People exercising in gyms can push out more than 100 times more spit particles than someone at rest - making crowded exercise facilities a potential hot-spot for Covid-19 spread.
RNZ's 'whose backwash are you breathing' project has revealed high levels of carbon dioxide in gyms and yoga studios, indicating ventilation is poor.
Here's Farah Hancock with why you might want to ask your gym to keep the windows open.
