Our study showed many inconclusive results. As a whole, the mask group did not perform better or worse than the control group, and there were not any findings found to be statistically significant (p<.05). However, it should be noted that neither the control group nor the mask group saw improvements from pre-test to post-test. The participants would workout consistently four times a week for 45-60 minutes per session. This was done throughout the five-week period, but the results from the study showed no statistically significant improvement in VO2 max, FEV, MVV, or body composition measures for either group. This could be simply that the workouts the participants were performing at the CrossFit gym were not intense enough to cause improvements in these parameters.

There are also other potential limitations as to why no improvements were seen from our study. One of the limitations to the present study is the population size. The use of a larger population size would improve both the validity and reliability of the results. Furthermore, the present study compared pre- and post-tests that were five weeks apart. The short nature of this study may have caused the results to be inconclusive due to the lack of time for physiological adaptations caused by the training masks. Finally, a placebo effect may have influenced the results as well. Physiological adaptations in participants may have occurred based on the participants’ beliefs about the group they were in. For example, participants in the experimental group may have exercised harder or not as hard due to the perceived effects of the training mask.

These limitations should be addressed in future studies on the effects of elevation training masks on certain physiological factors. Throughout the testing protocol there were various complications that created confounds in the data. The metabolic cart was unable to handle the workload required of continuous Bruce Protocol GXT testing. Because of this we had to switch from using the Bruce Protocol to the Arizona Protocol. After this change was made the metabolic cart performed as expected.

A sample size of 20 was obtained with only 18 seeing the study to completion. For future studies in this field of study we would recommend having a larger sample size which would allow for greater dispersion of results and identifying any other effects of the masks. Although the participants completed the same workouts, having a regiment that is more consistently geared towards cardiovascular endurance might produce a greater comparison between groups. Tracking the progress of the participants over three GXT’s, a pre-, mid-, and post-test, would show any other potential changes over the testing period. We would also recommend increasing the duration of the study from five to twelve weeks to have more data to draw from and allow for greater physiological change to occur.

Another way to improve the study would be to make sure that the two testing groups (control, and experimental) are unaware of each other. This would help to avoid the John Henry Effect. The John Henry Effect is when a group that is being studied puts forth more than usual effort in an attempt to outperform or exceed expectations (Baumgartner & Hensley, 2013). Avoiding the John Henry Effect could be done by assigning the times the different groups workout. The control being completely separate of the testing group.