Limitations
CRF
CRF
The results and analyses of the present study should be considered with the following limitations in mind. First, the running group’s “all-out” modality limited the possibility of longer work durations and a higher number of intervals per session if the training volume was to be kept equal in both groups. This could have limited the intensity achieved in JT, given that more and longer work intervals would most probably have helped to increase cardiopulmonary demand and thus produce higher CRF improvements. Second, with the use of a portable spirometer and a heart rate monitor, we could have recorded oxygen uptake and heart rate during the running and jumping training sessions to assess the actual cardiopulmonary demand, instead of having to rely on the overall measure of RPE. Third, the significant difference in the female/male ratio as well as in body fat percentage between the groups at the beginning of the study is the result of the randomization process and might have had an effect on the results of the study in case men and women responded differently to this kind of training. Finally, the inclusion of a muscle endurance test and a repeated sprint test would have provided further insight into other training effects specific to the two training modalities.