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

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 a 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.

Repeatability and Meaningful Change of CPET Parameters in Healthy Subjects.

INTRODUCTION/PURPOSE: Cardiopulmonary exercise testing (CPET) plays an important role in clinical medicine and research. Repeatability of CPET parameters has not been well characterized, but is important to assess variability and determine if there have been meaningful changes in a given CPET parameter. METHODS: We recruited 45 healthy subjects and performed two symptom-limited CPET within 30 d using a cycle ergometer. Differences in relevant CPET parameters between CPET-1 and CPET-2 were assessed using a paired t-test. Coefficient of variation (CoV) and Bland-Altman plots are reported. Factors that may be associated with variability were analyzed (sex, age, time of day, fitness level). The coefficient of repeatability was calculated for peak oxygen consumption (V˙O2) and V˙O2 at lactate threshold (LT) to establish a 95% threshold for meaningful change. RESULTS: There were no significant differences between tests in the parameters reported. Specifically, we found overall low CoV in peak V˙O2 (4.9%), V˙O2@LT (10.4%), peak O2 pulse (4.6%), peak minute ventilation (V˙E; 7.4%), V˙E/V˙CO2@LT (4.0%), and V˙E/V˙O2@LT (4.8%). The CoV for peak respiratory exchange ratio@LT was significantly affected by diurnal factors; age, sex, and fitness level did not affect variability. The 95% threshold for meaningful change was 0.540 L·min in peak V˙O2 and 0.520 L·min in V˙O2@LT. CONCLUSIONS: Repeatability of CPET parameters is generally higher than previously reported. There were no significant differences in variability related to sex, age, and fitness level; diurnal factors had a limited effect. The threshold for meaningful change in peak V˙O2 and for V˙O2@LT should be considered when gauging a response to therapies or training.

Profiling the interest of general dental practitioners in West Yorkshire in using teledentistry to obtain advice from orthodontic consultants.

OBJECTIVE: To seek opinions from general dental practitioners in Calderdale and Kirklees (West Yorkshire) regarding an online orthodontic referral service and to establish the profile of dentists working in primary care who would refer patients online for a consultant orthodontist's opinion. METHODOLOGY: All 91 general dental practices in Calderdale and Kirklees in West Yorkshire were sent a piloted questionnaire enquiring into their orthodontic treatment and referral patterns, and also into their attitudes to the use of the Internet and related technologies. Three mailings were performed, followed by telephone contact with non-responders. RESULTS: Usable responses were obtained from 119 general dental practitioners who worked in 71 practices (78%). Analysis of data showed that, when asked whether they would be interested in using teledentistry to obtain a consultant orthodontist's opinion online, 53/116 (46%) replied positively. The most frequently specified reason for this interest was that it would save time and would achieve a quicker opinion for a practitioner's treatment plan. These dentists were more likely to be familiar with the use of digital cameras, be using removable appliances, and currently be in the habit of referring orthodontic cases to consultants and specialists. CONCLUSIONS: Just under half of the dentists working in primary care in Calderdale and Kirklees who responded had a positive attitude towards the benefits of a teledentistry referral scheme. However, a substantial number remained undecided, possibly because they were unsure of their information technology (IT) skills. A further pilot study is planned. It will enquire into the feasibility of carrying out such an exercise across West Yorkshire.