Eating around training: what the timing actually changes

Sports nutrition advice tends to arrive with more certainty than the evidence supports. The useful summary is short: total intake over the day matters most, timing matters at the margins, and the margins get wider the harder and more often you train.

The protein window is wider than advertised

The idea that muscle protein synthesis collapses thirty minutes after a session has not held up well. Current reviews point to a window of several hours, and to daily total as the dominant factor — roughly 1.6 grams per kilogram of body weight per day for people training seriously, spread over three or four meals. For someone training once a day, sprinting to a shake in the changing room changes very little.

Where timing does matter: training twice in one day, or training fasted in the morning with a competition in the evening.

Carbohydrate is about duration, not intensity

Below about sixty to ninety minutes, stored glycogen covers the work and eating during the session adds nothing but comfort. Beyond that, intake during exercise starts to matter, and beyond two hours it becomes decisive. That is why the advice for a parkrun and for a marathon looks so different despite both being running.

What to eat before

• Two to three hours out: a normal meal with carbohydrate, moderate protein, low fat and low fibre.
• Thirty to sixty minutes out: something small and simple — a banana, a slice of bread with honey.
• Fat and fibre close to a session are the most common cause of stomach trouble, not the food itself.

Fluids, briefly

Drink to thirst for anything under an hour. Beyond that, and especially in heat, sodium starts to matter as much as water. Weighing yourself before and after a long session is the cheapest way to learn your own sweat rate, and it is more useful than any general recommendation.

Planning the week rather than the meal

Most people get more out of arranging their training week sensibly than out of optimising a single meal. Knowing what pace a session should be run at, and therefore how long it will last, decides whether fuelling during the session is relevant at all — a pace calculator for planning sessions is a plain way to work that out beforehand.

For the wider context, from race reports to training material, a sports desk with training tools alongside the results keeps both in one place. The nutrition question is nearly always downstream of the training question: settle the session first, and the food follows.