to thirst will land roughly right and a 60-year-old doing the same may not.

The practical adjustment is modest: on rides over about two hours in heat, drink to a plan rather than to sensation — a bottle every 45 to 60 minutes as a starting point, adjusted by what the scales say afterwards. How much should you actually drink covers how to work out your own sweat rate, which is a better method than any table.

The failure mode nobody talks about

The most common serious nutrition problem in masters cycling is not too much of anything. It is too little.

Training volume in this group is often high and stubbornly protected — it is frequently the thing people are proudest of. Appetite, meanwhile, tends to drift down with age. Add a vague ambition to be a bit lighter for the hilly sportive in June and you have the conditions for low energy availability: enough food to get through the day, not enough to support training on top of basic physiology.

The consequences are well catalogued, and bone, hormones and immune function are all on the list — which in an older rider stacks on top of risks that are already rising. The signs are ordinary enough to miss: power that will not come back after a rest week, sleep that has got worse, recurrent minor illness, a resting heart rate that has crept up. Low energy availability and REDs goes through it properly, and it is the piece to read if any of that sounds familiar.

What actually changes, in one place

What to actually do about it

• Set a per-meal protein floor of 0.4 g per kg and hit it four times a day. Fix breakfast first — that is where the gap almost always is.
• Do not skew protein to the evening. Even distribution is worth roughly a quarter more daily synthesis for the same total.
• Take carbohydrate seriously when days are stacked. 1.0–1.2 g per kg per hour for the first few hours after a hard ride when the next hard ride is tomorrow, and 6–10 g per kg across a normal training day.
• Calcium 1000–1200 mg a day, vitamin D at the reference intake, and lift something twice a week. The third item is doing most of the work.
• Drink on a schedule in the heat, and weigh yourself before and after a long ride occasionally to calibrate.
• Watch total energy, not body mass. If training volume has held steady and the scales are moving down without you trying, that is information, not success.

The honest summary is that a well-fed 55-year-old cyclist and a well-fed 25-year-old cyclist eat remarkably similar diets, with one meaningful difference in the size of each protein serving and rather more attention paid to bone. Most of what is sold as masters-specific nutrition is the ordinary advice with a higher price and a photograph of someone with grey hair on the tub.