That man called the club on a Tuesday afternoon. He was not a player agent, not a broker, not a lawyer. He was selling canned oxygen.

The call lasted twelve minutes. He said the air we breathe contains only 21 percent oxygen, that elite players need more, that a few breaths from a compressed can would raise performance. Dr Claire-Marie Roberts listened to all of it. Then she gave an answer I believe will be quoted for years: the atmosphere already has 21 percent oxygen, and a player standing on a pitch is not so short of oxygen that he needs a can strapped to his hip.

She told that story to The Guardian. I read it and felt a chill of recognition. Eighteen years earlier, in a training-ground corridor in East Asia, I listened to a man in a suit pitch an "electromagnetic blood circulation stimulator" to a club's coaching staff. He also spoke fast. He also had slides. And the coaching staff also nodded politely, said they would "look into it", and three weeks later I saw a box of the thing sitting in the fitness room.

That is why I sat down to write this. Not to tear down sports science. But to point out something more uncomfortable: most of what elite football buys, shows off and copies from one another does not come with evidence proportionate to the money and the trust it demands.

A market of unproven things

Roberts is not an outsider. She spent nine years in the Premier League, two years at Coventry City in a role that helped the club win the Championship title, and worked with Frank Lampard's coaching staff. She is now Director of Human Performance at the McLaren Formula 1 team. That is a CV any fitness director in Europe would look up to.

And it is precisely a person with that CV who has come out to say that very little scientific evidence supports the therapies being used everywhere. That is the starting point of a much larger story than a single interview.

Look at the academic politics of it. In sports medicine, for an intervention to count as evidence-based, it must go through randomised controlled trials, be replicated by independent research groups, and show measurable effects on specific indicators: recovery time, delayed onset muscle soreness, blood creatine kinase levels, peak muscle force, muscle glycogen resynthesis. None of those steps is cheap. None is fast. And none is as attractive as a LinkedIn post.

She says she receives up to fifty LinkedIn messages a week advertising devices, supplements or technologies. Fifty messages. Every week. A performance director at an elite club has to learn to say no to almost all of them, or to do the research to filter out the two or three worth reading. The rest is a constant marketing stream flowing into the inbox of people under pressure to find a "marginal gain" for their club.

That is the structural crux. Elite football does not lack money. It lacks a mechanism for spending money correctly. A technical director who buys the wrong centre-back will be questioned within a few games. But a fitness director who buys an ineffective cold chamber will almost never be questioned, because the poor results of the cold chamber are drowned out by an injury, a defeat, an individual moment. Nobody can audit the margin of error of belief.

Cryotherapy: when cold becomes a faith

The cryotherapy chamber is one of the most powerful symbols of modern football. A player steps into a sealed pod, the temperature drops to minus one hundred degrees Celsius or lower, he stays in for two or three minutes, steps out with flushed skin, and the club's media team captures the moment for social media.

Roberts asks a simple but hard question: most top clubs have cold chambers, but very few can explain exactly why it works, on which physiological mechanism, and for which group of players the benefit outweighs the cost. She says the evidence for its effectiveness is vague. Some recent studies even suggest that cooling too aggressively after training may reduce muscle adaptability, because the mild post-training inflammation is part of the process of building muscle, and cooling too fast may blunt that adaptive signal.

This is something fans often miss. In training, muscles are not just damaged in order to recover as they were. They are damaged in order to adapt better. If you suppress the inflammatory response too early and too strongly, you can make a player feel better the next day while taking away part of the signal the body needs to become stronger over the following weeks. The pleasant sensation after a minute in a cold chamber may reassure the mind, but it says nothing about whether you are becoming stronger.

I once saw a club install a cold chamber at a cost a club official only laughed about and said "don't ask for the number". The chamber was used mainly during pre-season, when competitive pressure peaks. And throughout the time I followed that club, the number of muscle injuries did not fall. That does not mean the cold chamber caused the injuries. But it also did not prevent them. It only prevented the feeling that the coaching staff had forgotten something.

Ice: an old ritual in new scientific clothing

Ice is not new. Athletes a century ago soaked their legs in cold water after matches. Modern footballers do the same. But there is a large difference between soaking in cold water as a historical habit and presenting it as a proven scientific intervention.

Roberts places it next to the cryotherapy chamber as two variants of the same belief system. She does not say they are entirely useless. She says the evidence is unclear, and in some cases they may backfire on adaptation. What is notable is how rarely people distinguish between "feeling better after soaking" and "recovering better in order to play again". The subjective sensation is so strong that it becomes evidence enough for players, and sometimes for team doctors.

And here is a paradox I have witnessed. A player had a sleep problem. He slept five hours a night. He ate carelessly. He took ice baths three times a week, took photos, posted them online, and was confident he was recovering seriously. That player most needed a conversation with a sleep specialist, not a fourth ice bath in a week.

Roberts herself puts sleep and nutrition at the top of the list of the most important recovery therapies. She says it plainly: no cold chamber can compensate for a bad diet. That is scientifically uncontroversial, yet it still shocks an industry whose recovery budgets are pouring into devices that can be filmed for social media.

Supplements: the slow-burning bomb of doping

This is the most serious part of Roberts' story, and I believe it deserves more careful handling than cryotherapy.

She says football has a billion-dollar supplement industry dripping into every dressing room in the world. Wealthy players desperately seek shortcuts. They constantly look for capsules, powders, liquids in pink packaging promoted as "weight management support", "recovery enhancement", "cellular electrolyte balance". Many use them without understanding their mechanism, their content, their production batch, and sometimes their origin.

Roberts takes a clear stance: supplementation should be based on the body's actual needs, not on a product's promise. A player deficient in a specific micronutrient, identified by blood test, has a reason to supplement it. A player with an adequate diet and no deficiency gains nothing from an extra capsule, while taking on extra risk.

That risk is not small. Doping has a principle anyone in the industry knows: strict liability. It means a player is responsible for everything in his body, whether he intended it or not. If a capsule was contaminated with a banned substance from a production batch, the player is still suspended. And here is what the public imagination usually misses: in a huge supplement industry with complex supply chains, cross-contamination risk is real, and the consequence for a player can be a ban that changes an entire career.

What Roberts does is place two numbers side by side: on one side, the billion-dollar revenue of the supplement industry; on the other, the number of players who genuinely need supplementation based on biological need. The gap between those two numbers is the market of belief.

Kinesiology tape: a beautiful symbol with thin evidence

If you have watched a football match in any major league in the past fifteen years, you have seen kinesiology tape. Strips of coloured tape running down thighs, across shoulders, curling around calves. Cristiano Ronaldo uses it. Gareth Bale uses it. David Beckham used it. And because those names use it, millions of young players have copied it.

Roberts says the evidence that kinesiology tape prevents injury or improves performance is very thin. I want to pause here, because this is where fans most often misunderstand.

Nobody says the tape is entirely useless in every situation. In certain specific contexts, taping may improve proprioception, may create a sense of psychological stability for the wearer, may play a part in functional rehabilitation after a certain injury. But the distance between "may be useful in some situations" and "must be used in all situations as a standard preventive measure" is enormous. And it is exactly that gap that marketing steps into.

I once stood in the recovery area of a club in Asia and counted the unused rolls of tape in a drawer. There were more than three hundred rolls, all colours, all sizes, each priced at a rate that, multiplied out, equals the food budget of an entire youth team for a month. The recovery officer there told me something I have never forgotten: "The players want it, so we have to have it."

The shock of numbers nobody tells

Let us line up the facts in Roberts' story and look at them the way a reporter looks at a data table.

Roberts spent nine years working in the Premier League. She says the gap between science and practice is widening. She says she receives up to fifty advertising messages a week. She says most top clubs have cold chambers but cannot explain why. She says the supplement industry is a billion-dollar business. She says football is the most easily manipulated sport of all those she has witnessed, partly because the price of failure is too high.

That is not a list of legal accusations. It is a list of environmental conditions. When hundreds of advertising messages a month flow into the inbox of people responsible for players' health, when big clubs use devices whose mechanism they cannot explain, when top stars post photos with a new recovery symbol, the market is set up to absorb belief far faster than it can absorb evidence.

And when someone like Roberts, with enough credibility and enough position to need nobody's favour, comes out and says this, she is not talking about one specific club. She is talking about an entire industry.

My position, and why I am writing this

The tears in Kazan were not there to be wiped; they settled so that I could decode them.

In 2026, in Kazan, I followed Renato Augusto in the Brazil shirt. He came on in the sixtieth minute of the quarter-final against Belgium, provided one assist, and could not save the match. After the final whistle he wept. Then he picked up a Russian boy of Brazilian descent who was crying in the stands. I stood there, ignoring the statistical notepad, and only recorded how he spoke: "Football is for children to dream, not for adults to suffer."

I tell that story to say that I did not come to this article from a cold place. I came from the understanding that a dressing room is a very fragile place. Players are not rational utility-maximising machines. They are human beings under pressure, afraid of injury, afraid of being substituted, afraid of losing a contract, needing to believe that something they are doing will make a difference.

And that is exactly why they are easy to manipulate.

Why belief in devices and white powder persists

What I want to make clear here is not that a few players are naive. It is that there is a systematic psychological mechanism.

Players at the elite level live in an extremely harsh environment. Every match is an evaluation of honour. Every training session is an injury risk. Every week is a chain of decisions in which almost no decision allows them to try again. In that environment, the natural psychology is to seek control. You cannot control the opponent, cannot control the referee, cannot control the weather. But you can control what you drink, what tape you wear, how many minutes you spend in the cold chamber.

And once that sense of control has formed, removing it is very hard. Not only because it may genuinely be helping. But also because removing it creates a frightening psychological void.

I call it the effect of ritualised belief. Sociologists have studied this phenomenon for decades: when people are in a highly uncertain environment, they tend to build rituals, and they defend those rituals more strongly than they defend empirical arguments. Rituals soothe anxiety. And elite football is one of the most uncertain environments humans have created.

That is why scientific data, however strong, struggles to change the behaviour of a player who believes the ice bath helps him play better. Change does not come from imposition. Change comes from making the player understand the mechanism himself.

The trap of copying big clubs

Roberts makes clear that elite clubs such as Manchester City, Chelsea, or the England national team using these methods creates a distorted belief that the methods must be right. This is where I believe her article deserves repeated reading.

In football there is a hierarchy not of finance but of credibility. Big clubs do not just have better players. They have better analytics departments, better medical departments, and a halo effect that makes everything they do look right. When Manchester City installs a new type of cold chamber, lower-tier clubs do not wait for evaluation research. They install the same chamber. They call it "a sports-science update".

The problem is that big clubs can afford to be wrong. They have the budget to try and discard. They have the staffing to test many methods in parallel. But a lower-tier club has no such margin. If they buy an ineffective system, they do not just lose money. They lose a slice of budget that should have gone to a nutritionist, an injury clinic, a good physiotherapist.

A stadium stands empty and keeps the drumbeat for all those who know how to be silent.

I wrote that line in 2026, when stadiums were closed because of COVID-19 and a group of Beijing Guoan fans organised a Zoom watch party with 127 participants. Among them was eighty-year-old Mrs Li, who always placed the team's number 5 shirt beside the screen. She told me: "I don't watch football; I see my youth in them." I mention that here because it reminds me that football, at its deepest level, is not a market. It is a community. And a community deserves to be led by what is right, not by what is fashionable.

Corners the interview does not cover

To be fair, Roberts offers her claims based on professional experience, and The Guardian article does not cite specific studies with transparent references. I have no right to turn an expert's opinion into a scientific conclusion. But I do have the right to read its implications carefully.

The first thing to say clearly: some cryotherapy studies may show benefits for specific outcomes. The field is more complex than the label "pseudoscience". Objecting to widespread use does not mean denying every effect. Roberts says the evidence is vague, not that there is no evidence at all. That is a distinction fans need to keep.

Second, there is a part of the problem left off the table: the suppliers' motives. Roberts compares flashy marketing to "illicit profiteering". That is a strong comparison, and I think it is structurally accurate. When a seller profits regardless of whether the result is true, they have no incentive to tell you their product is useful only in a small segment. They have an incentive to say it is useful for everyone.

Third, there is a risk on the other side: the story of clubs' gullibility could be exploited to attack legitimate recovery methods. I have seen a club cut its entire recovery budget as a way of proving "scientific sobriety", and the result was more injuries because there was not enough staff for basic care. Extremes on both sides do harm.

How clubs should spend on recovery

If I had to give a decision framework to a fitness director, I would start with three questions.

Does this intervention have evidence from randomised controlled trials in my own population, or only in a group of players at an entirely different match load? Evidence in strength athletes differs greatly from evidence in footballers playing two matches a week.

Does this intervention replace or supplement the fundamentals? If a player sleeps eight hours, eats well, hydrates, and then uses an additional recovery device, that device sits at the supplemental layer. But if that player is sleep-deprived and eating poorly, buying a device does not solve the problem. It only makes the problem more expensive.

What risk does this intervention create that has not been stated? With supplements, the risk is cross-contamination with banned substances. With temperature devices, the risk is the effect on adaptation. With tape, the risk is smaller but still there: taking time and attention away from better-evidenced interventions.

What I would do if I were a fitness director

I would not ban players from using ice. Banning small rituals in a high-pressure environment can do more harm than good. But I would separate two questions: what players believe, and what players need.

I would build a recovery system with sleep and nutrition as the foundation, with concrete sleep tracking data for each player. I would place supplemental interventions in a catalogue that states the mechanism, the evidence, and the use case. I would run regular talks so players understand why some things are used and some are not. And I would publish the criteria for evaluating new devices so the coaching staff knows that buying a system does not equal buying an advantage.

Finally, I would make sure every player understands one thing about supplements: if you do not test your blood and do not check the production batch, you are playing a game whose rules say you are responsible for everything in your body.

Seven years and an apology

Seven years is the distance my apology had to roll across a generation of players.

In 2026, when Kim Min-jae was still playing for Beijing Guoan, I wrote an article criticising him as "reckless, lacking tactical discipline". It was a bad piece. I did not see the tactical context he was placed in, did not see what he was learning, and I used the words of a harsh writer instead of a careful observer.

Three years later, at the 2026 World Cup in Qatar, Kim Min-jae played brilliantly in South Korea's 2-1 win over Portugal, with six clearances and four aerial duels won. I trembled watching that match. Not from emotion. Because I realised I had been wrong, and wrong publicly. I found him in the mixed zone and apologised in front of colleagues. He smiled: "You taught me to be strong; I remember that."

I tell that story because it relates directly to this article. If I, a reporter with forty-nine years of observation, could be that wrong about one specific player, how wrong can an entire industry be about a system of health interventions? We should not be ashamed of being wrong. We should be ashamed of continuing to do wrong only because others are doing it too.

What is most frightening is not the cold chambers

After rereading Roberts' interview several times, I realised what worries me most is not cryotherapy chambers or kinesiology tape. Those are loud, visible, easy to dissect.

What worries me most is the silence. The silence between what players believe and what players are actually tested for. The silence between what clubs claim and what clubs can prove. The silence between a billion-dollar industry and a player who does not know where the capsule he took yesterday was manufactured.

Roberts says football is the most easily manipulated sport she has witnessed, partly because the price of failure is high. I want to add the other half of that sentence: precisely because the price of failure is high, people will buy anything sold with a good enough promise.

A team does not change its rhythm through tactics

A team does not change its rhythm through tactics, but through the burdens it carries that nobody sees.

I wrote that line after following a club that changed its entire way of playing yet could not change its fate that season. I think it holds in many fields, including performance science. A club does not get better just because it has one more device. It gets better when the invisible burdens, poor sleep, low trust, missing knowledge, missing transparency, are removed.

And this is the point I want to leave as a progressive suggestion, not a summary.

What happens if this industry asks itself one question

I do not believe football will soon abandon its old recovery symbols. Humans need rituals, and football creates many. The cold chamber will remain. The ice will remain. The tape will remain. But there is one question I believe will gradually become a standard in the coming years, and the clubs that answer it first will gain a real advantage: can we prove that what we are doing makes a difference, or can we only prove that the big clubs are doing it too?

That is a question that costs no money to ask. But it demands something more expensive than money: the humility to admit that a cold chamber, a roll of tape, a capsule, may not be the thing holding your club up. Sleep, meals, and an environment where players can speak honestly about what they are using may be. And if one day a young player at a small club reads Roberts' story and asks his team doctor one simple question, "Why are we using this?", then this interview will have done what it needed to do.