Special Edition: COVID-19 and Recreational Tennis

Today I am pressing the pause button on the Rules of Tennis examination to discuss COVID-19 and recreational tennis. It should come as no surprise that my social circles are heavily populated with avid tennis players. I am aware that a lot of the tennis players in my life will find a way to play no matter what. Others are wondering what the implications of continued play are in the age of COVID-19 and how to do so in the safest way possible.

Measures to enforce social distancing is a highly dynamic situation and will likely continue to persist for a while. For anyone living in an area where shelter in place has been directed, I believe that takes tennis off the table unless you have a tennis court in your backyard. I urge everyone to comply with the directives of your local heath and government officials.

The Lawn Tennis Association (LTA) is maintaining a terrific page with COVID-19 advice for coaches. The LTA is the UK version of the USTA. I have cherry picked advice from that page which I think are particularly pertinent to players and facilities in my social circles. I would also observe that the USTA hasn’t published anything nearly this useful.

• Clubhouses, Gyms, and Social Spaces should be closed. This includes toilet facilities. This is a conundrum because restrooms have a lot of surfaces that are commonly infected, but at the same time this is where hand washing typically occurs. Everyone needs to wash their hands at home and carry that hand sanitizer.
• Players are advised to not change ends during play.
• No physical contact between players.
• Wash hands before and after playing.
• Wipe down courtside benches. (I have been carrying bleach wipes in my tennis bag for this purpose. I have also been avoiding the bench areas in general.)
• Wipe down racquets. Do not share racquets.
• Use new balls.
• Don’t touch the balls with your hands.
• If playing a match with players from different households, consider having assigned balls for each player who serves. This is because no one should touch a ball that another player has touched.

The last three bullet points speaks directly to the question of how long the virus is likely to remain on the surface of a porous object such as a tennis ball. I regret to report that it doesn’t appear that anyone has ever studied tennis balls directly for the Corona/SARs/MERs strains of viruses. However, I think it is reasonable to use studies of how long the virus lives on hospital gowns as a reasonable approximation.

While it depends on the inoculation density of the virus to the surface, scientific analysis results range from 5 minutes to 2 days. There is a difference between disposable gowns and cotton gowns, with the natural absorbency of cotton being on the lower end of the range. Those numbers are from the peer-reviewed medical journal articles referenced below.

In “How to Make a Tennis Ball” I wrote about the fabric used to cover tennis balls. Tennis balls are usually some combination of wool and synthetic materials. My guess is that tennis balls are closer to the composition of disposable hospital gowns because they are slightly moisture repellent. It is a distinction that I am not sure really matters.

The salient question is whether the virus can live on and be transferred via the cloth that covers a tennis ball. With a 5 minute to 2 day lifespan, the answer is certainly yes. This is why having a couple of balls for each player to serve with makes sense. The general recommendation should be to not touch the balls with your hands if at all possible.

I also want to highlight to everyone that the health reporter at Ars Technica is maintaining a comprehensive page on the COVID-19 virus. Health reporter is a little bit of an undersell, Beth Mole has a Ph.D. in microbiology. It is a terrific facts based resources conveniently organized by questions that people are likely to have. It is really good stuff and everybody should consider bookmarking the page.

I consider myself to be somewhat lucky, as I live in close proximity to 6 beautiful park tennis courts, I own a couple of ball machines, and I have a spouse that can carry out a reasonable rally. Unless my city locks the courts or my region goes on complete lock down, I have a place to play without risk of spreading contamination beyond my immediate household.

Tomorrow I will return to analysis of the rules of tennis. In the meantime be safe and smart out there kids.

1. “Coronavirus (COVID-19) – Advice for coaches,” Lawn Tennis Association, UK, Page last viewed 3/23/2020
2. “Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents“, G. Kampf, the Journal of Hospital Infection, Volume 104, Issue 3, pages 246-251, March 2020.
3. “Survival of Severe Acute Respiratory Syndrome Coronavirus,” Mary Y.Y. Lai, Clinical Infectious Diseases, Volume 41, Issue 7, October 2005.
4. “Don’t Panic: The comprehensive Ars Technica guide to the coronavirus,”Beth Mole, Ars Technica, page viewed 3/23/2020