C. Cheshier, Brandie, Bert H. Jacobson, Carlos A. Estrada, Masoud Moghaddam, and Carter J. Stewart. “Effects of a Respiratory Resistance Mask on Forced Expiratory Volume at 1s (FEV1), Forced Vital Capacity (FVC) and the Ratio of FEV1/FVC Lung Function Following High Intensity Training (HIT)”. International Journal of Physical Education, Fitness and Sports 11, no. 2 (May 4, 2022): 28–34. Accessed April 25, 2024. https://ijpefs.org/index.php/ijpefs/article/view/361.