I don’t think there is one best diet. Anyone who tells you there is probably has something to sell you. What interests me more is which rules actually survive real life. Most diets don’t fail because the idea was wrong. They fail because people can follow them for three months, maybe six, and then life happens. Travel, work, family, a bad week, a restaurant, whatever. Even the newer weight-loss drugs are interesting in this way, because a big part of what they do is simply make people less hungry. They don’t teach anyone how to eat for the next twenty years. The difficult part is still the same as it always was: doing something consistently for a very long time. That’s the part nutrition for endurance training rarely accounts for.

What follows is what I actually eat now, four months into building toward an Ironman, including the parts that don’t work particularly well.

What Changed When Summer Ended

Summer changing into autumn has already changed my eating more than I expected. The heat was forcing me to train very early, and anyone who has tried running properly at five in the morning knows the problem: there isn’t really time to eat a normal breakfast, wait for it to digest, and then run before the day starts. So you end up with a gel, a sugary drink, or nothing. For years there was a lot of talk about fasted training being good for fat metabolism. I think it’s the wrong approach for age-group athletes. It’s very hard, maybe impossible, to do quality sessions day after day when the body has already been starved for ten to fourteen hours before you start.

Now the mornings are cooler and I can eat before training again. Breakfast is still very early, usually before half past six, but it can be actual food. Mostly carbohydrate, often bread I baked myself or some cereal, some dairy for protein, fruit, sometimes even vegetables. I don’t start the first session until after eight, so there’s enough time for it to settle.

Fuelling Through the Session

What I eat during the session depends mostly on what I’m doing. Somewhere between thirty and sixty minutes in, I’ll start on the usual sports food — gels, isotonic drink, bars, banana, sometimes jelly beans. If I’m running first, which is most days, I’ll usually eat something more solid before getting on the bike, keep the first hour fairly easy so the food settles, then go back to gels and whatever else I’m carrying. After a long session, if I’ve eaten properly during it, I don’t need to attack a huge meal the second I get home, but I still get some carbohydrate and protein in fairly soon — around four parts carbohydrate to one part protein, within half an hour, because that’s what supports the recovery.

Later in the day I move away from the simple carbohydrates and toward protein and fat — meat with some whole grains, beans, or one of the higher-protein dairy things. I wouldn’t necessarily eat some of those products if I wasn’t training this much, since they carry plenty of calories of their own. On normal days I stop eating properly around four or five in the afternoon, and anything later is small.

Heavy Weeks and Light Weeks

A two-hour training day and a five-hour one are not the same thing. When I train more, I eat more, and a lot of the extra food simply happens on the bike rather than at the table. On heavy weeks I push protein up, because I don’t want to lose muscle while doing all that endurance work. On easier weeks I eat more fruit and vegetables and a little less overall, partly because I don’t need the calories and partly because I like to think I’m doing something useful for my gut. Timing changes too. A five-hour session moves the whole day around, and I don’t want a large amount of fat or protein sitting in my stomach three hours before bed.

I don’t count grams. I could calculate a theoretical number for all of it, but I’m not convinced the precision is as useful as people make it sound. I do know that a normal restaurant portion of meat, maybe 150 or 200 grams, doesn’t get me particularly far on a heavy training week. Travelling makes this harder, because I can’t cook the way I do at home. I eat as much protein as I reasonably can and still usually end up below where I’d want to be for my body weight, then make some of it back in the first few days after getting home.

The Rule That Stayed, and the One That Didn’t

The one rule I’ve actually kept for about ten years is simple: after training, carbohydrate and protein within roughly thirty minutes. I’ve tried most of the other things at some point — fasted training, low fat, high fat, elimination diets when my gut or skin was acting up — and eventually dropped all of them. This one stayed because it’s easy. I finish training, I eat. I don’t have to think about it very much.

The rule I dropped, and probably shouldn’t have, was keeping sugar low outside training. It worked well at home and fell apart almost immediately once I started travelling. Away from my own kitchen it’s very easy to have sweetened dairy, coffee with too much honey, or coffee and a few biscuits after a ride because they happen to be there. Those processed things are my quiet cheat. I just still prefer food where I can read the ingredient list and recognise most of what’s in it.

What Six Months of Elimination Taught Me

The elimination diets are the clearest example of the gap between something that works and something you can live with. Cutting milk and wheat made a real difference to my gut. I kept it up for half a year. It did nothing for the skin problem I was actually trying to fix — that took a specialist, not a food diary — and it became such a pain to maintain that I eventually stopped. If something only works while life is perfectly controlled, it isn’t a very useful solution.

I studied nutrition as part of both my cycling trainer and my fitness and rehabilitation qualifications, and I’ve spent a few decades testing it on the only subject I have unlimited access to. Most of what that gave me is negative knowledge. We know reasonably well what the bad end of the spectrum looks like. Less processed food with ingredients you can recognise is a decent place to start. Almost everything past that depends on the person: a few reliable meals you know work, and the rest changing with the season and the training.

Frequently asked questions

Is fasted training useful for endurance athletes?
It’s debated. The theoretical case is improved fat metabolism, but for age-group athletes training several hours a week, starting quality sessions underfuelled after ten or more hours without food makes it harder to hit the intensity those sessions require. Many coaches now favour fuelled training for most sessions.

How soon after training should you eat?
Research generally supports eating carbohydrate and protein within roughly thirty minutes to an hour after training, when the body is most receptive to replenishing glycogen and beginning muscle repair. The precise window is less rigid than it was once presented, but eating reasonably soon still helps.

How much protein do endurance athletes need?
Requirements vary by body weight, training load, and individual factors, and exact daily needs are difficult to measure precisely. What’s more practical to notice is that standard restaurant portions of meat — 150 to 200 grams — typically fall well short of what a heavy training week requires.

Do elimination diets work?
They can identify genuine food sensitivities and sometimes produce real improvements, particularly for digestive symptoms. They’re also difficult to sustain long-term, and they aren’t a substitute for medical diagnosis when the underlying problem is something else. Anyone considering one should speak with a doctor first.