Effects of sprint interval training on cardiorespiratory fitness while in a hyperbaric oxygen environment

Abstract

Objectives: Hyperbaric oxygen (HBO2) exposure may enhance cardiorespiratory fitness. Exercise training and HBO2 exposure stimulate mitochondrial biogenesis, increase capillary density, and induce adaptive antioxidant mechanisms. We hypothesized that an exercise regimen of sprint interval training (SIT) while breathing HBO2 would lead to a greater improvement in exercise performance compared to the same training breathing ambient air. Methods: Healthy long-term intermediate-altitude residents, ages 20-39 years, with normal spirometry and cardiorespiratory fitness were randomized to two groups: one performing six sessions of an SIT regimen over two weeks in a hyperbaric chamber (1.4 ATA [141.9 kPa], FiO2=1.0); the other performing under ambient pressure conditions (0.85 ATA [86.1 kPa], FiO2=0.21). Training effect was evaluated by comparing incremental cycle ergometry cardiopulmonary exercise testing before and after the training regimen. The primary outcome measure was peak oxygen consumption (V̇O2), while secondary outcomes included additional exercise parameters. The effect of study group on exercise parameters was assessed using two-factor repeated measures ANOVA. Results: Of 58 participants randomized, 49 completed the training program and all cardiopulmonary exercise tests (n=23 HBO2, n=26 ambient). Both groups experienced an increase in peak V̇O2: 8.1% HBO2 and 7.1% ambient; the differences were not significant (p=0.50). Secondary parameters of peak work rate and peak V̇E experienced a significantly higher change in the HBO2 group compared to the ambient group (p=0.05 and p=0.03, respectively). Conclusion: Cardiorespiratory fitness improved after a two-week SIT regimen, but improvement in peak V̇O2 was not significantly different between ambient and HBO2 groups.

Effects of high-intensity interval training with hyperbaric oxygen

“…Hence, HIIT and HBO 2 together could synergistically increase PGC-1α and improve exercise capacity. However, HBO 2 showed a neutral effect on V_O 2 peak compared to HIIT alone (DeCato et al, 2019).…”

“…When administered in combination with moderate continuous training in athletes, it resulted in no additional improvements on V_O 2 peak compared with training under normoxic conditions (Burgos et al, 2016). However, in a more recent study, HBO 2 was administered in combination with high-intensity interval training (HIIT) and led to increased peak work rate and peak minute ventilation compared with air controls, but no differences in V_O2peak (DeCato et al, 2019). The underlying hypothesis is that the mitochondrial bioenergetic program is synergistically activated by these two stimuli, potentially via redox signaling.…”

“…In the present study we directly examined the combined effect of HBO 2 and HIIT on skeletal muscle bioenergetics as well as the attendant changes on V_O 2 peak during acute hypobaric hypoxia. We chose a HIIT regimen similar to that employed by DeCato, et al (DeCato et al, 2019), and measured changes in exercise capacity in a hypobaric hypoxic environment because hypoxic conditions (reduced oxygen supply) were believed to emphasize the role of peripheral determinants of V_O 2 (i.e. capillary surface area and mitochondrial capacity) more so than central determinants (i.e.…”

Does Hyperbaric Oxygenation Improve Athletic Performance?

“…DeCato et al (12) combined sprint interval training and breathing HBO at a pressure of 1.4 ATA during exercise (6 training sessions). V̇ o 2 max, TTE, HR max , HR at anaerobic threshold, work rate at anaerobic threshold, V̇ o 2 at anaerobic threshold, or ΔV o 2 /Δpower did not significantly differ after HBO training compared with training in NBA (12). On the other hand, peak work rate when exposed to HBO showed a trend toward higher values ( p = 0.05) (12).…”

“…Results of scarce number of studies assessing the combination of exercise training and HBO are inconsistent (6,12,21), despite seemingly the most promising protocol. An appealing hypothesis is a shift of the equilibrium between prooxidative and antioxidative states toward a favorable ratio (e.g., from a prooxidative to an antioxidative state) because both, HBO (applied intermittently and in a proper dosage) and chronic exercise, are known to increase the level of the antioxidant defense mechanisms on a long-term basis (11,16,22,25,55,71).…”