A Review of the Health-Promoting Properties of Spirulina with a Focus on athletes' Performance and Recovery.

Spirulina species are photosynthetic and filamentous bacteria, commonly called 'blue-green microalgae'. Spirulina has a high nutrient content. It contains 60-70% protein with all essential amino acids present, and is rich in several vitamins, minerals, and bioactive compounds. Spirulina is also rich in essential fatty acids, and antioxidants. This rich nutritional content provides to Spirulina several health benefits including antioxidant, anti-inflammatory, immunomodulation, and insulin-sensitizing properties as well as positive effects in various diseases which could be also interesting for athletes. This paper mainly aims to review the interest and effects of Spirulina supplementation in athletes at rest, and in relation to exercise/training. Spirulina's biochemical composition, health properties/effects in humans, and effects in athletes including nutritional status, body composition, physical performance and intense exercise-related disorders were discussed in this review. Literature data showed that Spirulina seems to have positive effects on body composition especially in overweight and obese subjects which could not be the case in other pathologies and athletes. Spirulina appears to be also effective in improving aerobic fitness especially in untrained and moderately trained subjects. Results reported in the literature suggest that Spirulina may improve strength and power performance despite the minor or no significant effects in highly trained subjects. Most studies have shown that Spirulina improves antioxidant status, prevents and accelerates the recovery of exercise-induced lipid peroxidation, muscle damage and inflammation in trained and untrained subjects. Taken together, the results from these studies are encouraging and may demonstrate the potential benefits of Spirulina supplementation in athletes despite methodological differences.

Opioid use disorder in the active service: Implications for intervention.

BACKGROUND AND OBJECTIVES: Military service members experience occupational-specific injuries that may result in chronic pain and comorbid behavioral health concerns. METHODS: Data from the Defense Medical Epidemiology Database was used to examine opioid use disorder (OUD) diagnoses between 2016 and 2021. Statistical analysis calculated incidence rates and diagnostic variability by demographic density. RESULTS: The average incidence rate of OUD was 6.1 (per 10,000) and declined by 34% between 2016 and 2021. Diagnoses were most frequently made in service members classified as male, married, white, aged 30-39, junior enlisted, and serving in the Army. CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE: To our knowledge, this is the first study to examine the incidence rates of OUD among active duty personnel.

How are Canadian cannabis dispensaries counselling breastfeeding consumers?

Objectives: This study aimed to identify recommendations given to breastfeeding individuals by Canadian cannabis dispensary employees, since the legalization of recreational cannabis in 2018. Methods: This was a nationwide cross-sectional study conducted from November 2020 to January 2021. A mystery caller approach was used to identify recommendations given to breastfeeding individuals seeking a product for "relaxation." This study was modelled on similar studies which assessed recommendations given to pregnant women looking for cannabis products to manage nausea and vomiting (Vastis V, Shea AK, Vincent S, Metz TD. 275: Are canadian cannabis dispensaries counselling pregnant women appropriately? Am. J. Obstet. Gynecol. 2020;222: S187.(Abst). Lusero I, Paltrow LM, Rosenbloom N. Recommendations from cannabis dispensaries about first-trimester cannabis use Obstet Gynecol 2018;132:781-2.). The primary outcome was the recommendation of a cannabis product. Secondary outcomes included stated benefits of cannabis, recommended discussion with health care provider, length of call, rationale for recommendation, and reported source of information on which the recommendation was based. Results: The majority (79.4%) of employees of the 714 Canadian dispensaries contacted recommended against a cannabis product for "relaxation" while breastfeeding. The recommendations from dispensary employees were often (80%) provided without a specific reason, whereas a minority referenced published research (2%) and opinion (17.6%). Cannabis products were rarely (3.3%) classified as safe in breastfeeding. Approximately 76.6% of dispensary employees recommended contacting a health care provider, while 2.4% recommended against. Conclusions: Although a high proportion of dispensary employees recommended against using a cannabis product during lactation, there were still 20.6% that did recommend use, which contrasts the current public health guidelines and is not supported by the paediatric and obstetric societies. These findings highlight the need for further education about the safety of cannabis products while breastfeeding.

Spirulina supplementation prevents exercise-induced lipid peroxidation, inflammation and skeletal muscle damage in elite rugby players.

BACKGROUND: The present study aimed to examine the effects of spirulina supplementation on pro/antioxidant status, inflammation and skeletal muscle damage markers immediately and 24 h after exhaustive exercise in elite rugby players. METHODS: Seventeen elite male Rugby Union players were randomly assigned to a spirulina (SPI: n = 9) or placebo (PLA: n = 8) group in a double-blind design. Subjects were supplemented with Spirulina platensis (5.7 g day-1 ) or placebo (isoproteic and caloric) for 7 weeks. At baseline and after 7 weeks of supplementation, blood samples were obtained before (T0), immediately after (T1) and 24 h after (T2) exhaustive exercise. The Yoyo Intermittent Recovery Test Level 2 was used as an exhaustive exercise to induce oxidative stress (OS), inflammation and skeletal muscle damage. The studied parameters included pro/antioxidant status markers (superoxide dismutase, glutathione peroxidase, reduced glutathione/glutathione disulphide ratio, oxidised low-density lipoprotein and F2α-isoprostanes [F2-Isop]), inflammation markers (myeloperoxidase and C-reactive protein [CRP]) and skeletal muscle damage markers (lactate dehydrogenase and creatine kinase [CK]). RESULTS: Our results showed that F2-Isop, CRP and CK levels significantly increased at T1 only in the PLA group (p < 0.05, p < 0.05 and p < 0.001, respectively) with no change in the SPI group, which reflects the effect of spirulina to prevent lipid peroxidation, inflammation and skeletal muscle damage induced by exhaustive exercise. Moreover, spirulina supplementation accelerated the return to baseline values given that F2-Isop, CRP and CK levels at T2 were significantly lower than at T0 in the SPI group (p < 0.05, p < 0.01 and p < 0.001, respectively). CONCLUSIONS: Based on the markers used in the present study, our results show that spirulina supplementation potentially prevents exercise-induced lipid peroxidation, inflammation and skeletal muscle damage, and may also accelerate the recovery of some of these markers. Based on our findings, we recommend spirulina supplementation especially for those athletes who do not achieve the recommended antioxidant dietary intake and who perform a high training load aiming to reduce the magnitude of OS, inflammation and skeletal muscle damage, which could help to reduce performance losses and accelerate recovery after training/competitions throughout the season.

Spirulina platensis Provides a Small Advantage in Vertical Jump and Sprint Performance But Does Not Improve Elite Rugby Players' Body Composition.

The present study aimed to examine the effects of Spirulina supplementation on anthropometrical measurements and physical performance in elite rugby players. Twenty-two elite male Rugby Union players (21-36 years old) volunteered to participate in this study. They were randomly assigned to a Spirulina group (SPI: n = 11), or a placebo group (PLA: n = 11) in a double-blind design. Subjects were supplemented with Spirulina platensis (5.7 g/d) or placebo (isoproteic and caloric) for 7 weeks. At baseline (W0) and after 7 weeks of supplementation (W7), the same anthropometric measurements and physical performance test battery were performed. These tests included isokinetic leg strength and power, vertical jump, speed, and aerobic fitness assessment. For anthropometric data, the fat mass percentage was significantly reduced in both groups without significant difference between groups. While both groups exhibited significant improvements for Squat Jump (SJ), Countermovement Jump (CMJ), and 10- and 30-m sprints between W0 and W7, higher percentage improvements with the SPI group did not reach significance. Neither training alone (PLA) nor training associated with Spirulina supplementation affected leg maximal strength and power or aerobic fitness. Seven weeks of Spirulina supplementation in elite rugby players did not improve body composition or substantially increase physical performance. We only observed a non-significant small advantage in vertical jump and sprint performance in the SPI group. Based on the data from this study, Spirulina supplementation has modest effects in elite rugby players during the competitive phase. Further studies are required to verify Spirulina supplementation effects among athletes of different sports, ages, genders, and athletic levels with longer durations and higher dosages.

Are Canadian Cannabis Dispensaries Counselling Pregnant Women Appropriately?

Our objective was to examine the recommendations that Canadian dispensary employees are giving to women regarding cannabis use for nausea and vomiting of pregnancy (NVP) since the legalization of recreational cannabis in 2018. We conducted a nationwide cross-sectional study of licensed cannabis dispensaries in 2019, wherein a mystery caller stated they were 8 weeks pregnant and experiencing nausea and vomiting and asked for recommendations about cannabis. Our research was modeled after the primary study done in Colorado by Dickson and colleagues in 2018. An overwhelming majority of dispensaries (93%) in our study recommended against the use of a cannabis product for NVP, which contrasted significantly to the findings of the Colorado study, in which 70% of dispensaries recommended a cannabis product. These findings suggest that Canadian dispensary employees have been adequately educated about the dangers of cannabis use during pregnancy and are helpful from a public health lens.

Effect of pre-pregnancy body mass index on respiratory-related neonatal outcomes in women undergoing elective cesarean prior to 39 weeks.

Objective To examine the association between pre-pregnancy body mass index (BMI) and neonatal respiratory-related outcomes among women who underwent an elective cesarean section (CS). Methods A retrospective cohort study was conducted using the Centers for Disease Control and Prevention (CDC)'s 2009-2013 period linked birth/infant death dataset. Women who had elective CSs at term were categorized by their pre-pregnancy BMI as normal, overweight, obese or morbidly obese. Odds ratios (OR) and 95% confidence intervals (CIs), adjusted for baseline characteristics, were calculated using multivariate logistic regression to estimate the neonatal risks in relation to maternal pre-pregnancy BMI. Results Our cohort consisted of 717,080 women, of whom 39.9% had normal BMI, 27.0% were overweight, 25.7% obese and 7.4% morbidly obese. A dose-dependent relationship between maternal pre-pregnancy BMI and assisted ventilation was seen. Furthermore, infants born to morbidly obese women were at significantly increased risk for assisted ventilation over 6 h (OR 1.24, 95% CI 1.15-1.35) and admission to intensive care units (OR 1.17, 95% CI 1.13-1.21). Infant mortality rates were 4.2/1000 births for normal weight women, and 5.5/1000 births among the morbidly obese group (OR 1.43, 95% CI 1.25-1.64). Risk for adverse outcomes was increased with elective SC performed at earlier gestational age, and this effect was not modified by use of corticosteroids. Conclusion Overweight and obese women are at particularly greater risk of adverse newborn outcomes when elective CSs are done before 39 weeks. In these women, elective CSs should be delayed until 39 weeks, as corticosteroid use did not eliminate this association.

Risk Factors, Incidence, and Morbidity Associated With Obstetric Clostridium difficile Infection.

OBJECTIVE: To evaluate the risk factors, incidence, and morbidity associated with the diagnosis of obstetric Clostridium difficile infection. METHODS: We performed a retrospective cohort study on women admitted for delivery using the Healthcare Cost and Utilization Project Nationwide Inpatient Sample from the United States. The delivery admission records of pregnant women were reviewed between 1999 and 2013. After adjusting for demographic and clinical characteristics, we assessed risk factors for the diagnosis of C difficile infection using unconditional logistic regression. RESULTS: Of the total 13,881,592 births in our cohort, we identified 2,757 (0.02%) admissions for delivery complicated by a diagnosis of C difficile infection. During the study period, the rate of C difficile infection diagnoses among women hospitalized for delivery doubled from 15 (95% CI 11.87-16.96) to 30 (24.42-31.78) per 100,000 deliveries per year (P<.001). Risk factors associated with the diagnosis of C difficile infection included age older than 35 years, multiple gestations, smoking, Crohn's disease, ulcerative colitis, long-term antibiotic use, pneumonia, pyelonephritis as well as cesarean or perineal wound infection. The diagnosis of C difficile infection in pregnancy was associated with a significant increase in maternal death (8.0/1,000 vs 0.1/1,000, adjusted odds ratio [OR] 56.8, 95% CI 35.8-90.1). Furthermore, there was an increase in sepsis (46.4/1,000 vs 0.6/1,000, adjusted OR 59.1, 95% CI 48.8-71.6), paralytic ileus (58.0/1,000 vs 1.5/1,000, adjusted OR 33.1, 95% CI 27.5-39.8), venous thromboembolism (38.4/1,000 vs 3.1/1,000, adjusted OR 8.1, 95% CI 6.5-10.2), and hospital stays greater than 2 weeks (173.0/1,000 vs 6.5,1,000, adjusted OR 24.3, 95% CI 21.6-27.4) among pregnant women with C difficile infection. CONCLUSION: The diagnosis of C difficile infections in pregnancy has increased over the past 15 years and this diagnosis is associated with significant maternal morbidity and mortality.

Meta-Analysis of Randomized Controlled Trials Comparing the Long-Term Outcomes of Carotid Artery Stenting Versus Endarterectomy.

BACKGROUND: Stenting is an endovascular alternative to endarterectomy for the management of carotid stenosis, but its long-term safety and efficacy relative to endarterectomy remain unclear. Our objective was to compare the safety and efficacy of stenting with those of endarterectomy, with a particular focus on long-term outcomes, via meta-analysis of randomized controlled trials (RCTs). METHODS AND RESULTS: We systematically searched PubMed, EMBASE, MEDLINE, and the Cochrane Library for RCTs with ≥50 patients that compared stenting with endarterectomy in patients with carotid stenosis. Periprocedural and long-term outcomes were assessed, with data pooled across RCTs using random-effects models. Eight RCTs were included in our meta-analysis (n=7091), with follow-up ranging from 2.0 to 10.0 years. When compared with endarterectomy, stenting was associated with an increased risk of periprocedural stroke (relative risk, 1.49, 95% confidence interval [CI], 1.11 to 2.01; risk difference, 1.7%; 95% CI, 0.3 to 3.0) but a decreased risk of periprocedural myocardial infarction (relative risk, 0.47; 95% CI, 0.29 to 0.78; risk difference, -0.4%; 95% CI, -0.8% to 0.1%). During long-term follow-up, stenting was associated with an increased risk of stroke (relative risk, 1.36; 95% CI, 1.16 to 1.61) and a composite end point of ipsilateral stroke, periprocedural stroke, or periprocedural death (relative risk, 1.45; 95% CI, 1.20 to 1.75). CONCLUSIONS: Although stenting has more favorable periprocedural outcomes with respect to myocardial infarction, the observed increased risk of stroke and death throughout follow-up with stenting suggests that endarterectomy remains the treatment of choice for carotid stenosis.

Dietary α-lactalbumin supplementation alleviates normocaloric western diet-induced glucose intolerance in Göttingen minipigs.

OBJECTIVE: The pandemic of obesity in Western countries is mainly due to the high-fat, high-energy diet prevailing there. Obesity-associated metabolic disorders are the consequence of fat mass increase leading to altered adipokine secretion, hyperlipemia, oxidant stress, low-grade inflammation, and eventually glucose intolerance. Yet not all people consuming a Western diet become obese, and the question is raised whether these people are also at risk of developing metabolic disorders. METHODS: Glucose tolerance, lipid profile, and oxidant and inflammation status were investigated longitudinally in lean Göttingen minipigs receiving for 16 weeks either a normal diet (ND), a Western diet (WD), or a Western diet supplemented with a whey protein isolate (WPI) rich in α-lactalbumin known to improve glucose tolerance. ND and WD were supplied isoenergetically. RESULTS: Lean minipigs fed WD displayed glucose intolerance and altered lipid profile after 6 weeks of diet but no inflammation or oxidative stress. Supplementation with WPI alleviated glucose intolerance by improving insulin secretion, but not lipid profile. CONCLUSIONS: Western diet consumption is deleterious for glucose tolerance even in the absence of fat mass accretion, and dyslipemia is a major determinant for this metabolic dysfunction. Stimulating insulin secretion with a WPI is an effective strategy to improve glucose tolerance.

Fermented soy permeate reduces cytokine level and oxidative stress in streptozotocin-induced diabetic rats.

Oxidative stress and inflammation are involved in the development of type 1 diabetes and its complications. Because two compounds found in soy, that is, isoflavones and alpha-galactooligosaccharides, have been shown to exert antioxidant and anti-inflammatory effects, this study aimed to assess the effects of a dietary supplement containing these two active compounds, the fermented soy permeate (FSP). We hypothesized that FSP would be able to reduce in vivo oxidative stress and inflammation in streptozotocin (STZ)-induced type 1 diabetic rats. Thirty male Wistar rats were divided into the control placebo, diabetic placebo, and diabetic FSP-supplemented groups. They received daily, by oral gavage, water (placebo groups) or diluted FSP (0.1 g/day; FSP-supplemented group). After 3 weeks, glycemic regulation (glycemia and fructosamine level); the plasma level of carboxymethyllysine (CML), a marker of systemic oxidative stress in diabetes; and the plasma levels of inflammatory markers (CRP, IL-1ß, IL-6, and uric acid) were evaluated. Markers of oxidative damage (isoprostanes and GSH/GSSG), antioxidant enzymatic activity (SOD and GPX), and Mn-SOD content were determined in skeletal muscle (gastrocnemius). Diabetic placebo rats exhibited higher CML levels, lower SOD and GPX activities, and decreased Mn-SOD contents. FSP supplementation in diabetic animals normalized the CML and antioxidant enzymatic activity levels and tended to increase Mn-SOD expression. The markers of inflammation whose levels were increased in the diabetic placebo group were markedly decreased by FSP (IL-1ß: -75%, IL-6: -46%, and uric acid: -17%), except for CRP. Our results demonstrate that FSP exhibited antioxidant and anti-inflammatory properties in vivo in STZ-induced diabetic rats.

Exercise training combined with antioxidant supplementation prevents the antiproliferative activity of their single treatment in prostate cancer through inhibition of redox adaptation.

In preclinical models, exercise training (ET) or pomegranate juice (PJ) prevents prostate cancer progression. Here, we hypothesized that physical exercise combined with antioxidants could induce synergistic effects through oxidative stress modulation. Forty male Copenhagen rats with prostate tumors were divided into four groups: control, PJ, ET, and PJ+ET. Rats from the PJ group consumed 750 µl of PJ daily, rats from the ET group ran on a treadmill 5 days per week, and PJ+ET rats received the combined treatment. Each week, tumor growth was evaluated. After 4 weeks of treatment, the rats were euthanized and blood, muscles, and tumors were collected. Tumor Ki67, extracellular signal-regulated kinase (ERK) activation, Bcl-2 expression, and enzymatic and nonenzymatic antioxidant defenses, as well as oxidative stress markers (oxidized base, lipid peroxidation, protein carbonylation), were measured. PJ or ET significantly decreased prostate tumor proliferation (Ki67 staining, p<0.05) through the modulation of ERK phosphorylation, whereas the combination of treatments did not limit cancer progression. PJ significantly reduced Bcl-2 expression in tumors (p<0.05) and the combination of PJ and ET prevented this effect. PJ or ET increased enzymatic antioxidant defenses in muscle, PJ increased nonenzymatic antioxidant defenses in plasma and whole blood. In addition, PJ reduced TBARS and 8-oxodGuo levels in tumors as well as ET (p<0.05), whereas protein carbonyl levels were not affected by these two strategies. Paradoxically, association of PJ+ET did not increase antioxidant defenses and no reduction in oxidative stress markers was induced. Loading cancer cells with antioxidants blunts the positive effects of ET and interferes with important reactive oxygen species-mediated physiological processes such as antioxidant adaptations.

Antioxidants and muscle atrophy in colon cancer: beneficial or deleterious effects?

Cancer cachexia is a multifactorial syndrome characterized by an ongoing loss of body weight, mainly due to adipose tissue and skeletal muscle wasting. Muscle atrophy leads to a progressive functional impairment and contributes to a negative impact on patient's quality of life. Oxidative Stress (OS) seems to play a major role in muscle atrophy since OS markers are increased in plasma and muscles of cancer patients. Thus, supplementing patients with antioxidant may reduce OS and restore muscle mass and function. In this study, we assess the effects of antioxidant supplementation on muscle atrophy in a model of colon 26 tumor-bearing mice (C26-mice). Five-week old Balb/c mice receive a subcutaneous injection of PBS or C26 cancer cells with or without daily supplementation with Allopurinol or Oxynov (50mg/kg and 163mg/kg respectively). Blood and muscles are removed 20-22 days after injection. C26-mice develop cachexia, with a decrease in total body weight, muscular endurance and muscle fibers diameter. Furthermore, injection of C26 induces ubiquitination of muscles proteins, suggesting the enhancement of muscle proteolysis. Contrary to our expectations, supplementation with antioxidants (Allopurinol or Oxynov) doesn't prevent weight loss and muscle atrophy but induces premature death of mice. C26-mice exhibit systemic oxidative stress markers (i.e. carbonyl proteins and 4-HNE) and show an increase in phosphorylation levels of the redox-dependent kinase, JNK, in the atrophied muscles (i.e. gastrocnemius). Surprisingly, Allopurinol or Oxynov decrease the total antioxidant defenses in plasma but has no effect on C26-induced oxidative damages and JNK phosphorylation. Our results are in agreement with recent reports showing deleterious effects of antioxidants supplementation in lung and prostate cancer. However, such findings require further investigations.

Intense exercise training is not effective to restore the endothelial NO-dependent relaxation in STZ-diabetic rat aorta.

BACKGROUND: The aim of this study was to examine the effects of intense physical training on vascular function in streptozotocin-diabetic rats. We focused on the endothelium-dependent relaxation (EDR) induced by acetylcholine (ACh) and stable ADP adenosine-5'- O - (2-thiodiphosphate) (ADPßS). METHODS: Control or diabetic male Wistar rats (n=44) were randomly assigned to sedentary or trained groups. The training program consisted in a regular period of running on a treadmill during 8 weeks (10° incline and up to 25 m/min, 60 min/day). The reactivity of isolated thoracic aorta rings of healthy, diabetic and/or trained has been tested. RESULTS: ACh and ADPßS-induced EDR were observed in phenylephrine (PE) pre-contracted vessels. As compared to sedentary control group, diabetic rats showed an increase in PE-induced contraction and a decrease in ACh and ADPßS-induced EDR (p<0.05). Moreover, there were no increase in ACh and ADPßS-induced EDR in diabetic rats. N-Nitro-L-Arginine Methyl Ester inhibited the nitric oxide synthase in diabetic and control rats, thereby resulting in a strong inhibition of the EDR induced by ACh and ADPßS (10-6 M). CONCLUSION: Diabetes induced an endothelium dysfunction. Nevertheless, our intense physical training was not effective to restore the aorta endothelial function.

A fermented soy permeate improves the skeletal muscle glucose level without restoring the glycogen content in streptozotocin-induced diabetic rats.

Exercise is essential into the therapeutic management of diabetic patients, but their level of exercise tolerance is lowered due to alterations of glucose metabolism. As soy isoflavones have been shown to improve glucose metabolism, this study aimed to assess the effects of a dietary supplement containing soy isoflavones and alpha-galactooligosaccharides on muscular glucose, glycogen synthase (GSase), and glycogen content in a type 1 diabetic animal model. The dietary supplement tested was a patented compound, Fermented Soy Permeate (FSP), developed by the French Company Sojasun Technologies. Forty male Wistar rats were randomly assigned to control or diabetic groups (streptozotocin, 45 mg/kg). Each group was then divided into placebo or FSP-supplemented groups. Both groups received by oral gavage, respectively, water or diluted FSP (0.1 g/day), daily for a period of 3 weeks. At the end of the protocol, glycemia was noticed after a 24-h fasting period. Glucose, total GSase, and the glycogen content were determined in the skeletal muscle (gastrocnemius). Diabetic animals showed a higher blood glucose concentration, but a lower glucose and glycogen muscle content than controls. Three weeks of FSP consumption allowed to restore the muscle glucose concentration, but failed to reduce glycemia and to normalize the glycogen content in diabetic rats. Furthermore, the glycogen content was increased in FSP-supplemented controls compared to placebo controls. Our results demonstrated that diabetic rats exhibited a depleted muscle glycogen content (-25%). FSP-supplementation normalized the muscle glucose level without restoring the glycogen content in diabetic rats. However, it succeeded to increase it in the control group (+20%).

Combined insulin treatment and intense exercise training improved basal cardiac function and Ca(2+)-cycling proteins expression in type 1 diabetic rats.

This study investigated the effects of 8 weeks of intense exercise training combined with insulin treatment on the Ca(2+)-cycling protein complex expression and their functional consequences on cardiac function in type 1 diabetic rat hearts. Diabetic Wistar rats were randomly assigned into the following groups: received no treatment, insulin-treated diabetic, trained diabetic, and trained insulin-treated diabetic. A control group was also included. Insulin treatment and (or) treadmill intense exercise training were conducted over 8 weeks. Basal cardiac function was evaluated by Langendorff technique. Cardiac expression of the main Ca(2+)-cycling proteins (RyR2, FKBP 12.6, SERCA2, PLB, NCX1) was assessed by Western blot. Diabetes altered basal cardiac function (±dP/dt) and decrease the expression of the main Ca(2+)-cycling proteins expression: RyR2, SERCA2, and NCX1 (p < 0.05). Whereas combined treatment was not able to normalize -dP/dt, it succeeded to normalize +dP/dt of diabetic rats (p < 0.05). Moreover, both insulin and intense exercise training, applied solely, increased the expression of the Ca(2+)-cycling proteins: RyR2, SERCA2, PLB. and NCX1 (p < 0.05). But this effect was higher when the 2 treatments were combined. These data are the first to show that combined insulin treatment and intense exercise training during diabetes synergistically act on the expression of the main Ca(2+)-cycling proteins, providing insights into mechanisms by which the dual treatment during diabetes improves cardiac function.

Inverse relationship between percentage body weight change and finishing time in 643 forty-two-kilometre marathon runners.

OBJECTIVE: The purpose of this study was to determine the relationship between athletic performance and the change in body weight (BW) during a 42 km marathon in a large cohort of runners. METHODS: The study took place during the 2009 Mont Saint-Michel Marathon (France). 643 marathon finishers (560 males and 83 females) were studied. The change in BW during the race was calculated from measurements of each runner's BW immediately before and after the race. RESULTS: BW loss was 2.3 ± 2.2% (mean±SEM) (p<0.01). BW loss was -3.1 ± 1.9% for runners finishing the marathon in less than 3 h; -2.5 ± 2.1% for runners finishing between 3 and 4 h; and -1.8 ± 2.4% for runners who required more than 4 h to complete the marathon. The degree of BW loss was linearly related to 42 km race finishing time (p<0.0000001). Neither age nor gender influenced BW loss during the race. CONCLUSIONS: BW loss during the marathon was inversely related to race finishing time in 643 marathon runners and was >3% in runners completing the race in less than 3 h. These data are not compatible with laboratory-derived data suggesting that BW loss greater than 2% during exercise impairs athletic performance. They match an extensive body of evidence showing that the most successful athletes in marathon and ultra-marathon running and triathlon events are frequently those who lose substantially more than 3-4% BW during competition.

Intense exercise training induces adaptation in expression and responsiveness of cardiac ß-adrenoceptors in diabetic rats.

BACKGROUND: Informations about the effects of intense exercise training on diabetes-induced myocardial dysfunctions are lacking. We have examined the effects of intense exercise training on the cardiac function of diabetic rats, especially focusing on the Langendorff ß-adrenergic responsiveness and on the ß-adrenoceptors protein expression. METHODS: Control or Streptozotocin induced-diabetic male Wistar rats were randomly assigned to sedentary or trained groups. The training program consisted of 8 weeks running on a treadmill (10° incline, up to 25 m/min, 60 min/day) and was considered to be intense for diabetic rats. RESULTS: This intense exercise training amplified the in vivo diabetes-induced bradycardia. It had no effect on Langendorff basal cardiac contraction and relaxation performances in control and diabetic rats. In diabetic rats, it accentuated the Langendorff reduced responsiveness to ß-adrenergic stimulation. It did not blunt the diabetes-induced decrease of ß1-adrenoceptors protein expression, displayed a significant decrease in the ß2-adrenoceptors protein expression and normalized the ß3-adrenoceptors protein expression. CONCLUSIONS: Intense exercise training accentuated the decrease in the myocardial responsiveness to ß-adrenergic stimulation induced by diabetes. This defect stems principally from the ß2-adrenoceptors protein expression reduction. Thus, these results demonstrate that intense exercise training induces specific effects on the ß-adrenergic system in diabetes.

Early advancing age alters plasma glucose and glucoregulatory hormones in response to supramaximal exercise.

After the age of 60, the decrease in physical activity and the increase in fat mass (FM) are two essential factors contributing to the alteration of glucose, insulin, and catecholamines responses induced by exercise. To discard these two factors, we compared the glucoregulatory responses in three different groups of men between the ages 21 and 34, and matched pairs: trained groups (T34 and T21) were matched for training level; T21 and U21 (U for untrained) were matched for age; T34 and U21 were matched for FM. The glucoregulatory responses were determined by venous plasma concentrations of glucose ([GLU]), insulin ([INS]), and catecholamines (adrenaline: [A], noradrenaline: [NA]) before and after a Wingate test. [GLU], [INS], and [A] did not differ between T21 and U21, indicating that high-level training had no effects on these parameters. On the other hand, T34 compared to T21 and U21, had higher GLU associated with lower INS post-exercise concentrations. Moreover, [A(max)] was significantly lower in this group. Consequently, T34 only exhibited a significant alteration in glucose and glucoregulatory responses after a Wingate test, which could not be explained by the usual decrease in physical activity and/or the increase in FM. Therefore, aging alone seems to be one main factor of this deterioration.

Nutritional and plasmatic antioxidant vitamins status of ultra endurance athletes.

OBJECTIVE: The "Marathon des Sables" (MDS) is a competition known to induce oxidative stress. Antioxidant vitamins prevent exercise-induced oxidative damages. The purpose of this study was to evaluate daily intake and plasma level of the main antioxidant vitamins (alpha-tocopherol, vitamin C, beta-carotene and retinol) in 19 male athletes who participated in this competition. METHODS: Data collected before the beginning of the competition included daily dietary intake using a 7-day food record and plasma biochemical measurements (alpha-tocopherol, vitamin C, beta-carotene and retinol). RESULTS: First, total energy intake was obviously lower than the energetic intake usually observed in well-trained endurance athletes. Second, antioxidant vitamins intake was also insufficient. Indeed, the intake was lower than the French Dietary Reference Intakes (DRI) for this population in 18 subjects for vitamin E and 6 subjects for vitamin C, beta-carotene and Retinol Equivalent. As a significant relationship was found between total energy intake and the intake of vitamin E (r = 0.73; p < 0.001) and vitamin C (r = 0.78; p < 0.001), the low total energy intake contributed partially to the insufficient antioxidant vitamins intake. The dietary questionnaire analysis also revealed a low intake of vegetable oils, fruits and vegetables. However, plasma concentrations of these antioxidant vitamins were similar to the literature data observed in athletes. CONCLUSION: This study evidenced obvious insufficient energy intake in ultra endurance athletes associated with a low antioxidant vitamin intake.