Football players ram into each other to begin a play and usually end it with a collision that brings a ball carrier to the ground.
Hockey players pin each other against the boards with body checks and use any physical means necessary to separate an opponent from the puck.
Wrestlers square off inches apart, then almost immediately grab arms, bump heads and exert themselves in face-to-face contact, often breathing the same air for six minutes or more.
Throughout the COVID-19 pandemic, public health officials have stressed social distancing to combat the deadly virus, which is largely spread through infected droplets from coughing, sneezing and talking. But for contact sports, social distancing isn't a workable option.
As football, hockey and wrestling move ahead toward restarting, those involved are working to keep coronavirus cases to a minimum, hoping to avoid a pause in play or another shutdown. And the margins are razor-thin for these sports, given how close the competitors are when they square off.
"With it being an airborne illness, there's effort and exertion, and spit and droplets will be projected through that," said Troy Hoehn, a supervisor athletic trainer for the Mayo Clinic Health System and past president of the Minnesota Athletic Trainers' Association. "That's where the difficulty comes in those sports where you've got people that are really close together for an extended period of time."
Last week, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, cast doubt on football returning in 2020 without having all teams report to one solitary location.
"Unless players are essentially in a bubble — insulated from the community and they are tested every day — it would be very hard to see how football is able to be played this fall," Fauci told CNN. "If there is a second wave, which is certainly a possibility and which could be complicated by the predictable flu season, football may not happen this year."