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Background The coronavirus disease-19 (COVID-19) pandemic led to the prohibition of group-based exercise and the cancellation of sporting events. Evaluation of respiratory aerosol emissions is necessary to quantify exercise-related transmission risk and inform mitigation strategies. Methods Aerosol mass emission rates are calculated from concurrent aerosol and ventilation data, enabling absolute comparison. An aerodynamic particle sizer (0.54–20 μm diameter) samples exhalate from within a cardiopulmonary exercise testing mask, at rest, while speaking and during cycle ergometer-based exercise. Exercise challenge testing is performed to replicate typical gym-based exercise and very vigorous exercise, as determined by a preceding maximally exhaustive exercise test. Results We present data from 25 healthy participants (13 males, 12 females; 36.4 years). The size of aerosol particles generated at rest and during exercise is similar (unimodal ~0.57–0.71 µm), whereas vocalization also generated aerosol particles of larger size (i.e. was bimodal ~0.69 and ~1.74 µm). The aerosol mass emission rate during speaking (0.092 ng s−1; minute ventilation (VE) 15.1 L min−1) and vigorous exercise (0.207 ng s−1, p = 0.726; VE 62.6 L min−1) is similar, but lower than during very vigorous exercise (0.682 ng s−1, p < 0.001; VE 113.6 L min−1). Conclusions Vocalisation drives greater aerosol mass emission rates, compared to breathing at rest. Aerosol mass emission rates in exercise rise with intensity. Aerosol mass emission rates during vigorous exercise are no different from speaking at a conversational level. Mitigation strategies for airborne pathogens for non-exercise-based social interactions incorporating vocalisation, may be suitable for the majority of exercise settings. However, the use of facemasks when exercising may be less effective, given the smaller size of particles produced.

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&lt;p&gt;The importance of bio-aerosols across the earth system has been known for some time. With the unfortunate situation arising from the COVID19 pandemic, attention has turned to appropriate detection technologies that could be used to better understand the contribution of aerosols generated from the lung in various settings. In this project, the wideband Integrated Bioaerosol Sensor (WIBS-NEO) was deployed in a zero-background clinical environment which permitted the aerosols measured to be directly ascribed to specific vocalisations undertaken. The fluorescent signatures of expelled aerosol from a variety of human participants were captured during individual speech and language therapy activities (speaking, humming, sustained phonation, fricatives, projection, and tongue trills). In this presentation we present the varying fluorescent signatures and particle morphologies.&lt;/p&gt;&lt;p&gt;Furthermore, millions across the UK have now adopted face coverings into their day to day lives with one of the most widely adopted and commonplace being the disposable surgical face mask. Yet, questions still remain as to what types of vocalisations produce the most aerosols and the efficacy of the face mask in reducing transmission. To supplement this, measurements with the WIBS-NEO were conducted where participants did not wear a mask, and then subsequently repeated wearing a surgical mask. The fluorescent intensity, concentration (cm&lt;sup&gt;3&lt;/sup&gt;), size (um), and asphericity were then compared for each activity with and without a mask.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;WIBS-NEO information:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;https://www.dropletmeasurement.com/product/wideband-integrated-bioaerosol-sensor/&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Example paper using the WIBS:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;E.Toprak and M. Schnaiter, &lt;em&gt;Atmos. Chem. Phys.&lt;/em&gt;, 2013, &lt;strong&gt;13&lt;/strong&gt;, 225&amp;#8211;243.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

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