Different dynamics of expired droplets and aerosols by particle size during interval training

Abstract

We aimed to determine droplet and aerosol concentrations during interval exercise using an aero bike. The participants were 39 healthy university students. Using Power Max V3, an anaerobic power test was performed in the first stage to determine the load used for middle power training. In the second stage, the determined load amount was used for 30 s each for two sets of full-power pedaling. A particle counter was used to measure the exhaled droplets and aerosol during the interval exercise.

The results showed an increase in particles with a diameter of 0.3 to < 0.5 μm and 0.5 to < 1.0 μm with the start of movement, and a tendency of the particle size to constantly increase during exercise. Particles with a diameter of 1.0 to < 2.0 and 2.0 to < 5.0 μm peaked under exercise load and decreased with exercise cessation. For particles with a diameter of 1.0 to < 2.0 μm and 2.0 to < 5.0 μm, there was a significant difference between the particle concentrations at the peak and exercise cessation.

During exercise, aerosols in the exhaled air showed different dynamics depending on the particle size. Infectionprevention measures during sport activities should therefore be designed according to the particle size of the aerosols or droplets that are emitted during different stages of exercising.