Vape Aerosol Exposure Decreases Voluntary Exercise in Mice
Electronic cigarette use (vaping) is generally accepted as a less harmful alternative to traditional cigarette smoking. However, so called "never smokers" including young adults and teenagers are often recruited through targeted advertising and appealing vape juice flavors. Any fitness cost of vaping matters for young people who exercise or play sports. We therefore tracked running distance in a mouse model of voluntary exercise to assess the effect of vaping. Specifically, we asked whether vaping decreases exercise performance, and whether there is progressive change over time. Experimental groups of mice subjected to whole-body inhalation exposure and corresponding non-exposed controls were housed in cages with running wheels. Daily wheel laps were recorded over the 8-week exposure period and analyzed using hierarchical generalized additive mixed models. Vape-exposed females ran 32% fewer laps than control females. Vape-exposed males showed a smaller reduction of 15% that did not reach statistical significance. The reduction was 10,025 laps per day larger in females than in males (p = 0.02). In females, the difference was present from the first weeks of exposure and was larger by the end of the study. The results demonstrate that vape exposure is associated with reduced voluntary aerobic activity. The analysis illustrates how nonlinear longitudinal modeling clarifies both the size and the temporal character of treatment effect in this experimental model. These findings reveal that nicotine-free components of vape aerosol reduce voluntary aerobic activity, highlighting an overlooked facet of vaping toxicity research which is particularly relevant for young and physically active users.