A full meal two to three hours before, only something small close to the start: the timing ladder for a full tank without a heavy stomach — plus the exception.
The honest answer first: the closer the meal sits to your session, the smaller and more carbohydrate-focused it has to be. A full meal fits two to three hours beforehand, and 30 to 60 minutes before the start only something small. And if you ate properly beforehand, you have already half-answered the question of what to eat afterwards: the relevant window around your session runs more like four to six hours, not 30 minutes [1].
A meta-analysis on protein timing confirmed it from the other side: protein before training worked just as well as protein after — and the timing effect largely disappeared once total daily intake was accounted for [2]. So the meal beforehand is not a warm-up act. It is already part of the session.
What no study can settle for you is the second half of the question: what does your stomach tolerate under load? That is as individual as your shoe size, and the only way to find out is to try it — in training, never on race day.
This ladder is practical experience from nutrition coaching, not a study figure — but it works for most people straight away:
Rule of thumb: the less time is left, the less work your stomach should get. Under load, blood moves into the working muscles — and is then missing exactly where digestion happens.
Carbohydrates are the lead role here, because they fuel hard intervals and heavy sets: rice, potatoes, pasta, bread, oats.
Add a portion of protein. The position stand of the International Society of Sports Nutrition names 20 to 40 g per serving, or 0.25 g per kilogram of body weight [5] — at 75 kg that is roughly 19 to 30 g, so a tub of skyr, three eggs or a palm-sized piece of chicken.
What you deliberately keep small: fat and fibre. Both slow gastric emptying, and a full stomach during sprints is not a training stimulus, it is a brake. The creamy sauce gets its moment after training, not before. Where exactly your limit sits is not in any table — that is practice, and it differs from person to person.
The closer you get to the start, the simpler it gets. What almost always works in practice: a banana, a rice cake with honey, white bread with jam, dried fruit, a mouthful of diluted juice.
What almost never works: anything high in fat (nuts, cheese, chocolate bars), anything high in fibre (wholegrain, pulses, raw vegetables) — and anything you have never eaten before.
A fluid loss of more than 2 % of your body mass impairs aerobic performance, especially in the heat, and even 1 % increases the strain on your cardiovascular system [3]. At 75 kg, 2 % is just 1.5 kg — you can sweat that off in a good hour on a warm day.
Even so, you do not have to calculate how much to drink beforehand. The safest strategy is remarkably simple — and it is a practical rule, not a study figure: before, during and immediately after exercise, drink when you are thirsty. Pouring litres in as a precaution is not a safety measure, it is a risk of its own.
Then you train fasted, and that is fine. A systematic review with meta-analysis found no additional effect on fat mass when sessions were done fasted rather than fed [6]. So it gives you no advantage — but on short, easy sessions it does no harm either.
In practice: up to about an hour of easy work you need nothing in the morning but water. If the session gets long or hard, put something small in — a glass of juice, a banana, a few sips of sports drink.
This guide explains and motivates; it does not replace medical or dietary advice. Anyone with diabetes, on blood-glucose medication, living with reflux, irritable bowel syndrome or another gastrointestinal condition, pregnant or breastfeeding, should plan meals around training with professional support.
Nausea, dizziness or a racing heart during a session are not toughness tests, they are stop signals. Stop, drink and eat something — and if it comes back, get it checked medically.
One point that often sits underneath this topic: if you deliberately eat nothing before training so as not to "undo the calories", that is not a training plan, it is a warning sign. Persistent fatigue, constant cold, a missing period or recurring infections belong in a doctor's hands. And if thoughts about food start running your day, talk to a registered dietitian.
Build three fixed pre-training meals and repeat them until they are boring: one for "three hours of time", one for "one hour of time", one for "twenty minutes of time". You never need more than that.
The effect is bigger than it sounds. With every session you collect data on your own tolerance instead of guessing again — and on race day you fall back on something that has worked ten times. That is exactly what the IOC consensus statement recommends for anything used in competition [4].
In practice a full meal sits best two to three hours beforehand, with a small carbohydrate-focused snack still fine 30 to 60 minutes before the start. Time pressure is no drama here: the relevant window around the session runs more like four to six hours [1], so you do not have to hit it to the minute.
For an easy session of up to about an hour, water is enough. If it gets longer or intense, something small and fast helps: a banana, a glass of juice, white bread with honey. Training fasted brings no extra fat loss [6] — it is a question of convenience, not of effect.
Close to the start the banana almost always wins: quickly available, low in fat, low in fibre. Bars vary enormously — the sports bar with dextrose works, the nutty wholegrain bar sits heavy. "Nothing at all" is a perfectly legitimate option for short, easy sessions.
Usually it is the composition rather than the timing: too much fat, too much fibre, or simply too big a portion. Nerves and high intensity slow digestion too. Cut fat and fibre first, then the amount — and always test changes in training, never in competition [4].
Fasted Training: Does It Really Burn More Fat?