The cycling internet sells every rider the same nutrition advice, regardless of age: eat less, ride more, get lighter, go faster. For a twenty-five-year-old it's incomplete. For a fifty-year-old it's actively harmful. The metabolism you're feeding at fifty does not respond the way it did at thirty, and the single biggest change has a name most amateurs have never heard — anabolic resistance.
This article is part of our masters nutrition hub. The point here is to explain what actually changes after 40, and why the answer is more protein and better fuelling, not the restriction the internet keeps prescribing.
What anabolic resistance actually is
When you eat protein and train, your body switches on muscle-protein synthesis — the repair-and-build process that turns training stress into adaptation. The switch is sensitive to a single amino acid, leucine, and to the size of the protein dose. Here's the part that matters: with age, that switch gets harder to flip. The same meal, the same session, produces a smaller building response than it did decades earlier. Professor Stuart Phillips' research on protein metabolism has mapped this in detail — older muscle needs a bigger stimulus to mount the same response.
That one fact rewrites the rules. The masters rider who cuts food to lose weight isn't trimming fat in some neat, targeted way. In a steep deficit the body takes muscle alongside fat, and anabolic resistance makes that lost muscle slow and stubborn to rebuild. You don't get lighter and faster. You get lighter and weaker — the muscle that holds your power, gone, and harder to win back than it was to lose.
The protein dose went up, and so did the timing
The practical answer is a higher protein target, eaten differently. Where a younger rider might maintain on around 1.4 g/kg a day, masters cyclists do better at 1.6 to 2.2 g/kg/day — and the distribution matters as much as the total. Four feedings of 30–40g beat the same amount stacked into one big dinner, because each feeding needs to clear the leucine threshold to switch synthesis on, and that threshold is higher than it used to be. Three meals a day leaves long anabolic gaps; four evenly spaced feedings keep the signal firing. How much protein cyclists actually need breaks the targets and timing down in full.
One feeding earns its place more than any other after 40. Dr Michael Ormsbee's work on 40 grams of protein before bed targets the overnight repair window — a long fasting stretch where anabolic-resistant muscle is most exposed. A slow-digesting protein like casein, taken in the 30 minutes before sleep, feeds synthesis through the night. It's the lever most amateurs skip and the one the masters metabolism needs most.
Registered dietitian Alex Larson makes the same case from the body-composition side: in getting lean and staying lean, the recurring finding is that under-eating sabotages the very leanness riders are chasing. Protect the muscle, fuel the training, and the fat takes care of itself.
Resistance training is the other half of the prescription
Nutrition doesn't work in isolation here. Anabolic resistance applies to the training stimulus too, which is why loaded resistance work becomes non-negotiable for masters cyclists rather than optional. The goal is to challenge the muscle hard enough to demand it stays — leg-press and single-leg patterns, hip and posterior-chain work, loaded in a controlled rep range two or three times a week. The food and the loading are a pair: the protein supplies the bricks, the training tells the body to lay them. Skip either and anabolic resistance wins by default.
Stop chasing the scale
The deeper shift after 40 is the metric itself. Bodyweight is a crude, often misleading proxy for what makes you fast. Body composition — how much of you is muscle versus fat — is the number that actually determines how you climb. Why "lighter is faster" is holding you back makes the case that the scale lies, and Dr David Dunne, who has fed World Tour riders, explains in why most cyclists get race weight wrong how the lighter-is-faster framing manufactures the problem it claims to solve.
The masters position is the opposite of restriction. You eat to hold muscle, to fuel your sessions, and to recover faster — and the leanness follows as a by-product rather than a target you starve yourself toward. It pairs directly with the training in our VO2max for masters hub: the protein protects the engine, the intervals build it.
The metabolism changed. The honest response isn't to eat less. It's to eat smarter, protect what makes you strong, and stop treating your own muscle as something to be dieted away. You're not done yet.