IRVING, Texas – Age is just a number, or so they say. It is a saying that is meant as motivation, an exhortation not to curl up and prepare for death the moment you hit 60, an encouragement to be fit and healthy and to continue living the best life you can.

In that context, it’s a fine aphorism. As a comment on the biology of aging, it could not be more wrong.

Age is more than a number. It is a physical reality. Plenty of active 60-year-olds are unquestionably fitter than plenty of corpulent, sedentary 30-year-olds; but no matter how fit they are, it’s a given that their physiology is different from when they themselves were 30. As we age, our eyesight tends to diminish, as does our hearing; our skin becomes less elastic and so too, often, do things like the bladder - hence the middle-of-the night bathroom visits. Reflexes slow, as signals take longer to travel along our nerves. Muscles become weaker. Brains shrink.

Such changes are not solely the province of the truly old, either. Our , and recent studies , at around age 44 and age 60. And while genetics influence much of how and how fast we age, so do our lifestyles. Someone who has eaten well, exercised regularly, and largely avoided alcohol and drugs is more likely to fare better than someone who, to pick a purely hypothetical example, was frequently strung out on any number of substances and whose professional career involved being punched in the head and suffering multiple micro-concussions.

Which of course brings us to Mike Tyson.

Mike Tyson is 58 years old. He was once a ferociously effective boxer. He won the heavyweight championship of the world in 1986, when Ronald Reagan was president and the Soviet Union was still a thing. He lost it in 1990, his life already threatening to come off the rails. He was burning out and already past his boxing peak at this point. He was 24. By the time he was 30, he was a convicted rapist who had completed a stint in jail. Between 1997 and 2005, he bit off a piece of Evander Holyfield’s ear and chewed on the thigh of Lennox Lewis, who promptly battered him into defeat. He tried to break Frans Botha’s arm and bite off Kevin McBride’s nipple. 

And now, at 58, after nearly 20 years out of the ring (except for an eight-round exhibition against the similarly aged Roy Jones, Jr.) he is about to take on a 27-year-old opponent in Jake Paul.

We have already seen this show before. Three years ago, Holyfield - at that time also 58 – took on MMA veteran and novice boxer Vitor Belfort, who was then 44. In the space of 109 seconds, Holyfield slipped and fell, was knocked to the canvas and was stopped.

Granted, Holyfield did not have the advantage of a lengthy training camp; he stepped in at the metaphorical last minute to replace a COVID-stricken Oscar De La Hoya. In contrast, Tyson has seemingly been training rigorously for some months for this opportunity. But Belfort was just 14 years Holyfield’s junior; Paul is younger than Tyson by fully 31 years and, at 27, should be in his physical prime.

BoxingScene asked the Texas Department of Licensing and Regulation whether Tyson would be subject to any additional tests and scans to determine his fitness for the contest; in response, TDLR communications manager Tela Mange emailed that, “In consultation with members of our advisory board who are physicians, TDLR has long had in place rules regarding additional testing of fighters over the age of 36. Any contestant over the age of 36 must submit favorable results of an EEG and an EKG test before they will be allowed to compete in a combative sports competition in Texas.” 

Asked whether ringside officials will be paying extra attention to Tyson’s welfare in the ring on Friday, she added that, “The safety of the contestants competing in the ring or the cage is always the primary concern of TDLR staff and ringside physicians. This competition is no different.” (The two-minute round and 14-ounce glove stipulations that will be in force were, she explained, a holdover from when the bout was originally planned as an exhibition. “The promoter first proposed the bout as an exhibition, and we indicated that we would require two-minute rounds and 14-ounce gloves. Once the promoter asked to have a fully sanctioned, professional bout, they asked whether TDLR rules would allow for a professional bout to keep those same gloving and round requirements,” she wrote.)

Earlier this year, before Tyson-Paul was announced, neurologist Dr. Nitin Sethi of New York-Presbyterian Hospital Weill Cornell Medical Center entitled “How old is too old to fight in boxing? Age is not just a number,” in which he noted that, “Over the years, robust research has linked concussions, moderate to severe traumatic brain injury to an increased risk of developing neurodegenerative diseases such as TES and Alzheimer’s disease. The consequences of concussions are not just short-term such as headache but also include structural degenerative changes in the temporal and frontal lobes.”

In a conversation with BoxingScene, Dr. Sethi was keen to stress that he did not want to offer any comment on the specifics of Tyson’s case, noting that he has not examined him in any way and that the effects of aging can vary considerably among individuals. "Some of my patients age very gracefully,” he pointed out. “They're 80 years old, and they'll come in and I’ll ask them, ‘Can you sit on my examination table?’ and they’ll jump on it. And people who are 20 years younger, and they're coming in a wheelchair.”

That said, there are certain undeniable factors that accompany aging in athletes and all the more so in boxing. Usain Bolt can’t still run the 100 meters in 9.58 seconds; in his last major championship, he had to settle for bronze and, at age 38, he might not even make an Olympic final anymore. 

But the only risk Bolt would face from trying to do so is the embarrassment of falling short. Professional prizefighters get hit in the head; slower, less capable ones get hit in the head more often and more heavily.

“I'm very passionate about protecting fighters’ brain health,” Sethi, who is a self-professed boxing fan, told BoxingScene. “And boxing is a very unique sport, in that every punch which is thrown at the opponent's head is thrown with the intention of winning by causing a knockout, which is a concussive injury of the brain. What I personally believe is that as you get older, it takes a longer time to recover from a concussive head injury as compared to when you are younger. And then I think one big thing in boxing, which I feel many people ignore, is that while we all talk about the acute neurological injuries in boxing like concussions – or, heaven forbid, a traumatic subdural hematoma -  what we forget is that it's like a pyramid. The vast number of neurological injuries are chronic and hidden. It's like an iceberg. And boxers past the age of 35 or 40, after they have retired, they may have chronic headaches, chronic disease, chronic post concussive symptoms, changes in mood and behaviors. So, that's why I think age becomes a big factor, because punches do add up.”

Sethi is reluctant to suggest that there be a mandatory retirement age for boxers, not least as he notes that more defensively-minded boxers who live a healthy lifestyle – Floyd Mayweather or Bernard Hopkins, for example – appear able to continue at a higher level for longer. 

“If somebody were to say to me in 15 years, ‘Dr Sethi, now that you have turned 65 you should not practice neurology anymore. You're probably not as good as you were when you were in your 50s,’ I would take it pretty hard,” he said. “You know, these are professional boxers. That's how they make their careers. So, personally, I feel a blanket, one size fits all, statement probably is not the way to go about it.”

He instead proposes that boxers over the age of 40 should be subject to multiple batteries of cardiovascular and cognitive tests to examine thoroughly whether they should be permitted to fight, including examination of video of the boxer in training; electrocardiograms and echocardiograms to determine cardiovascular health; MRIs of the brain and magnetic resonance angiographies (MRAs) of the head to rule out vascular malformations such as aneurysms and arteriovenous malformations; and, if requested by a neurologist, a formal neurocognitive evaluation to detect latent neurodegenerative disorders. 

Even such tests won’t catch all the damage a brain has accumulated; diagnosis of CTE can presently only be confirmed post-mortem, for example. Nor can they remove the risk of damage or disaster: the nature of boxing is such that nothing can make it truly safe. But, Sethi argues, “given that the sport has very high risk of acute, traumatic brain injury and chronic neural injuries, we have to do everything we can to try to make the sport safer.”

And one way to do that is to make older boxers jump through hoops to prove their suitability to fight.

“Boxing remains a niche sport,” he said. “A lot of people who don't follow boxing, they don't like boxing. They may say: ‘This is crazy. I don't know why you follow this sport.’ So when people look at us like that, we need to be able to show we’re all trying to do the right thing, at least.  That's why I say in my article that it requires a collective effort to try to make the sport safer. And age does become a factor. There's no denial of the fact that as you age, you slow down.”

Kieran Mulvaney has written, broadcast and podcasted about boxing for HBO, Showtime, ESPN and Reuters, among other outlets. He also writes regularly for National Geographic, has written several books on the Arctic and Antarctic, and is at his happiest hanging out with wild polar bears. His website is www.kieranmulvaney.com.