Why are footballers so lean?

Stand pitchside during the warm-up and you notice it immediately. Shirt sleeves pulled back, arms and legs with almost no soft tissue — these are people whose bodies have been shaped by an unusual combination of relentless physical work and tightly controlled eating.

The work comes first. A top-flight player covers 10 to 13 kilometres in a single match, and that distance is not a steady jog. It is a mix of walking, running, sprinting, changing direction, jumping and bracing against opponents. Do that once or twice a week across a long season and the body has almost no opportunity to store fat. The energy demand is simply too high.

Training days add to it. Matches are the most visible part of a player's week, but the sessions in between — technical drills, tactical shape work, gym sessions, recovery runs — mean the body is rarely idle. The total energy burned across a week at a top club is enormous, and the body responds by stripping away anything it does not need to carry.

Diet is the other half. Club nutritionists set out exactly what players eat, when they eat it, and in what amounts. Protein is kept high to maintain and repair muscle. Carbohydrates are timed carefully — more before and after training, less on rest days — so the body has fuel when it needs it and does not store the surplus. Processed food and alcohol are kept to a minimum or cut out entirely. Players are not just eating less of the wrong things; they are eating the right things at the right moments, which is a different discipline altogether.

The result of those two forces working together — constant high-intensity movement and precise nutrition — is a body that carries very little fat and a great deal of functional muscle. Neither factor alone would produce what you see on the pitch. A person who runs 10 kilometres a day but eats poorly will not look like a professional footballer. A person who eats a perfect diet but sits still will not either. It is the combination, sustained over years, that does it.

The edge most people do not think about is how much of this starts young. Players who reach the top flight have usually been in academy systems since their early teens, meaning their bodies developed under professional guidance during the years when habits and physiology are most easily shaped. By the time they appear on a Premier League or La Liga pitch, the leanness is not something they have recently achieved — it is the only physical state they have ever known as adults.