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The aim of this study was to determine the influence of swim intensity on acute responses to dynamic apnoea. 9 swimmers performed one 50 m front crawl trial in four different conditions: at 400 m velocity (V400) with normal breathing (NB), at V400 in complete apnoea (Ap), at maximal velocity (Vmax) with NB and at Vmax in Ap. Peak heart rate (HRpeak), blood lactate concentration after exercise (Lacpost ex) and Borg rating of perceived exertion (RPE) were measured. Arterial oxygen saturation (SpO2) was monitored with a pulse oximeter at forehead level during and after exercise. In Ap, swimming at V400 induced a significantly lower HRpeak and Lacpost ex than swimming at Vmax whilst RPE and the kinetics of SpO2 were not different at V400 and at Vmax. The minimal value of SpO2 in Ap was reached 10 to 11 s after the end of V400 and Vmax (81.7 ± 10.1% and 84.4 ± 10.6%, respectively). Swimming a 50 m front crawl in Ap resulted in a large decrease in SpO2 which occurred only after the cessation of exercise. The higher duration of apnoea during submaximal exercise could explain why SpO2 and RPE reached the same values as for maximal exercise.​ [ABSTRACT FROM AUTHOR]

Résumé: Introduction: Cette étude a pour objectif d’évaluer les effets de la cadence de pédalage (40 et 100rpm) sur le niveau d’oxygénation musculaire lors d’exercices à puissance constante. Les variations de l’hémoglobine déoxygénée (HHb) ont été mesurées par la technique de spectroscopie dans le proche infrarouge (NIRS). Méthodes et résultats: Douze sujets masculins actifs ont effectué une session comprenant deux exercices rectangulaires sur ergocycle à deux cadences différentes (40 et 100rpm). Les valeurs de HHb n’étaient pas significativement différentes lors des tests à 100rpm et à 40rpm, indiquant que l’extraction de l’O2 n’était pas modifiée par la cadence de pédalage. Conclusion: L’augmentation de la cadence de pédalage ne semble pas modifier l’équilibre entre la demande et l’apport d’O2 au niveau de la microcirculation. [ABSTRACT FROM AUTHOR]

The purpose of the study was to assess the effects of aerobic exercise training on saliva steroid hormones [i. e., cortisol, dehydroepiandrosterone (DHEA), and testosterone], physical capacity, and quality of life in obese diabetic men. 8 abdominally obese type 2 diabetic men (59.5 ± 1.7 years old, BMI = 35.5 ± 1.6 kg/m ², waist circumference = 119.4 ± 3.3 cm) and 9 healthy men (57.4 ± 1.5 years old, BMI = 24.5 ± 0.8 kg/m ², waist circumference = 92.3 ± 1.9 cm) participated in the study. The obese diabetic men underwent 8 weeks of aerobic exercise training: twice a week 45 min sessions at 75 % of peak heart rate and once a week 45 min session of intermittent exercise. Before and after training, steroid hormone concentrations were analyzed from saliva samples, physical capacity was assessed by the 6-minute walking test, and quality of life was estimated by a specific questionnaire for obese subjects. These data were compared with the data from the healthy untrained men. The basal saliva DHEA and testosterone concentrations, physical capacity, and quality of life scores of the obese diabetic men were significantly lower than those of the healthy men. Aerobic training induces a significant increase in the 6-min walking distance and improve the psychosocial impact dimension of quality of life, without modifying significantly any other parameter investigated. These data suggest that an 8-week aerobic exercise program improves physical capacity and quality of life in obese diabetic men, but was insufficient to correct the anthropometric and hormonal alterations observed in this population. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate serum and saliva adrenocortical hormones and their relationships at rest and during submaximal exercise and recovery in 9 obese diabetic middle-aged men (BMI: 35.2�1.6 kg/m2). Blood and saliva samples were taken at rest, every 10 min of a 30-min cycling exercise at 70% of maximal heart rate, and after 10 min of recovery in order to analyze cortisol, dehydroepiandrosterone sulfate (DHEA-S) and dehydroepiandrosterone (DHEA). Serum and saliva cortisol increased significantly during recovery (p<0.05), but no significant difference was observed between the rest, exercise, and recovery DHEA-S and DHEA concentrations. A strong correlation was found at rest between both serum and saliva cortisol (r=0.72, p<0.001) and DHEA-S and DHEA (r=0.93, p<0.001). Serum DHEA-S and saliva DHEA remained strongly correlated during and after the submaximal exercise (r=0.81, p<0.001), whereas a weaker but still significant relationship was observed between serum and saliva cortisol during and after the exercise (r=0.52, p<0.001). In conclusion, these results suggest that saliva adrenocortical hormones, and especially saliva DHEA, may offer a practical surrogate for serum concentrations during both rest and exercise in obese diabetic men. [ABSTRACT FROM AUTHOR]

Purpose: People with obesity have varying degrees of cardiovascular, pulmonary, and musculoskeletal dysfunction that affect aerobic exercise testing variables. Short time after bariatric surgery, these dysfunctions could affect both peak oxygen consumption ([Formula: see text] O 2 peak), the gold standard for assessing cardiorespiratory fitness (CRF) and aerobic capacity evaluated with ventilatory threshold (VT1). The purpose of this study was to evaluate the short-term effect of bariatric surgery, i.e. before the resumption of physical activity, on submaximal, at VT1 and maximal cardiorespiratory responses in middle-aged women with severe obesity., Materials and Methods: Thirteen middle-aged women with severe obesity (age: 36.7 ± 2.3 years; weight: 110.5 ± 3.6 kg, BMI: 41.8 ± 1.1 kg/m 2 ) awaiting bariatric surgery participated in the study. Four weeks before and 6 to 8 weeks after surgery, body composition was determined by bioelectrical impedance. The participants performed an incremental cycling test to [Formula: see text] O 2 peak., Results: After bariatric surgery, all body composition parameters were reduced, absolute [Formula: see text] O 2 peak and peak workload decline with a lower VT1. Relative [Formula: see text] O 2 at peak and at VT1 (ml/min/kg or ml/min/kg of FFM) remained unchanged. Ventilation was lower after bariatric surgery during exercise with no change in cardiac response., Conclusion: Our results showed that weight loss alone at short-term after bariatric surgery decreased CRF as seen by a decrease in absolute [Formula: see text] O 2 peak, and peak workload with lower VT1, whereas relative [Formula: see text] O 2 (ml/min/kg or ml/min/kg of FFM) during exercise remained unchanged in women with obesity. Rapid FFM loss affects cardiorespiratory responses at submaximal and maximal., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: Although it is well established that physical activity (PA) may partially correct the metabolic and hormonal alterations observed in patients with obesity, knowledge of its impact after bariatric surgery (BS) remains poor. The purpose of this study was to assess the repercussions of physical training on cortisol and testosterone responses in post-BS women., Materials and Methods: According to a randomized clinical trial, a PA group (11 women) started a 3-month physical training 6 weeks after BS, whereas no specific activity was proposed to a control group (9 women). Submaximal exercise (i.e., 30 min at 60% VO 2 peak) was performed by all subjects just before and after the 3-month period. Blood samples were taken at rest, after 10, 20, and 30 min of exercise and 10 min of passive recovery for cortisol and testosterone analyses. Blood glucose, blood lactate, and heart rate were assessed at the same time., Results: Before the program, a significant increase in cortisol, blood lactate, and heart rate was observed in all subjects during the submaximal exercise vs. rest, with no change in blood glucose and testosterone. After vs. before the 3-month period, no modification in any parameter was noted at rest in either group. However, during exercise, lack of cortisol increase and lower heart rate were found in the PA group only, with disappearance of the increase in blood lactate in both groups., Conclusion: Our results show some beneficial effects of physical training on hormonal and physical parameters. Further studies are needed to determine the biological and clinical significance of these adaptations induced by physical training in women after BS., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: The aim of this study was to evaluate the impact of short-term therapeutic hydrocortisone intake on pituitary and adrenal function in healthy young male subjects., Methods: Ten physically active men received 50 mg/per day of hydrocortisone at 8:00 a.m. for 5 days. Cortisol, DHEA, and ACTH concentrations in plasma, and cortisol and DHEA concentrations in saliva were determined the week before, just before (8:00 a.m.) and 2 h after (10:00 a.m.) drug ingestion on days 1, 3, and 5 of treatment and day 1 post treatment., Results: Hydrocortisone intake induced a significant increase in both plasma cortisol (×3) and saliva cortisol (×10) concentrations 2 h after administration. Plasma and saliva DHEA concentrations were significantly decreased, as were plasma ACTH concentrations, 2 h after administration, with an increase in the cortisol/DHEA and cortisol/ACTH ratios. However, no change in cortisol, DHEA, ACTH, cortisol/DHEA, or cortisol/ACTH was observed 24 h after the last intake during treatment or post treatment, except for a downward trend in saliva DHEA at days 3 and 5. The correlations between plasma and saliva cortisol, DHEA, and cortisol/DHEA were significant: respectively, r = 0.80, r = 0.80, and r = 0.88., Conclusions: Once-daily oral therapeutic administration of hydrocortisone for 5 days altered adrenal DHEA secretion by inhibiting pituitary ACTH, but this effect seemed transient without significant impairment of basal adrenal or pituitary function 24 h after administration. Given the high correlations between plasma and saliva, saliva samples may be offered as a sensitive surrogate for blood sampling to estimate adrenal and pituitary function.

The aim of the present study was to examine the effect of 1- and 2-day adventure races on cardiac muscle damage and skeletal muscle soreness and function in young athletes. Twelve male trained adolescents (14-15 years) completed both 1-day (48.2 km) and 2-day (66.0 km) races that included trail running, mountain biking, kayaking, and in-line skating separated by 10 weeks. Myocardial damage biomarker concentrations (cTnI and CK-MB), maximal voluntary isometric contraction (MVIC) torque, perceived knee extensor (KE) muscle soreness (PMS), and drop and squat jump heights were measured before and after each race. Heart rate was also monitored throughout. Mean heart rate (% cardiac reserve) was higher during the 1-day (66.6 ± 6.4%) than 2-day (62.6 ± 7.8%, p = 0.038) race. The amplitude of cardiac damage biomarker release was also higher following the 1-day than the 2-day race (peak cTnI: 0.14 vs. 0.03 ng/mL, p = 0.045; peak CK-MB: 20.30 vs. 11.98 ng/mL, p = 0.020). However, cardiac biomarker concentrations returned to baseline at 24-48 h post-exercise, except for CK-MB after the 2-day race ( p = 0.017). Eight and three participants exceeded the cTnI cut-off for myocardial injury in 1- and 2-day races, respectively, but none exceeded the cut-off for acute myocardial infarction. While there was a significant decrease in drop jump height (-5.9%, p = 0.003), MVIC torque and squat jump height remained unchanged after both races. PMS was increased at 24 h after both races ( p < 0.001) but returned to baseline levels by 72 h post-race. In conclusion, the shorter, more intense race produced more cardiac damage, although this probably represents a standard exercise intensity-dependent response rather than pathological response. Skeletal muscle functional and soreness responses were moderate and similar between races., (Copyright © 2020 Birat, Bourdier, Dodu, Grossoeuvre, Blazevich, Amiot, Dupont, Nottin and Ratel.)

The aim was to assess the cardiac, arterial oxygen saturation, lactate, hormonal and Borg rating of perceived exertion (RPE) responses to acute apnea in relation to apnea capacity in 18 middle-aged triathletes. Subjects were monitored while swimming two 50-m freestyle exercise trials with fins at maximal speed: with normal frequency breathing (NB) and with complete apnea (Ap); the latter was used to assess apnea capacity. The subjects with significant alteration in swimming performance inducing a time increase greater than 2.5% during Ap vs. NB were put in the group: bad apnea capacity (Bad Ap); the others, who showed no significant alteration in performance, were put in the group: Good Ap. Under apnea, both groups showed a decrease in arterial oxygen saturation (p<0.05). In Ap conditions, only Bad Ap had a significant lower maximal heart rate vs. NB (p<0.05), with lower blood lactate (p<0.05) and arm stroke frequency (p<0.01). No change in saliva hormonal concentrations was found during the experiment for both groups, whereas RPE responses were increased in the Good Ap group under Ap vs. NB conditions. In conclusion, a good apnea capacity seems to be associated with lower cardiovascular and metabolic apnea alterations in middle-aged recreationally-trained triathletes., Competing Interests: Conflict of Interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper., (© Georg Thieme Verlag KG Stuttgart · New York.)

Bone destruction is a hallmark of chronic rheumatic diseases. Although the role of osteoclasts in bone loss is clearly established, their implication in the inflammatory response has not been investigated despite their monocytic origin. Moreover, specific markers are lacking to characterize osteoclasts generated in inflammatory conditions. Here, we have explored the phenotype of inflammatory osteoclasts and their effect on CD4 + T cell responses in the context of bone destruction associated with inflammatory bowel disease. We used the well-characterized model of colitis induced by transfer of naive CD4 + T cells into Rag1 -/- mice, which is associated with severe bone destruction. We set up a novel procedure to sort pure osteoclasts generated in vitro to analyze their phenotype and specific immune responses by FACS and qPCR. We demonstrated that osteoclasts generated from colitic mice induced the emergence of TNFα-producing CD4 + T cells, whereas those generated from healthy mice induced CD4 + FoxP3 + regulatory T cells, in an antigen-dependent manner. This difference is related to the osteoclast origin from monocytes or dendritic cells, to their cytokine expression pattern, and their environment. We identified CX 3 CR1 as a marker of inflammatory osteoclasts and we demonstrated that the differentiation of CX 3 CR1 + osteoclasts is controlled by IL-17 in vitro. This work is the first demonstration that, in addition to participating to bone destruction, osteoclasts also induce immunogenic CD4 + T cell responses upon inflammation. They highlight CX 3 CR1 as a novel dual target for antiresorptive and anti-inflammatory treatment in inflammatory chronic diseases. © 2016 American Society for Bone and Mineral Research., (© 2016 American Society for Bone and Mineral Research.)

Purpose: The aim of this study was to compare the muscle oxygenation between trained and untrained subjects during heavy exercise until exhaustion at two extreme pedaling cadences using a NIRS system., Methods: Nine untrained male subjects and nine male competitive triathletes cycled until exhaustion at an intensity corresponding to 90 % of the power output achieved at peak oxygen uptake at 40 and 100 rpm. Gas exchanges were measured breath-by-breath during each exercise. Muscle (de)oxygenation was monitored continuously by near-infrared spectroscopy on the Vastus Lateralis., Results: Muscle deoxygenation (∆deoxy[Hb + Mb], i.e., O2 extraction) and ∆total[Hb + Mb] were significantly higher at 40 rpm compared to 100 rpm during the exercise in untrained subjects but not in triathletes (p < 0.05). The time performed until exhaustion was significantly higher at 40 than at 100 rpm in untrained subjects (373 ± 55 vs. 234 ± 37 s, respectively) but not in triathletes (339 ± 69 vs. 325 ± 66 s)., Conclusions: These results indicate that high aerobic fitness (1) allows for better regulation between [Formula: see text]O2M and VO2M following the change in pedaling cadence, and (2) is the most important factor in the relationship between pedaling cadence and performance.

This study examined the effect of pedal cadence on the heterogeneity of muscle deoxygenation during exercise of moderate intensity. Twelve healthy subjects performed 6 min of cycling at 40 and 100 r · min(-1) at 80% of the workload corresponding to the gas exchange threshold. Gas exchanges were measured breath by breath during each exercise. Muscle deoxygenation (HHb, i.e., O2 extraction) was monitored continuously by near-infrared spectroscopy at eight sites on the vastus lateralis. The heterogeneity of HHb was assessed using the relative dispersion of the signal measured at the eight sites (i.e., 100 × standard deviation/mean). HHb was not altered by the pedal cadence, whereas pulmonary V̇O2 was higher at 100 r · min(-1) than at 40 r · min(-1) (p < 0.001). The relative dispersion of HHb was significantly higher at 100 r · min(-1) than at 40 r · min(-1) (p < 0.001). These results indicate that pedal cadence has no effect on O2 extraction but that an elevated cadence would increase muscle V̇O2, suggesting an increase in muscle blood flow. Elevated cadence also induced greater heterogeneity of the muscle's V̇O2/Q̇O2 delivery ratio, suggesting a change in the adequacy between O2 demand and O2 delivery in some regions of active muscle.

Background: Many women are working outside of the home, occupying a multitude of jobs with varying degrees of responsibilities and levels of psychological stress. We investigated whether different job types in women are associated with child sex at birth, with the hypothesis that women in job types, which are categorized as "high psychological stress" jobs, would be more likely to give birth to a daughter than a son, as females are less vulnerable to unfavourable conditions during conception, pregnancy and after parturition, and are less costly to carry to term., Methods: We investigated the effects of mother's age, maternal and paternal job type (and associated psychological stress levels) and paternal income on sex ratio at birth. Our analyses were based on 16,384 incidences of birth from a six-year (2000 to 2005 inclusive) childbirth dataset from Addenbrooke's Hospital in Cambridge, UK. We obtained a restricted data set from Addenbrooke's hospital with: maternal age, maternal and paternal occupations, and whether or not the child was first-born., Results: Women in job types that were categorized as "high stress" were more likely to give birth to daughters, whereas women in job types that were categorized as "low stress" had equal sex ratios or a slight male bias in offspring. We also investigated whether maternal age, and her partner's income could be associated with reversed offspring sex ratio. We found no association between mother's age, her partner's job stress category or partner income on child sex. However, there was an important interaction between job stress category and partner income in some of the analyses. Partner income appears to attenuate the association between maternal job stress and sex ratios at moderate-income levels, and reverse it at high-income levels., Conclusions: To our knowledge this is the first report on the association between women's job type stress categories and offspring sex ratio in humans, and the potential mitigating effect of their partners' income.

The present study investigated whether short-term oral administration of glucocorticoid would modify performance and selected hormonal and metabolic parameters during submaximal exercise in healthy women. Nine recreational female athletes completed cycling trials at 70-75% VO(2) max until exhaustion after either placebo (Pla, gelatin) or oral prednisone (Cor, Cortancyl, 50 mg per day for 1 week) treatment, according to a double-blind and randomized protocol. Blood samples were collected at rest; after 10, 20, and 30 min of exercise; at exhaustion; and after 10 and 20 min of passive recovery for adrenocorticotrophic hormone (ACTH), dehydroepiandrosterone (DHEA), prolactin (PRL), growth hormone (GH), insulin (Ins), blood glucose (Glu), and lactate (Lac) determination. Cycling time was significantly increased with short-term Cor intake (Cor: 66.4 +/- 8.4 vs. Pla: 47.9 +/- 6.7 min, P < 0.01). ACTH and DHEA remained completely blunted throughout the experiment with Cor versus Pla (P < 0.01), whereas GH and PRL were significantly decreased with Cor after, respectively, 20 and 30 min of exercise (P < 0.05). No significant difference in Ins or Glu values was found between the two treatments but Lac concentrations were significantly increased with Cor versus Pla between 10 and 30 min of exercise (P < 0.05). These data indicate that short-term glucocorticoid intake improved endurance performance in women, but further investigation is needed to determine whether these results are applicable to elite female athletes and, if so, current WADA legislation needs to be changed.