Droplet and aerosol generation during high intensity exercise

Characterization of the size, number, volume, dispersion and clearance of droplet/aerosol particles during high intensity exercise. The COVID-19 pandemic is ongoing and there is little data on the spread of droplets and aerosols during moderate to high intensity exercise. Data on aerosolisation in exercise may assist in guiding rational use of face masks and allowing appropriate distancing in participant’s gymnasium’s as communities look to re-open in the COVID-19 era. The data will also guide appropriate safety precautions to staff involved in cardiopulmonary exercise testing and exercise echocardiography, where currently no evidence exists on droplet and aerosol generation. Study participants will undergo a maximal cardiopulmonary exercise test and a spirometry test using a Vyntus CPX metabolic chart and a lode bicycle ergometer. The exercise intensity (workload) at which the participants will exercise for multiple 5minutes bouts for the measurements of droplets and aerosols will be determined from this test. The participants will exercise for 5minutes at the determined workload using the Vyntus CPX metabolic chart to determine minute ventilation, flow and volume. Baseline measurements of droplet/aerosol particles will occur in the clean exercise room before commencement of the experiment. This clean room is an operating room with high efficiency particulate air (HEPA) filtered air. Droplet and aerosol particles will be detected using an Aerodynamic Particle Sizer (APS) and a Mini Wide Range Aerosol Spectrometer (MiniWRAS) that will be operated by experts in droplet/aerosol detection and behaviour. Participants will be asked to exercise for 5minutes at high intensity with no mask, a standard surgical mask and a N95 mask. Repeat droplet/aerosol measurements will occur during each stage after clearance of droplets/aerosols and return to baseline. All investigators will wear N95 masks to minimise droplet/aerosol contamination from subjects other than participants. Detection of droplet/aerosols will occur from sampling sites at increasing distance from the participants, 30cm, 1.5m and 3m, frontal, lateral and posterior. These distances will be measured and marked by tape on the floor prior to testing. The cardiopulmonary exercise test (CPET) will be conducted by a research nurse and exercise physiologist. The 5minute exercise sessions for the different measurements in the operating room will be supervised by a team of investigators including an anesthetist, research nurse, exercise physiologist and research scientists who will operate the APS and MiniWRAS. The participants will be asked to come in over three separate visits. The first visit will include the CPET and the 5minute exercise test at the determined workload. This visit will take around 1hour 30minutes of their time. The measurements in the operating room will take place over two full days with 8 exercise sessions, each taking 5minutes, per participant on each day. A total of 16, 5 minute exercise sessions per participant over the 2 days. Each separate measurement mask/no mask at different distances will take 5 minutes. Sufficient time will be given in between sessions to allow for the droplet/aerosol count to return back to baseline.