The U.S. Anti-Doping Agency’s investigation of Alberto Salazar, the most prominent track coach in the world, backed by Nike, the most powerful company in track, took so long that many wondered publicly if it had died out with a closed-door whimper.

But Monday night, more than four years after the agency launched its investigation of medical misconduct and rules violations within Salazar’s prestigious Nike Oregon Project, an arbitration panel delivered perhaps the most resounding blow in track: It ruled that the renowned coach had violated anti-doping rules and will be banned from the sport for four years.

The news came as Salazar’s athletes are dominating running’s premier events. Two have set world records this year; others have already won gold at this week’s World Championships or are set to race Tuesday night or later in the week; still others will vie for the win in the Chicago Marathon in two weeks. Effective immediately, Salazar can no longer coach those athletes — or any pro runners — and cannot serve on their support teams at events.

Salazar can, though, appeal the decision to the Court of Arbitration for Sport. In a brief press release Monday night, he indicated his intention to do so, and pointed out that the arbitration panel said that he had not had bad intentions.

“I have always ensured the WADA code is strictly followed,” he wrote, referring to the World Anti-Doping Agency. “The Oregon Project has never and will never permit doping.”

USADA had actually notified Salazar of rule violations more that two years ago, but he appealed, which led to a lengthy arbitration process.

The sanction will reverberate throughout the running world, but particularly in the U.S. — Salazar himself won the New York City Marathon three straight times from 1980-82, and he started the Oregon Project with Nike’s backing in 2001 to return American distance running to prominence, which he indeed helped accomplish. Salazar also coached British runner Mo Farah as he became the first man to win both the 5K and 10K at successive Olympics (2012 and 2016) and later received a knighthood. (No allegations have been leveled against Farah.)

Salazar has long been one of the public faces of Nike, which in 2014 signed a 23-year sponsorship deal with U.S.A. Track and Field. There is a building on the Nike campus in Beaverton, Oregon, named after Salazar, and Nike funded his legal defense before the arbitration panel.

Salazar is arguably the most famous nonathlete ever to receive a doping sanction. The fact that the sanction comes in the absence of any positive drug tests marks it as a rarity, but one that places it alongside two of the most prominent anti-doping cases in history — BALCO, which supplied hard-to-detect performance-enhancing drugs to pro athletes, and the investigation of cyclist Lance Armstrong, both of which involved sanctions without positive tests.

The arbitration panel decided that Salazar had committed three anti-doping rule violations: He participated in the administration of a prohibited method; he attempted to tamper with the doping control process; and he “trafficked” in testosterone, a banned substance.

The prohibited method in question was an intravenous infusion of the legal supplement L-carnitine — a naturally occurring amino acid that helps convert fat into energy — but in an amount far in excess of the allowed limit of 50 milliliters per six hours. The tampering charge involved Salazar’s instruction to athletes not to disclose to doping control officers that they had received infusions. The testosterone trafficking charge was the result of an experiment Salazar helped conduct in a lab on the Nike campus in which he applied testosterone gel to his sons to see how much would trigger a positive test.

Since shortly after ProPublica and the BBC first reported on the testosterone experiment in 2015, Salazar has contended that the purpose was to understand whether competitors might sabotage his athletes by rubbing testosterone gel on them.

USADA began investigating the NOP following the ProPublica-BBC report, which also detailed allegations that the track coach had given his star athletes medications — sleeping pills, painkillers, and asthma and thyroid medications — that weren’t prescribed, or urged them to get prescriptions they did not need, to gain a competitive advantage.

In a 32-page open letter published shortly after the report, Salazar admitted to some of the allegations, like the testosterone experiment, and to hiding prescription drugs in a hollowed-out book and magazine so that they would not be scrutinized by customs officials when he sent them internationally to an athlete. But he strongly denied ill intentions and told the newspaper The Oregonian that before authorities would find he had committed an anti-doping violation, “They will find Jimmy Hoffa’s body first.”

The prescription drug allegations provoked intense discussion in the running community about the ethics of using such medications for performance enhancement, but those drugs are not covered by the WADA code and thus were irrelevant for the arbitration panel.

Regarding the testosterone experiment, the arbitration panel noted that it “was conducted at a well known training facility … with no actual justification and involving the administration of a controlled substance in potential violation of federal laws.” The panel also noted that Mark Parker, the CEO of Nike, was kept abreast of the experiment. “It will be interesting to determine the minimal amount of topical male hormone required to create a positive test,” Parker wrote in an email in response to one of the experiment updates. On Monday, a Nike spokesperson said that the company supports Salazar in his decision to appeal the ruling.

On Monday night, USADA CEO Travis Tygart told ProPublica that “all those who are in sport companies, or otherwise, need to double down on clean sport and not getting in the way of athletes’ health and safety.” Tygart said the Salazar case “should open the eyes of people in those positions. Are they going to double down on doing the right thing going forward, or keep their heads in the sand?”

Dr. Jeffrey Brown, a Houston endocrinologist who treated numerous athletes — at times while also being paid by Nike — was also banned for four years in a decision made by a separate arbitration panel. (Brown can also appeal to the Court of Arbitration for Sport, whose rulings are final.) Arbitrators concluded that he administered a banned supplement infusion, tampered with medical records related to infusions and was complicit in Salazar’s trafficking of testosterone when he prescribed the testosterone used in the experiment at the Nike lab. Brown did not immediately respond to a call for comment.

Both Salazar and Brown were first notified by USADA that they had violated anti-doping statutes and would be sanctioned in June 2017. Both men contested the charges and the case went to the American Arbitration Association. Two independent three-person panels then held closed-door hearings in 2018, eventually leading to the decisions rendered Monday. None of the athletes named in the investigation are facing charges.

Some of the whistleblowers who first spoke to ProPublica and the BBC testified at those hearings, including former NOP assistant coach Steve Magness and former NOP runner Kara Goucher. Salazar and Brown also testified.

Before the hearings, a report leaked by hackers provided a look at some of what USADA had uncovered. The USADA interim investigation report to the Texas Medical Board noted that six NOP athletes were “highly likely” to have received intravenous infusions of the supplement L-carnitine far in excess of what anti-doping rules allow, as part of what Salazar inaccurately described as a “clinical trial.”

As a supplement, L-carnitine is legal and commonly consumed in pill form. But anti-doping rules prohibit infusions greater than 50 milliliters in six hours. USADA argued that Salazar and Brown coordinated the banned infusions in an effort to load the supplement into athletes’ muscles much more rapidly than could be achieved with pills or a new experimental drink.

Magness first went public with allegations of rule-breaking at NOP in 2015 as part of the ProPublica-BBC report. A number of elite runners also shared their experiences of questionable medical practices; a few were willing to put their names to the accounts. Goucher, who under Salazar won a silver medal at the 2007 World Championships, recalled Salazar giving her a medication she had not been prescribed and encouraging her to use it for weight loss before a race; distance runner Lauren Fleshman recounted Salazar telling her to use asthma medication for performance enhancement in a manner contrary to that indicated by her doctor.

In an interview this year, Magness, currently a University of Houston track coach, told ProPublica and the BBC that he was the test subject for the first L-carnitine infusion in 2011, when he was a 27-year-old NOP assistant coach. He also shared this account with arbitrators. Following the infusion, Magness recalled a marked improvement on a test of his V02 max — a measure of the amount of oxygen an individual can consume during an intense effort. Salazar, he said, was excited by the results and decided to use the procedure on NOP athletes.

Salazar’s enthusiasm was captured in an email he sent to Lance Armstrong shortly after viewing Magness’ test results: “Lance, call me asap! We have tested it and it’s amazing. You are the only athlete I’m going to tell the actual numbers to other than [two-time Olympic medalist] Galen Rupp.”

At the time, Magness said, he believed that the infusion was allowed. He said that he began to have doubts after Salazar sent emails instructing athletes not to disclose that they had received an infusion. Eventually, Magness came to accept that he had participated in a banned procedure. “At the time, I had no idea,” he told ProPublica and the BBC. “It doesn’t excuse it. I take responsibility for what I did, but unlike the vast majority of people in this sport I did something about it.” Magness said he hopes that his example will lead more athletes and coaches to speak out about doping violations and unethical medical practices.

Some of the athletes who underwent infusions expressed reservations or asked questions at first. According to an interview with USADA given under oath, Olympian Dathan Ritzenhein asked Salazar: “Are you sure this is legal? This doesn’t sound legal.” Salazar later emailed Ritzenhein informing him that “everything is above board and cleared thru USADA,” a claim that USADA called “both ironic and inaccurate” in its interim report.

USADA’s interim report also noted that Brown seemed to have altered medical records provided as part of the investigation. Ritzenhein provided USADA with medical records directly, and also gave the agency permission to obtain his records from Brown. The records provided by Brown have added notation indicating that Ritzenhein’s infusion was just below the allowable limit.

When Magness saw that, he said he compared his own infusion records from Brown to those the doctor submitted to USADA, and he noticed discrepancies that he shared with ProPublica and the BBC. The arbitration panel ultimately agreed with USADA’s contention that Brown altered medical records “after being informed of the anti-doping investigation” and in an effort to manipulate evidence provided to the panel.

Brown is well known in elite running circles in the U.S. for his liberal prescribing of thyroid hormone. Thyroid hormone is not banned by anti-doping rules. But as evidence emerged that it was being prescribed for performance enhancement rather than medical necessity, some athletes deemed its use unethical, and officials from UK Anti-Doping and USADA — citing performance enhancement and health concerns — called for WADA to restrict thyroid hormone.

Some former NOP athletes and staff recounted to ProPublica and the BBC an inside joke within the elite running group: In addition to being fast, a runner had to get prescriptions for asthma or thyroid medication to be part of the team. (Salazar strongly disputed this characterization, and he said that most NOP athletes did not have prescriptions for asthma or thyroid drugs.)

Brown, for his part, had long said openly that his treatment was medically sensible, even though mainstream medical literature would suggest that athletes he treated already had normal thyroid function.

In 2013, The Wall Street Journal published a profile of Brown titled, “U.S. Track’s Unconventional Physician,” in which Brown identified himself as a consultant to U.S.A. Track and Field and the U.S. Olympic Committee, and a doctor whose patients had won 15 gold medals. The story said that both organizations had referred athletes to Brown, but both denied that he was a consultant. According to emails viewed by ProPublica, later that year during the World Championships, Brown was corresponding regularly with USOC staff members to coordinate athletes’ medical regimen.

On Tuesday, the weight of Salazar’s ban was felt immediately. The International Association of Athletics Federations deactivated his World Championships accreditation, barring him from athletes’ and coaches’ areas of the stadium in Doha, Qatar, or from having any access to his athletes. Two are in the men’s 800-meters final Tuesday night.