RIO DE JANEIRO -- There may have been a time, when athletes smoked pipes, competed in everyday clothes and didn't tweet sponsored messages, a time that fewer and fewer people can remember, when sports were "real," not theatre.

Theater requires audiences to suspend their disbelief, to pretend that the cardboard tree on stage is a forest and that the actor holding a skull is Hamlet.

Today, after decades of doping, the best performances in the world of sport are almost immediately followed by whispers and social media postings with one question: "What are they on?" That wasn't always the case. Sports used to be seen as the most real form of entertainment, with regular humans doing amazing things.

Paavo Nurmi, the first athlete to win five gold medals at a single Olympics, in Paris in 1924, was a former baker's errands boy who used his earnings from running to provide his family with electric light and running water.

Bill Foulkes, who played in 688 matches for Manchester United from 1952 to 1970, kept his job in a coal mine when starting out at Old Trafford, underground five days a week and training with the club on Tuesday and Thursday evenings.

Ethiopia's Abebe Bikila retained his Olympic marathon title in 1964 just 40 days after having his appendix removed. Swedish skiing great Ingemar Stenmark strapped on his first skis at age five.

Their achievements, one assumes with the rose-colored glasses of nostalgia, didn't need to be second-guessed at every turn. The "Say it ain't so, Joe" reaction in more innocent times to suspect performances has become a jaded shoulder shrug of "Dude, what did you expect?" or its 140-character equivalent.

The acidic drip, drip, drip of cheating by greedy individuals and insecure governments in the past half-century caused this corrosion of the Olympic experience. Lance Armstrong, Marion Jones, abused East German teenagers, urine-swapping Russian agents, they all brought doubt to sports. The paradise of being able to accept sporting excellence for what it is, simply excellent, has been lost.

Not completely. But enough that arched eyebrows have become as necessary as a cold drink and a comfy cushion when watching cycling, track and field, and other sports taken for too many rides by dopers. Olympic weightlifting isn't worth watching at all, given how history suggests that a sizeable proportion of medallists in Rio de Janeiro will likely be handing them back when the International Olympic Committee gets around to thawing out and retesting drug-test samples taken at these games, as it has done with those from Beijing in 2008 and London in 2012. Those retests have so far yielded 98 positives from multiple countries and sports, including 12 weightlifting medallists from 2012.

So, of course, Wayde van Niekerk had to be asked whether he is on drugs after he broke Michael Johnson's 17-year-old world record in the Rio Games' 400-meter final. Hopefully, Van Niekerk didn't take the questions personally. They are just symptoms of the twice-bitten times; boxes self-respecting journalists must tick. The South African replied that he is clean.

Armstrong, of course, used to say the same thing, evading most journalists' sniff tests even more expertly than he and his teammates used to limbo under doping controls. Even now, after Armstrong's belated confessions that his Tour de France wins were a sham, the ease with which he lied remains remarkable for its assured delivery.

"I've never taken performance-enhancing drugs," he said in a sworn deposition in 2005. "How many times do I have say it?"

Re-watching that, thinking how much of sports' credibility he and other dopers have stolen, it is impossible not to feel cynical and angry. Likewise, watching any Russian athlete in Rio has been a struggle. Hard not to picture urine samples being passed at night through a hole in the wall of the drug-test lab at the 2014 Sochi Olympics for tipping down a drain.

Still, it is important to have some faith.

The reason to believe most of what you are seeing from Rio is not the 5,500 drug tests, which smart dopers know how to trick, or what athletes say, but because the alternative -- not believing -- is simply too depressing. Not trusting that most Olympians got here through hard work, good genes and honesty would mean that hard work, good genes, honesty count for nothing. And that is not true.

Not believing in Van Niekerk's time of 43.03 seconds simply because no one has run that fast before would mean also not believing that 43.03 seconds is humanly possible at all. Same goes for Michael Phelps' unprecedented 28 swimming medals or Usain Bolt's now seven (and counting) Olympic sprinting golds. Doubting brilliance simply because it is brilliant undermines the strongest reason for holding the games: so that humanity's fastest, springiest and strongest can get together to expand the envelope of what is physically and mentally possible.

So although that voice in your head asking "Is this for real?" is understandable, even healthy, don't be drowned out by it.

Dial down the cynicism, arch just one eyebrow, and try to enjoy the theatre.