Discussion
discomfort/pain
In accordance with our hypothesis, the results of the present study showed that the Low session led to a greater exercise volume compared to the Low + BFR and High sessions. Further, as expected, BFR training led to lower oxygen saturation than both High and Low and was perceived as less enjoyable than the High session. Of note, there was a tendency of Low + BFR also being perceived less enjoyable compared to the Low session, however the difference did not reach statistical significance (p = 0.051). Also, in accordance with our hypothesis, the results showed that performing finger flexor resistance training with low intensity (with and without BFR) until failure led to greater levels of discomfort compared to high intensity without BFR. Finally, as expected, there was no difference in perceived effort between the three sessions. However, and in contrast to our hypothesis, the high intensity sessions led to greater levels of lactate concentration compared to the other sessions and there was no difference in perceived session pleasure between the sessions.The difference in training volume between the two low intensity sessions is likely explained by an impaired recovery during the rest intervals both within and between the sets in the BFR sessionThe lack of difference in exercise volume between Low + BFR and High was accompanied by oxygen saturation and lactate pointing in different directions. Due to the lower levels of oxygen saturation after Low + BFR, it was at first glance surprising to observe that the High session led to the highest accumulation of lactate. However, a higher load and the same volume (time) means the energy turnover was higher at High than Low + BFR and lactate is directly related to the glycolytic rateIn the present study, the training volume in the BFR session was greater compared to the high intensity session after the two first sets, but not after the final set (although a statistical trend was observed). This could indicate that when multiple finger flexor sets are conducted using low intensity and BFR, the training volume progress to become relatively similar to the exercise volume using high intensity without BFR. This could be of great interest for climbers, since finger flexor strength has been identified as an important factor for performanceThe RPD findings showing greater rating for Low + BFR than High are in line with previous studies reporting that conducting BFR training leads to an increased level of discomfort/pain compared to free flowThe increased enjoyment after the High vs. the Low + BFR session could be explained by the difference in discomfort. However, based on this assumption, we would also expect a difference in EES between the Low and the High session, which was not observed. Instead, the difference in EES might be explained by the BFR per se. Although not reaching statistical significance, there seems to be a meaningful difference also between the two Low-sessions (p = 0.051, ES = 0.67). Importantly, none of the participants were accustomed to performing BFR-training. Although they did conduct a familiarization session, it may not be sufficient to familiarize with wearing the inflated cuff. Therefore, having inflated cuffs on their upperarm may have affected the participants` experience of the training, making it less enjoyable. Our finding is in accordance with Suga et al.The similarities in RPE were as expected and can be explained by the fact that all sets in all three sessions were performed until momentary failure. Hence the exertion is expected to be similarThe study has several limitations. First, the participants in the study were active male climbers at an advanced level and the findings can not necessarily be generalized to other populations. Second, the rest intervals between the sets in the high intensity and the two intensity sessions were different, which may have affected the results. Also, the training volume was not equated and consequently the effect of the BFR cannot be isolated. Importantly, the design is similar to previous studiesIn conclusion, performing a finger flexor resistance training session with low intensity and BFR led to a similar exercise volume but was perceived as more discomforting and less enjoyable than the high intensity session in advanced male climbers. Performing the session with low intensity without BFR yielded similar affective responses as the low intensity with BFR but required a much greater exercise volume. These findings suggest that active climbers who want to reduce the mechanical stress on the fingers should prioritize low intensity BFR-training for the specific finger flexor resistance training. However, one should be aware that this training may be perceived as more discomforting and less enjoyable than the more traditional high intensity resistance exercise. Future studies should compare the long-term effects of finger flexor resistance training performed with either low intensity and BFR or high intensity without BFR in climbers.