As a team physician for Tulane and co-director of the New Orleans school's Center for Sport, Dr. Gregory Stewart is never far from the ravages of the coronavirus. Louisiana has one of the nation's highest COVID-19 per-capita death rates, with over 4,100 total reported as of Sunday. All 64 parishes are considered hot spots for the virus.
The state also has one of the nation's highest obesity rates. Experts say the two are related. Stewart doesn't doubt it. He's heard from enough doctors in coronavirus wards to be convinced.
"They tell you that they walk through and everyone was obese," Stewart said in a telephone interview. "They would walk through and they would look at it and they'd be like, 'Oh, my gosh.' "
One month from the start of its regular season, the NFL is grappling with a set of coronavirus questions unique to the sports landscape. It's not just a matter of how 32 teams can stay healthy amid a pandemic without a "bubble" environment. It's what could become of a group of players that health officials consider at risk for severe infection.
According to the Centers for Disease Control and Prevention, people with a body mass index of 30 or higher are considered obese and more likely to become seriously ill because of COVID-19, the disease caused by the novel coronavirus. Under that definition, every Ravens lineman would be considered at risk. At a listed weight of 285 pounds, defensive end Derek Wolfe has a BMI of 33.8 -- and he's the lightest lineman on the team.
But while the team's biggest cohort will play almost every snap in a Petri dish of sweat, saliva and whatever else gets swapped at the line of scrimmage, there is growing evidence that the NFL's heavyweights might not be an especially vulnerable population.
Stewart, who has studied heart abnormalities in former NFL players and chairs the American Athletic Conference's COVID-19 Medical Advisory Group, called the disease "very much a disease of sedentary people." High blood pressure, obesity and diabetes are among the most common comorbidities found in coronavirus patients.
"Well, that's your couch potato," Stewart said. "That's your person who never goes out and exercises, and overeats and underexercises. So is exercise somehow protective for the bad effects of COVID-19? Well, obviously, there's a lot of people that have caught it and died and had bad outcomes when you go and look at the news, and here's your triathlete who got it and had significant problems, or your marathoner. But I think that that's more the exception than the rule."
In a letter to player agents that addressed risk factors for the virus, the NFL Players Association noted that a BMI of over 30 was considered an underlying condition, echoing CDC guidelines. But BMI, which is derived from a simple formula (weight divided by height squared), does not account for the relative proportions of bone, muscle and fat in the body.
Dr. David Kass, a cardiologist who leads the Institute of CardioScience within the Johns Hopkins University School of Medicine, said BMI "warps weight." When he lectures on heart failure, he shows his audience pictures of two types of beef. The first is a lean strip steak; the second is a Kobe steak. They're the same size, Kass explains, but the fat content in Kobe beef is much higher.