Taller, leaner, faster. The age of those who win

A recent BBC Sport article reports on a study by Alan Nevill and colleagues on the evolution of body size, age and the use of substitutes in English football. Building on that work, the analysis is extended here by drawing in other studies and recent data, in order to connect the available evidence to the changes in the modern game. What emerges, for instance, is that top teams tend to field relatively younger players. But is it age, or economic value, that proves the stronger predictor of results?

Players’ body composition

Alan Nevill’s group compared the characteristics of players in the English top division across six sample seasons, one every ten years, from 1973-74 to 2023-24 (with age data from 1993-94 onwards)¹. Average height has risen by more than four centimetres between the 1970s and the most recent measurements. Body mass, which grew until the early 2000s, has instead declined over the last two sample seasons.

Players today present an on average taller, more linear and more angular profile. The study, however, measures body composition, not the qualities required to play at the highest level. Agility, motor control and perceptual capacities, for instance, fall outside its scope. Moreover, a predominantly ectomorphic somatotype cannot in itself be taken as a marker of superior performance. The trend, in any case, is not uniform across positions. Goalkeepers and defenders continue to grow taller; midfielders and forwards appear to have reached a plateau.

For defenders and goalkeepers, height may translate into greater spatial coverage and an advantage in aerial duels. Yet height alone is not enough: despite their stature, a defender must still be able to cope with the tight dribbling of more agile attackers, and a goalkeeper to perform the complex movements the role demands. What distinguishes elite athletes, after all, are factors that body composition alone cannot capture. This suggests that, in talent identification, assessment should not be limited to anthropometric characteristics alone. For those preparing athletes, meanwhile, strength work should not aim at building muscle mass as an end in itself, but should translate into qualities that serve performance and match the demands of the position.

A faster game

Many argue that the increase in the speed of play has gone hand in hand with advances in sports medicine, and therefore with the pursuit of ever greater athleticism. Whereas in the 1970s and 1980s, according to estimates from several studies, players rarely exceeded 30 km/h, at the 2022 World Cup at least ten ran faster than 35 km/h². More than the maximum figure, however, what seems to matter most is the quality of the running: not the isolated speed peak or total distance, but how — and how often — that effort is repeated. As Jens Bangsbo, physiologist at the University of Copenhagen, observes, the forward of the last century could walk for much of the match and explode in a handful of actions; a figure that today appears to have disappeared². UEFA data from Euro 2024 tell us that on average players produced running actions above the 25 km/h threshold around 12 times per match, with differences by position: 8 times for centre-backs and central midfielders, 12 for forwards, 14 for full-backs².

Modern measurements frequently record peaks above 35 km/h. Direct comparisons with the 1970s and 1980s should be treated with caution, however, since the measurement methods of that era were not comparable to today’s tracking systems.

Substitutions and coaching decisions

From a single permitted substitution in the 1970s to the five allowed today, the use of substitutions has grown as a result of regulatory change. In the aggregated data of Nevill and colleagues, the increased use of substitutes coincides above all with a reduction in appearances by defenders classified as first-choice players, more marked than that observed for midfielders and forwards. The authors draw from this the hypothesis that defenders are substituted more frequently¹. Why this happens, the study does not say. What follows is reasoning by hypothesis.

Nevill treats defenders as a single block, without distinguishing between centre-backs and full-backs: and it may well be full-backs who come off more often. Another study shows that most substitutions are “like for like” (full-back for full-back, midfielder for midfielder³). Not a reshaping of the setup, then, but a way of preserving the defensive structure. Full-backs, moreover, are among the positions that sprint most (UEFA data from Euro 2024 credit them with the highest number of actions above 25 km/h²) and therefore among the most exposed to fatigue. Replacing one with another full-back serves to put fresh legs into a high-intensity role. Verifying this would require event-by-event data distinguishing centre-backs from full-backs.

The other explanation relates to the scoreline. A defender may be withdrawn for a forward when chasing the game or, conversely, another defender introduced to protect a lead. On this the research is fairly clear: Wittkugel and colleagues find that more than half of defensive substitutions occur while winning, and more than half of attacking ones while losing³. There is, finally, one detail that says a great deal about coaching choices: top teams substitute less. Teams finishing in the top six use their first-choice players more often and rely less on the rest of the squad¹.

Does age matter, or squad value?

The study data show that teams finishing in the top six field players who are on average younger. The gap is small (25.8 years against 26.9 for teams from seventh place down). The finding is stable¹, but it does not prove that lowering squad age automatically produces better results. Analysing more than 16,000 Champions League players, Kalén and colleagues found no significant age differences between winners and non-winners⁴. What weighs most is squad value. In Gerhards and Mutz’s study, covering 60 seasons across 12 European leagues, market value emerges as the single most important predictor of performance; overall, the models analysed explain around two thirds of the variance in results. On 38 occasions out of 60 the title went to the most expensive team, 15 times to the second and 6 times to the third. Only one genuine outsider: Leicester in 2015/16⁵.

Stronger clubs, after all, have greater resources to identify, sign and retain young players who are either already ready for the top level or have high growth potential. PSG is one example: they won the 2025 Champions League with one of the youngest squads ever crowned European champions, while at the same time being among the most expensive in the world. Chelsea in 2025-26 offers a counterexample. Despite having one of the youngest squads and one of the highest estimated values in the Premier League, they finished tenth⁶.

The case shows that squad value is not a sufficient condition. What also counts is how far market value reflects the players’ actual quality, the balance of the squad, continuity, the coach’s work, injuries, and the ability to turn individual talent into collective performance.

Investing in young talent, like developing the academy, does not necessarily mean spending little. The economic advantage lies rather in the potentially longer span of performance, in room for growth, and in possible resale value. Seen this way, age would be a consequence of transfer strategy and academy work, rather than the cause of victory.

Age at national-team level: the 2026 World Cup, the oldest ever

The 2026 World Cup, in the United States, Mexico and Canada, was the oldest on record (average age of starting elevens above 28). Following the reading set out so far, even at the highest level of international football national-team coaches would appear to select the most talented players regardless of age.

There is, though, another point of interest. Spain won the title with a squad average age of 26.8 years⁷, making them the sixth-youngest of the 48 participating nations. This suggests a reading consistent with what has been observed so far: age alone does not appear to be a decisive factor in success. Rather than building a squad that is exclusively young or exclusively experienced, it seems plausible that the most competitive teams manage to strike a balance between high-level young players and others in their competitive prime.

Younger players may offer intensity, room for growth and qualities already usable at the highest level; more mature ones bring experience and skills refined over time. Combining the two could help in meeting the objectives set, or at least in competing at the top. There is also something here for those working on the pitch: if more experienced players retain an advantage in skill, then working early on the technical and tactical abilities of young players, while broadening those of older ones, could shorten timescales and produce better results.

It remains the case that these are statistical tendencies, not laws. Exceptions exist and probably depend on factors that escape statistical reasoning. After all, winning — or even simply competing for the goals set at the start of a season — is not a matter that can be reduced to numbers. Organisation, continuity, player availability, quality of training and the ability to turn individual talent into collective performance all help explain why teams of similar value achieve different results, and why in some cases less expensive squads manage to overcome financially stronger opponents. It is in that gap between value on paper and performance on the pitch that much of a coach’s work is played out.

Notes

1. Nevill, A. M., Smith, J. & Cloak, R. (2026). How have body size, age, and the use of substitutes evolved in English professional football between the 6 seasons 1973–4, 1983–4, 1993–4 to 2023–4? International Journal of Sports Science & Coaching. https://doi.org/10.1177/17479541261450306
2. BBC Sport (2026). Taller, faster, older: how footballers’ bodies have changed in 50 years.https://www.bbc.com/news/articles/cx23018r8lxo — The article reports FIFA tracking data on top speeds at the 2022 World Cup, comments by Jens Bangsbo (University of Copenhagen), and UEFA technical data from EURO 2024.
3. Wittkugel, J., Memmert, D. & Wunderlich, F. (2022). Substitutions in football – what coaches think and what coaches do. Journal of Sports Sciences, 40(15), 1668–1677. https://doi.org/10.1080/02640414.2022.2099177
4. Kalén, A., Rey, E., Sal de Rellán-Guerra, A. & Lago-Peñas, C. (2019). Are Soccer Players Older Now Than Before? Aging Trends and Market Value in the Last Three Decades of the UEFA Champions League. Frontiers in Psychology, 10:76. https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2019.00076/full
5. Gerhards, J. & Mutz, M. (2017). Who wins the championship? Market value and team composition as predictors of success in the top European football leagues. European Societies, 19(3), 223–242. https://doi.org/10.1080/14616696.2016.1268704 
6. Hopkins, O. (2026). Youth, Peak Age or Experience: Which Premier League Squads Have the Right Age Profile?Opta Analyst. https://theanalyst.com/articles/premier-league-squad-age-youth-or-experience-2025-26
7. Sky Sport (2026). Mondiali 2026, l’età media delle Nazionali: le più giovani e le più esperte [2026 World Cup: average squad age by nation] (8 June 2026). https://sport.sky.it/calcio/mondiali/nazionali-mondiali-2026-eta-media-classifica