Comparison of Pulmonary Measures During Virtual Reality Exercise and Outdoor Exercise

The development of high-tech wearable devices is revolutionizing not only the way we live but also the way we exercise. Pulmonary responses to virtual reality (VR), as one of the latest technologies on the market, have been largely unstudied. To ensure that the workload is equivalent, one approach is to compare VR and outdoor (OUT) walks of similar visual environments. The findings from this study may be an initial step in providing evidence of VR as a platform for virtual exercise. PURPOSE: The purpose of this study was to assess whether walking in VR affects pulmonary responses differently than outdoor walking. METHODS: Fifteen participants completed the study (n=8 female, n=7 male; age: 26±10yrs; height: 171±9cm; mass: 74±11kg). Participants were equipped with a COSMED K5 metabolic system attached through a harness and a VR headset (HTC VIVE Pro Eye; during the VR walk). The order of walking in VR and outdoor settings was counterbalanced to minimize order effects. The VR walk was a self-paced ~9-minute walk completed on a VR treadmill (KAT VR, KAT Walk C2+) while viewing a 360° video of an outdoor path in a VR headset (HTC VIVE Pro Eye). The outdoor walk was a self-paced half mile walk on the path shown in the video. Dependent variables included ventilation (VE [L/min]), tidal volume (VT [L]), and respiratory frequency (Rf [breaths per min]). Data were analyzed using paired t-tests with significance accepted at p<0.05. Effect size measurements were determined by interpretation of small (d=0.2), medium (d=0.5), and large (d=0.8). RESULTS: Significant differences were observed for Rf (VR=31±4; OUT=27±6 L/min, p=0.01, d=0.00 [small]). However, there were no differences observed for VT (VR=1.2±0.2 vs. OUT=1.4±0.4 L, p=0.10, d=0.004 [small]) and VE (VR=36±7 vs. OUT=34±8 L/min, p=0.36, d=0.00 [small]). CONCLUSION: The results of this study provide evidence that walking indoors on a VR treadmill affects pulmonary responses differently than walking outdoors. From a pulmonary perspective, walking on a VR treadmill seems to increase the number of breaths taken, while tending to decrease the depth of breath. Future studies should be designed to determine the underlying mechanisms behind this phenomenon, considering such factors as experience walking on a VR treadmill, the type of VR experience, and pacing during the VR walk.