Carbohydrate around training: what it is actually for

Resistance training draws heavily on stored muscle glycogen. A hard session can meaningfully deplete it, particularly with high volume, short rests and sets in the moderate to high rep ranges.

Which makes carbohydrate the fuel that most directly determines whether the last few sets of a session are any good.

How much, roughly

Recommendations for athletes vary with training load. For someone doing moderate resistance training several days a week, something in the region of three to five grams per kilogram of body weight per day is a common starting point. Higher training volumes, or concurrent endurance work, push that upward — endurance athletes in heavy training may need considerably more.

For an eighty-kilogram lifter training four or five times a week, that is roughly 240 to 400 grams a day. Which is a lot more than many people eat, particularly those who have absorbed the idea that carbohydrate is optional.

These are starting points, not prescriptions. Adjust based on performance, energy through sessions, and body composition goals.

Timing, honestly assessed

Before training. A meal containing carbohydrate one to three hours beforehand tops up liver glycogen and provides available fuel. For most people this is the timing that makes the most noticeable difference to how a session feels.

The optimal amount and timing is individual, largely determined by digestion. Some people can eat a full meal an hour before training; others need three hours or a smaller, simpler meal.

During training. For sessions under about an hour, unnecessary. For very long sessions, or double sessions, or endurance work, intra-workout carbohydrate has genuine support. For a normal hour-long lifting session it is a marketing opportunity rather than a physiological need.

After training. Glycogen replenishment matters most when you have another session within a few hours. If you train once a day, total daily carbohydrate intake replenishes stores comfortably before the next session, and the urgency of the post-workout window is overstated.

For twice-daily training or competition days, rapid post-session carbohydrate genuinely helps.

Type

Most daily carbohydrate should come from minimally processed sources — grains, potatoes, rice, oats, fruit, legumes — because they bring fibre, micronutrients and satiety with them.

Around training, faster-digesting and lower-fibre sources are more practical, simply because they sit better in the stomach. A large bowl of high-fibre food immediately before squatting is unpleasant for reasons unrelated to physiology.

Glycaemic index has been over-emphasised. In the context of a mixed diet with meals containing protein, fat and fibre, the differences largely wash out.

The low-carbohydrate question

Low-carbohydrate and ketogenic approaches work for some people for body composition, largely through appetite effects and adherence.

For high-intensity resistance training specifically, the evidence is less favourable. Glycogen is the primary fuel for repeated near-maximal efforts, and training in a chronically depleted state generally reduces training quality — fewer reps, lower volumes, worse sessions.

Some adaptation occurs over weeks, and it does not fully compensate for high-intensity work. If you want to train hard and often, carbohydrate is the pragmatic choice.

If you prefer a lower-carbohydrate diet for other reasons, that is a legitimate trade — but recognise that it is a trade rather than an optimisation.

The symptoms of not eating enough of it

Feeling flat and heavy in sessions despite adequate sleep. Volume dropping across a session more than usual. Recovery between sessions taking longer. Poor mood and irritability, which is a genuine and under-recognised effect. Waking during the night.

People frequently attribute these to overtraining or to a programming error and adjust the programme when the fix is dietary.

The practical version

Eat a carbohydrate-containing meal a couple of hours before training. Eat carbohydrate at most meals. Increase intake on high-volume days and reduce on rest days if body composition is a concern.

And if training feels consistently flat, try adding a hundred grams a day for a fortnight before restructuring your programme. It is a cheaper experiment and it is more often the answer.