LAUSR

Significance Intensive endurance exercise can increase aerosol particle emission by over 100-fold, and there is evidence that SARS-CoV-2 has spread during indoor group exercise. However, data on aerosol particle emission during resistance exercise (i.e., weightlifting) and for “real-life” endurance or resistance training sessions are limited. To fill this knowledge gap, we measured aerosol particle emission during resistance exercise and real-life exercise sessions. We observed that aerosol particle emission increased 10-fold during resistance exercise. Furthermore, we calculated that the infection risk for a real-life spinning class (i.e., cycle ergometer exercise) is sixfold higher than for a resistance exercise session. Thus, during waves of aerosol-mediated infections with severe consequences, exercisers should mainly do resistance training and do especially high intensity endurance training outdoors.