Boundary layer convective-like activity at Dome Concordia, Antarctica

The paper presents the micro-meteorological field experiment carried out at the plateau station of Dome Concordia (3300 m a.s.l.) during the Antarctic summer of 1997. The experiment dealt with the study of the trends of boundary layer features and the characteristics of the surface energy and momentum exchanges. A monostatic Doppler sodar, fast-response sensors and radiometers were used for this study. The experiment was part of a program that aims to assess the role of the continental polar regions in shaping the surface circulation over Antarctica. In spite of the markedly stable conditions found throughout the investigated period, some convective-like activity was detected during the warmer hours of the day

High-intensity interval training in polycystic ovary syndrome : A two-center, three-armed randomized

Purpose Exercise training is recommended to improve cardiometabolic health and fertility in women with polycystic ovary syndrome (PCOS), yet there are few randomized controlled trials on the effects of different exercise protocols on clinical reproductive outcomes. Our aim was to determine the effect of high-intensity interval training (HIT) on menstrual frequency, as a proxy of reproductive function, in women with PCOS. Methods The IMPROV-IT study was a two-center randomized controlled trial undertaken in Norway and Australia. Women with PCOS were eligible for inclusion. After stratification for body mass index <27 or ≥27 kg·m−2 and study center, participants were randomly allocated (1:1:1) to high-volume HIT (HV-HIT), low-volume HIT (LV-HIT), or a control group. Measurements were assessed at baseline, after the 16-wk exercise intervention, and at 12-month follow-up. The primary outcome was menstrual frequency after 12 months. Secondary outcomes included markers of cardiometabolic and reproductive health, quality of life, and adherence to and enjoyment of HIT. Results We randomly allocated 64 participants to the HV-HIT (n = 20), LV-HIT (n = 21), or control group (n = 23). There were no differences in menstrual frequency at 12 months between the LV-HIT and control groups (frequency ratio, 1.02; 95% confidence interval [CI], 0.73–1.42), the HV-HIT and control groups (frequency ratio, 0.93; 95% CI, 0.67–1.29), or the LV-HIT and HV-HIT groups (frequency ratio, 1.09; 95% CI, 0.77–1.56). Menstrual frequency increased in all groups from baseline to 12 months. More participants became pregnant in the LV-HIT group (n = 5) than in the control group (n = 0, P = 0.02). Conclusions A semisupervised HIT intervention did not increase menstrual frequency in women with PCOS. Clinical Trial Registration Number:ClinicalTrials.gov (NCT02419482)

The effects of high-intensity interval training on adipose tissue pathophysiology, reproductive and metabolic health in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in reproductive-aged women, affecting up to 13% of women worldwide and has wideranging reproductive, metabolic and psychological health implications. Still, the etiology and optimal therapies for PCOS remain unclear. Even if lifestyle modification, including exercise training, is the first-line therapy for improving reproductive, metabolic and psychological features in PCOS, there is currently no specific exercise prescription for the management of PCOS. Therefore, the primary aim of the IMproving Reproductive function in women with Polycystic OVary syndrome with high-intensity Interval Training (IMPROV-IT) trial (Paper I and II) was to investigate whether 16 weeks of either low-volume or high-volume semi-supervised high-intensity interval training (HIT), followed by subsequent 36 weeks of home-based HIT could increase menstrual frequency in women with PCOS during a 1-year period. Secondary aims were to examine the effects of HIT on cardiorespiratory fitness, rates of pregnancies, whole-body insulin sensitivity, and quality of life. IMPROV-IT was a two-center randomized controlled trial (RCT) that included 64 women with PCOS. The participants were randomly allocated (1:1:1) to either: lowvolume HIT (LV-HIT, 3 days/week of 10 x 1 min work bouts at maximal, sustainable intensity); high-volume HIT (HV-HIT, 3 days/week of 4 x 4 min work bouts at 90-95% of maximal heart rate); or non-exercise control (Non-Ex). Outcome measures were assessed at baseline, after 16 weeks and 12 months after baseline. The main findings in IMPROV-IT were that there were no between-group differences in menstrual frequency at 12 months but a significant increase in menstrual frequency from baseline to 12 months in all three groups including in the Non-Ex (control) group. Furthermore, pregnancy rates increased significantly after LV-HIT. Adherence to the exercise protocols was poor which may explain the lack of difference between groups in menstrual frequency as well as limited findings in secondary outcome measures (including insulin sensitivity and cardiorespiratory fitness). Quality of life improved in two out of five PCOS-related domains (infertility problems and body hair) in the HV-HIT group compared to the control group at 12 months follow-up. The complex relationship between multiple biological systems may partly explain the limited understanding of the etiology of PCOS. Adipose tissue dysfunction has been suggested to play a central role in the metabolic abnormalities observed in PCOS. The aims of Paper III and IV were to compare the expression of selected microRNAs in adipose tissue (and the circulation), fat cell size, rates of whole-body fat oxidation during submaximal exercise and rates of mitochondrial respiration in adipose tissue taken from women with and without PCOS. We also investigated the response to 16 weeks of HIT in these outcome measures in both groups of women. The main findings of Paper III were that the expression of circulating microRNA-27b was increased in PCOS, and that the expression of this microRNA was reduced after 16 weeks of LV-HIT. No differences were observed in the eight selected microRNAs in adipose tissue taken from women with and without PCOS, or following 16 weeks of LV- or HV-HIT. The main finding of Paper IV was that rates of whole-body fat oxidation during submaximal exercise only improved in women without, but not with PCOS, despite similar increases in cardiorespiratory fitness, indicating metabolic inflexibility in women with PCOS. Furthermore, we found that at baseline, women with PCOS had lower mitochondrial respiration through complex I + II in subcutaneous abdominal adipose tissue compared to women without PCOS, which supports the notion that abnormal adipose tissue may play a central role in PCOS pathophysiology

Absent exercise-induced improvements in fat oxidation in women with polycystic ovary syndrome after high-intensity interval training

Background: Polycystic ovary syndrome (PCOS) and metabolic inflexibility are linked to insulin resistance, and women with PCOS appear to be metabolic inflexible in the rested, insulin-stimulated state. Exercise training is a primary lifestyle intervention in PCOS. Exercise training improves whole-body fat oxidation during submaximal exercise in healthy women, yet little is known about the effect on this outcome in women with PCOS. Methods: We measured whole-body fat oxidation rates during sub maximal exercise before and after 16 weeks of high-intensity interval training (HIT) in women with PCOS randomly allocated to either: low- or high-volume HIT (n = 41; low-volume HIT, 10 × 1 min work bouts at maximal, sustainable intensity and high-volume HIT, 4 × 4 min work bouts at 90–95% of maximal heart rate) or non-exercise control (n = 23), and in women without PCOS (Non-PCOS) allocated to low- or high volume HIT (n = 15). HIT was undertaken three times weekly. In a subset of women with and without PCOS, we measured mitochondrial respiration in abdominal and gluteal subcutaneous adipose tissue using high-resolution respirometry, as well as fat cell sizes in these tissues. Results: At baseline, women with PCOS had lower whole-body fat oxidation and mitochondrial respiration rates in abdominal adipose tissue compared to Non-PCOS. Peak oxygen uptake (mL/min/kg) increased in women with PCOS (∼4%, p = 0.006) and Non-PCOS (∼6%, p = 0.003) after 16 weeks of HIT. Whole-body fat oxidation only improved in Non-PCOS after HIT. No changes were observed in mitochondrial respiration and cell size in abdominal and gluteal adipose tissue after HIT in either group of women. Conclusion: We observed exercise-induced improvements in whole-body fat oxidation Lionett et al. Metabolic Inflexibility in PCOS during submaximal exercise in Non-PCOS, but not in women with PCOS, after 16 weeks of HIT, suggesting metabolic inflexibility in women with PCOS

Improving reproductive function in women with polycystic ovary syndrome with high-intensity interval training (IMPROV-IT): study protocol for a two-centre, three-armed randomised controlled trial.

Introduction Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age and the leading cause of anovulatory infertility. Women with PCOS have a 15-fold higher prevalence of infertility, compared with women without PCOS, independent of body mass index (BMI). A healthy lifestyle is recommended to improve overall health and fertility in PCOS but there is limited evidence on the isolated effects of exercise, especially for reproductive outcomes. Previous findings indicate superior metabolic health benefits after vigorous compared with moderate-intensity exercise. Our primary aim is to determine the effect of high-intensity interval training (HIT) on menstrual frequency, as a proxy of reproductive function, in women with PCOS. Methods and analysis The study is a two-centre, randomised, controlled trial with three parallel groups. Women (n=64) from Trondheim (Norway) and Melbourne (Australia) with PCOS according to the Rotterdam criteria will be randomly allocated (1:1:1) to high-volume HIT, low-volume HIT or a control group with no exercise after stratifying for BMI < or ≥ 27 kg/m2 and study centre. Measurements for study end points will be undertaken at baseline, after a 16 week exercise intervention and at 12 months following baseline assessments. The primary outcome measure is menstruation frequency, measured as the number of self-reported menstrual bleedings divided by the number of expected menstrual bleedings during a 12-month period. Secondary outcome measurements include markers of cardiovascular, metabolic and reproductive health, as well as quality of life and adherence to and enjoyment of exercise. Ethics and dissemination The Regional Committee Medical Research Ethics, Norway, and The Australian Catholic University Human Research Ethics Committee, Australia, have approved the trial protocol. This trial will provide new insight regarding the impact of exercise on fertility in PCOS. We expect this trial to contribute to new therapeutic exercise strategies as part of clinical care for women with PCOS