significant cardiorespiratory function in the low-grade volleyball physical activity
versus mid-grade volleyball physical activity groups, the longer the volleyball exercise
time, the greater the index values (i.e., 2.72 L > 2.52 L, 1.77 L > 1.73 L, 80.1% >
78.91%, 2.53 L > 2.5 L). For cardiorespiratory fitness that was significant in the high-
grade volleyball physical activity and very high-grade volleyball physical activity
groups, the longer the duration of volleyball exercise, the smaller the index values
(i.e., 1.98 L < 2.04 L, 1.04 L < 1.13 L, 60.78% < 63.63%, 1.83 L < 1.99 L). The reason
for the results of this study may be that the benefits of volleyball exercise on human
cardiorespiratory function outweigh the negative effects of heavy haze when the
physical activity has not yet reached the level of high-grade volleyball physical activity.
At this point, the higher the level of volleyball physical activity, the better the state of
cardiorespiratory function. Volleyball brought greater physical benefits to the target
group by lowering blood pressure and improving pulmonary ventilation and maximum
oxygen uptake in the study subjects. It also completely suppressed the negative
physical effects of fine and respirable particulate matter in a heavy haze environment.
causing the target subject's expiratory lung volume with force, expiratory volume with
force in 1 second, expiratory volume to lung volume ratio, and maximum expiratory
flow rate to increase from 2.52 L, 1.73 L, 78.91%, and 2.5 L to 2.72 L, 1.77 L, 80.1%,
and 2.53 L, respectively. but when physical activity reaches high levels of volleyball
physical activity and above, not only is the respiratory rate typically faster, but also the
probability is that breathing will be done through the mouth. This bypasses the
filtration effect of the nasal cavity, leading to more pollutant inhalation, irritating the
respiratory system, triggering inflammation, or obstructing the airway. At this point, the
positive effects of volleyball on human cardiorespiratory function, such as lowering
blood pressure, are far less than the risk of greater exposure of the human body to
large amounts of particulate matter that accumulate at low altitudes and do not diffuse
easily during breathing at faster respiratory rates. This results in the body's
cardiorespiratory function being far more susceptible to the pollution conditions of a
heavy haze environment than at low levels of volleyball physical activity versus
medium levels of volleyball physical activity. This resulted in a significant decrease in
the target subjects' forceful expiratory lung capacity, 1-second forceful expiratory
volume, expiratory volume to lung capacity ratio, and maximum expiratory flow rate
due to obstructive ventilation dysfunction, obstructive emphysema, respiratory
ventilation dysfunction, restrictive ventilation dysfunction, or mixed ventilation
dysfunction caused by heavy haze, from 2.04 L, 1.13 L, 63.63%, and 1.99 L,
respectively decreased to 1.98 L, 1.04 L, 60.78%, and 1.83 L. In conclusion,
excessive physical activity of volleyball in a heavy haze environment can aggravate
the inhalation of respirable particulate matter, resulting in the negative effects of a
heavy haze environment for the body, overriding the benefits of volleyball for the body.
5. DISCUSSION
For volleyball to achieve its essential role, the hazy environment needs to be
effectively improved, but the improvement process takes time to achieve. During this
https://doi.org/10.17993/3ctic.2023.122.360-377
3C TIC. Cuadernos de desarrollo aplicados a las TIC. ISSN: 2254-6529
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