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Evaluating the effects of oral contraceptive use on biomarkers and body composition during a competitive season in collegiate female soccer players

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Abstract

High training demands throughout the competitive season in female collegiate soccer players have been shown to induce changes in biomarkers indicative of stress, inflammation, and reproduction, which may be exacerbated in athletes using oral contraceptives (OCs). Purpose: To compare biomarkers and body composition between OC-using and non-using (CON) female soccer players throughout a competitive season. Methods: Female collegiate soccer players were stratified into two groups based on their reported OC use at the start of pre-season (OC: n=6; CON: n=17). Prior to the start of pre-season and immediately post-season, athletes underwent a battery of performance tests. Blood draws and body composition assessments were performed prior to pre-season, on weeks 2, 4, 8, and 12 of the season, and post-season. Results: Area-under-the-curve ratios (OCAUC:CONAUC) indicated the OC group were exposed to substantially higher levels of sex-hormone binding globulin (AUCratio=1.4, probability=p>0.999), total cortisol (1.7; p>0.999), c-reactive protein (5.2; p>0.999), leptin (1.4; p=0.990), growth hormone (1.5; p=0.97), but substantively lower amounts ofestradiol (0.36; p<0.001),progesterone (0.48; p=0.008), free testosterone (0.58; p<0.001), follicle-stimulating hormone (0.67; p<0.001) and creatine kinase (0.33, p<0.001) compared with the CON across the season. Both groups increased fat free mass over the season, but CON experienced a greater magnitude of increase along with decreased body fat percentage. Conclusion: Although similar training loads were observed between groups over the season, the elevated exposure to stress, inflammatory, and metabolic biomarkers over the competitive season in OC users may have implications on body composition, training adaptations, and recovery in female athletes.

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... The differing profiles of HCs may produce variations in their physiological effects and subsequent side-effects, and therefore, may differ in their potential influence on athletic performance [15]. There is equivocal evidence regarding the influence of hormonal contraceptives on exercise performance and chronic training adaptations, with studies reporting HC-use having a positive, negative and neutral influence on adaptation to resistance training [16][17][18][19][20][21]. ...
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In order to validate the use of heart rate (HR) in describing and monitoring physiological demands during soccer activities, the HR versus oxygen uptake ( V(.)O(2)) relationship determined on the field during soccer-specific exercises was compared to that found in the laboratory during treadmill exercise. Seven male amateur soccer players [mean (SE), age 25.3 (1.2) years, body mass 72.9 (2.1) kg, stature 1.76 (0.03) m] performed three trials on the field (two laps of a purpose-made circuit including a variety of soccer activities) at different intensities (moderate, high and very high, according to their rate of perceived exertion) and an incremental test on a treadmill in the laboratory. HR increased linearly with V(.)O(2) during both field and laboratory tests according to exercise intensity ( P<0.01). The mean correlation coefficients of the HR- V(.)O(2) relationships obtained in the laboratory and on the field were 0.984 (0.012) and 0.991 (0.005) ( P<0.001), respectively. The mean value of the HR- V(.)O(2) regression equation slope and intercept obtained in laboratory [0.030 (0.002) and 79.6 (4.6), respectively] were not significantly different compared to those found on the field [0.032 (0.003) and 76.7 (9.7)]. The present study seems to confirm that HR measured during soccer exercises effectively reflects the metabolic expenditure of this activity. Thus, with the aid of laboratory reference tests, the physiological demands of soccer activities can be correctly estimated from HR measured on the field in amateur soccer players.
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Menstrual disturbances are common among female athletes, and oral contraceptives (OCs) are often recommended as estrogen substitution. However, there is little information about the effects of OC use in athletes, and there is great concern that OCs might impair physical performance. The aim of this study was to investigate the effects of OC use on body composition and physical performance in female athletes. Twenty-six endurance athletes (13 with oligo-/amenorrhea and 13 regularly menstruating athletes) and 12 sedentary controls were examined before and after 10 months of treatment with a low dose, monophasic, combined OC. Significant changes in body composition were recorded in the athletes, but not in the controls. There was an increase in weight and fat mass only in athletes with oligo-/amenorrhea. These changes were associated with a decrease in ovarian androgens. OC treatment also increased bone mineral density, with the largest increase in athletes with a low bone mineral density at baseline. Despite significant changes in body composition, little impact on physical performance was recorded. We have demonstrated that OC treatment in female athletes has predominantly beneficial effects on body composition without adverse effects on physical performance and could be used for the prevention of osteoporosis in athletic amenorrhea. However, it cannot be excluded that a marked increase in fat mass might have unfavorable effects for athletic performance in individual women.
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McFadden, BA, Walker, AJ, Bozzini, BN, Sanders, DJ, and Arent, SM. Comparison of internal and external training loads in male and female collegiate soccer players during practices vs. games. J Strength Cond Res XX(X): 000-000, 2020-The purpose of this study was to compare the internal and external training loads (TLs) in men and women throughout a Division I soccer season during practices versus games. Players were evaluated during all practices and regulation game play using the Polar TeamPro system, utilizing Global Positioning Satellite technology and heart rate (HR) monitoring to determine TL, time spent in HR zones expressed as a percent of HRmax (HRZ1-Z5), calories expended per kilogram body mass (Kcal·kg), distance covered (DIS), sprints, average speed (SPDAVG), and distance covered in speed zones (DISZ1-Z5). During games, no significant differences were seen between men and women for TL, Kcal·kg, HRZ1-Z5, SPDAVG, DIS, DISZ1, DISZ3, and DISZ4. However, men accumulated a significantly greater number of sprints and DISZ5 (p < 0.05) during games, whereas women accumulated a greater DISZ2 (p < 0.05). During practice, no differences were observed for TL, DIS, sprints, Kcal·kg, DISZ2, DISZ3, HRZ1-Z5, but men exhibited higher SPDAVG, (p < 0.05), DISZ1 (p < 0.05), DISZ4 (p < 0.05), and DISZ5 (p < 0.05). The parallels in Kcal·kg, total DIS, HR, and TL indicate a similar relative workload between men and women. However, distance covered in higher speed zones was found to be greater in men than women across practice and games likely reflecting inherent sex differences in the ability to achieve those speeds. Monitoring techniques that track relative player workloads throughout practices and games may enhance player health and performance during the season. An individualized approach to tracking high-intensity running may improve workload prescriptions on a per player basis.
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Walker, AJ, McFadden, BA, Sanders, DJ, Bozzini, BN, Conway, SP, and Arent, SM. Early season hormonal and biochemical changes in Division I field hockey players: is fitness protective? J Strength Cond Res XX(X): 000-000, 2020-The purpose was to evaluate changes in hormonal and biochemical markers as a result of the accumulated stress of the initial 4-week training block in field hockey players. Women's Division I field hockey players (N = 22; Mage = 19.7 ± 1.1 years) performed testing before the start of preseason (A1) that included body composition (%BF), vertical jump, and V[Combining Dot Above]O2max. Blood draws were conducted at A1 to assess creatine kinase (CK), iron (Fe), hemoglobin (HGB), hematocrit (HCT), percent saturation (%sat), total cortisol (TCORT), free cortisol (FCORT), interleukin-6 (IL-6), sex hormone-binding globulin (SHBG), prolactin (PRL), vitamin D (vitD), and thyroxine (T3). Blood draws were repeated 4 weeks later (A2). Athletes were monitored during this training block, which included 2 weeks of preseason and the first 2 weeks of the season, using heart rate monitors to determine energy expenditure (Kcal) and training load. There were significant disruptions in TCORT, FCORT, T3, CK, Fe, and SHBG (p < 0.05) from A1 to A2. V[Combining Dot Above]O2max accounted for 31% (p < 0.05) of the variance in TCORT and %BF accounting for an additional 20.1% (p < 0.05). V[Combining Dot Above]O2max accounted for 32.7% (p < 0.05) of the variance in FCORT. %BF accounted for 48.9% (p < 0.05) of the variance in T3. Kcal was positively correlated with V[Combining Dot Above]O2max (p < 0.05) and negatively correlated with %BF (p < 0.05). Athletes with higher V[Combining Dot Above]O2max and lower %BF may be capable of a higher work output and therefore more likely to experience increased physiological disruptions during intense training. The high-volume nature of preseason and differences in athlete fitness capabilities require coaches to manage players at an individual level to maintain athlete readiness.
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Walker, AJ, McFadden, BA, Sanders, DJ, Rabideau, MM, Hofacker, ML, and Arent, SM. Biomarker response to a competitive season in Division I female soccer players. J Strength Cond Res XX(X): 000-000, 2019-The purpose of this study was to evaluate effects of training load (TL) on performance and biomarkers of health, performance, and recovery in Division I female soccer players throughout a competitive season. Participants (N = 25, Mage = 20 ± 1.1 years) were monitored before the start of preseason and every 4-weeks thereafter (T1-T5). A battery of performance tests was administered before the start of preseason (P1) and end-of-season (P2), including body composition (percent body fat [%BF], fat free mass [FFM], and fat mass), vertical jump (VJ), and V[Combining Dot Above]O2max. Blood draws were conducted at every time point (T1-T5) to assess free and total cortisol (CORTF and CORTT), prolactin (PRL), T3, IL-6, creatine kinase (CK), sex-hormone binding globulin, omega-3 (n-3FA), vitamin-D (Vit-D), iron (Fe), hematocrit (HcT), ferritin (Fer), percent saturation (%Sat), and total iron-binding capacity (TIBC). Daily exercise energy expenditure (EEE) and TL were determined. There were significant declines in V[Combining Dot Above]O2max, VJ, weight, and %BF from P1-P2 (p < 0.05) with no significant differences in FFM. Training load and EEE significantly decreased from T1-T3 (p < 0.05). Significant increases were seen in CORTT, CORTF, PRL, T3, IL-6, CK, and TIBC throughout the season (p < 0.05). Significant decreases were seen in n-3FA, Fe, Fer, %Sat, and Hct throughout the season (p < 0.05). Female athletes experience significant physiological changes following high TL and EEE associated with preseason and appear to be further exacerbated by the cumulative effects of the season. Unique insights provided by biomarkers enable athletes and coaches to be cognizant of the physiological changes that are occurring throughout the season.
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Objectives The influence of hormonal contraceptives (HC) on inflammation and body composition after high-intensity combined strength and endurance training was investigated. Design Active healthy women formed two training groups: HC users (HCU, n = 9) and those who had never used HC (NHC, n = 9). Training included two strength training sessions and two high-intensity interval training sessions per week for 10 weeks. Methods Before (PRE) and after (POST) the training intervention, high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1beta (IL-1β) concentrations were measured. Dual-energy X-ray absorptiometry was used to estimate fat mass (FM), abdominal fat mass (aFM), and lean mass (LM). Results Circulating concentrations of hs-CRP decreased significantly in the NHC from pre to post with −0.46 mg l−1 (95% CI: −0.78, −0.14, p = 0.009, ES = 0.434), whereas a significant increase was observed in HCU from pre to post with 0.89 mg l−1 (95% CI: 1.66, 0.12, p = 0.048, ES = 1.988) with a significant between-group difference (p = 0.015). In addition, hs-CRP concentration was significantly higher in HCU than in NHC after training (p = 0.036) at post. Lean mass increased significantly more in NHC than in HCU (p = 0.049). Conclusions High-intensity combined strength and endurance training can modify inflammation and body composition of women. The present study showed that inflammation, in terms of hs-CRP was higher post training in HCU than NHC, which may be associated with smaller gains in lean mass in response to training.
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Huggins, RA, Fortunati, AR, Curtis, RM, Looney, DP, West, CA, Lee, EC, Fragala, MS, Hall, ML, and Casa, DJ. Monitoring blood biomarkers and training load throughout a collegiate soccer season. J Strength Cond Res XX(X): 000-000, 2018-This observational study aimed to characterize the responses of a comprehensive panel of biomarkers, observed ranges, training load (TL) metrics, and performance throughout the collegiate soccer season (August-November). Biomarkers (n = 92) were collected before the start of pre-season (PS), in-season weeks (W)1, W4, W8, and W12 in NCAA Division I male soccer players (n = 20, mean ± SD; age = 21 ± 1 years, height = 180 ± 6 cm, body mass = 78.19 ± 6.3 kg, body fat = 12.0 ± 2.6%, V[Combining Dot Above]O2max 51.5 ± 5.1 ml·kg·min). Fitness tests were measured at PS, and W12 and TL was monitored daily. Changes in biomarkers and performance were calculated via separate repeated-measures analysis of variance. Despite similar fitness (p > 0.05), endocrine, muscle, inflammatory, and immune markers changed over time (p < 0.05). Total and free testosterone was lower in W1 vs. PS, whereas free cortisol remained unchanged at PS, W1, and W4 (>0.94 mg·dL). Oxygen transport and iron metabolism markers remained unchanged except for HCT (W1 vs. PS) and total iron binding capacity (W8-W12 vs. W1). Hepatic markers albumin, globulin, albumin:globulin, and total protein levels were elevated (p < 0.05) at W12 vs. W1, whereas aspartate aminotransferase and alanine aminotransferase levels were elevated at W1-W12 and W8-W12 vs. PS, respectively. Vitamin E, zinc, selenium, and calcium levels were elevated (p < 0.05) at W12 vs. W1, whereas Vitamin D was decreased (p < 0.05). Fatty acids and cardiovascular markers (omega-3 index, cholesterol:high-density lipoprotein [HDL], docosahexenoic acid, low-density lipoprotein [LDL], direct LDL, non-HDL, ApoB) were reduced at W1 vs. PS (p ≤ 0.05). Immune, lipid, and muscle damage biomarkers were frequently outside clinical reference ranges. Routine biomarker monitoring revealed subclinical and clinical changes, suggesting soccer-specific reference ranges. Biomarker monitoring may augment positive adaptation and reduce injuries from stressors incurred during soccer.
Article
Purpose: To identify the period prevalence of hormonal contraceptive (HC) use and characterise the perceived side effects associated with the menstrual cycle and HC use. Methods: 430 elite female athletes completed a questionnaire to assess; the period prevalence of HC use, the reasons for initiation and discontinuation of HCs and the side effects experienced by HC and non-HC users. Descriptive statistics, between-group comparisons and associations between categorical variables were calculated. Results: 49.5% of athletes were currently using HCs and 69.8% had used HCs at some point. Combined oral contraceptives were most commonly used (68.1%), with 30.0% using progestin-only contraceptives (implant = 13.1%; injection = 3.7%; intrauterine system = 2.8%). Perceived negative side effects were more common with progestin-only HC use (39.1%) compared to combined HC use (17.8%; P = 0.001) and were most prevalent in implant users (53.6%; P = 0.004). HC users reported perceived positive side effects relating to the ability to predict and/or manipulate the timing, frequency and amount of menstrual bleeding. Non-HC users had a menstrual cycle length of 29 ± 5 d and 77.4% reported negative side effects during their menstrual cycle, primarily during days 1-2 of menstruation (81.6%). Conclusions: Approximately half of elite athletes used HCs and progestin-only contraceptive users reported greater incidences of negative side effects, especially with the implant. Due to the high inter-individual variability in reported side effects, athletes and practitioners should maintain an open dialogue to pursue the best interests of the athlete.
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In the practice of data analysis, there is a conceptual distinction between hypothesis testing, on the one hand, and estimation with quantified uncertainty on the other. Among frequentists in psychology, a shift of emphasis from hypothesis testing to estimation has been dubbed “the New Statistics” (Cumming 2014). A second conceptual distinction is between frequentist methods and Bayesian methods. Our main goal in this article is to explain how Bayesian methods achieve the goals of the New Statistics better than frequentist methods. The article reviews frequentist and Bayesian approaches to hypothesis testing and to estimation with confidence or credible intervals. The article also describes Bayesian approaches to meta-analysis, randomized controlled trials, and power analysis.
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This study examined the salivary testosterone (T) and cortisol (C) responses of elite women hockey players across 4 activities (light and heavy training, club and International competitions). The players formed an oral contraceptive (OC) group (n=10) and a Non-OC (n=19) group for analysis. The Non-OC group had higher T levels (by 31-52%) across all activities, whilst the OC group showed signs of reduced T and C reactivity when data were pooled. As a squad, positive T and C changes occurred with heavy training (45%, 46%), club competitions (62%, 80%) and International competitions (40%, 27%), respectively. Our results confirm that OC use lowers T levels in women athletes whilst reducing the T and C responses to training and competition activities within the sporting environment. Differences in the physical and/or psychological demands of the sporting activity could be contributing factors to the observed hormone responses. These factors require consideration when applying theoretical models in sport, with broader implications for women around exercising behaviours and stress physiology. Copyright © 2015. Published by Elsevier Inc.
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Objective: To determine whether basal Cortisol levels are elevated in exercise-associated amenorrhea. Design: Survey, with hormone levels measured weekly for 1 month and patients followed clinically for 6 months. Setting: Volunteers were recruited through media advertisements and fliers. Participants: Ninety-two women were enrolled; 71 (77%) completed the study. Subjects were grouped by menstrual and activity histories reported by a self-administered questionnaire. After 6 months, final groups were assigned: amenorrhea athletes, 19; eumenorrheic athletes, 35; a transition group of amenorrheic athletes who had resumed menses after entering the study, 7; and normal cyclic nonathletes, 10. Interventions: Four weekly resting blood samples (0800 to 1000 hours) were obtained and measured for Cortisol, estradiol, progesterone, and prolactin levels. Lumbar bone mineral density was measured by dual-photon densitometry. Measurements and Main Results: Mean (±SE) Cortisol levels were higher in amenorrheic athletes (585±33 nmol/L) than in eumenorrheic athletes (411±14 nmol/L), transition athletes (378±33 nmol/L), or nonathletic women (397±30 nmol/L) (P <0.01). Of nine women with abnormally high Cortisol levels (greater than 579 nmol/L), eight were amenorrheic athletes, and one was a eumenorrheic athlete. Bone mineral density was lower in amenorrheic athletes than in the other three groups (P <0.01). Conclusions: Increased glucocorticoid levels may be an etiologic factor in exercise-associated amenorrhea. High Cortisol levels could also contribute to decreased bone density. The failure of amenorrheic athletes with hypercortisolemia to regain menses within 6 months suggests that they are at risk for a prolonged acyclic state.
Article
Introduction Functional hypothalamic amenorrhea (FHA) is one of the most common causes of secondary amenorrhea. There are three types of FHA: weight loss-related, stress-related, and exercise-related amenorrhea. FHA results from the aberrations in pulsatile gonadotropin-releasing hormone (GnRH) secretion, which in turn causes impairment of the gonadotropins (follicle-stimulating hormone and luteinizing hormone). The final consequences are complex hormonal changes manifested by profound hypoestrogenism. Additionally, these patients present mild hypercortisolemia, low serum insulin levels, low insulin-like growth factor 1 (IGF-1) and low total triiodothyronine. Aim The aim of this work is to review the available data concerning the effects of FHA on different aspects of women’s health. Results Functional hypothalamic amenorrhea is related to profound impairment of reproductive functions including anovulation and infertility. Women’s health in this disorder is disturbed in several aspects including the skeletal system, cardiovascular system, and mental problems. Patients manifest a decrease in bone mass density, which is related to an increase in fracture risk. Therefore, osteopenia and osteoporosis are the main long-term complications of FHA. Cardiovascular complications include endothelial dysfunction and abnormal changes in the lipid profile. FHA patients present significantly higher depression and anxiety and also sexual problems compared to healthy subjects. Conclusions FHA patients should be carefully diagnosed and properly managed to prevent both short- and long-term medical consequences.
Article
Competitive female athletes restrict energy intake and increase exercise energy expenditure frequently resulting in ovarian suppression. The purpose of this study was to determine the impact of ovarian suppression and energy deficit on swimming performance (400m swim velocity). Menstrual status was determined by circulating estradiol (E2) and progesterone (P4) in ten junior elite female swimmers (15-17 yrs). The athletes were categorized as cyclic (CYC) or ovarian suppressed (OVS). They were evaluated every two weeks for metabolic hormones, bioenergetic parameters and sport performance over the 12-week season. CYC and OVS athletes were similar (p > 0.05) in age (CYC = 16.2 ± 1.8 yr; OVS = 17 ± 1.7 yr), BMI (CYC = 21 ± 0.4 kg/m; OVS = 25 ± 0.8 kg/m), and gynecological age (CYC = 2.6 ± 1.1 yr; OVS = 2.8 ± 1.5 yr). OVS had suppressed P4 (p < 0.001) and E2 (p = 0.002) across the season. Total triiodothyronine (TT3) and insulin-like growth factor (IGF-1) were lower in OVS (TT3: CYC = 1.6 ± 0.2 nmol/l; OVS = 1.4 ± 0.1 nmol/l p < 0.001; IGF-1: CYC = 243 ± 1 μg/ml; OVS = 214 ± 3 μg/ml p < 0.001) than CYC at Week 12. Energy intake (p < 0.001) and energy availability (p < 0.001) were significantly lower in OVS versus CYC. OVS exhibited a 9.8% decline in [INCREMENT]400m-swim velocity compared to an 8.2% improvement in CYC at Week 12. Ovarian steroids (P4 and E2), metabolic hormones (TT3 and IGF-1) and energy status markers (EA and EI) were highly correlated with sport performance. This study illustrates that when exercise training occurs in the presence of ovarian suppression with evidence for energy conservation (ie. reduced TT3), it is associated with poor sport performance. These data from junior elite female athletes support the need for dietary periodization to help optimize energy intake for appropriate training adaptation and maximal sport performance.
Chapter
Overview of normal menstrual cycleOverview of oral contraceptivesMechanism of action of oral contraceptivesImpact of oral contraceptive use on physical performanceSummaryReferences
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The purpose of this investigation was to assess the intrasession and intersession reliability of the Vertec, Just Jump System, and Myotest for measuring countermovement vertical jump (CMJ) height. Forty male and 39 female university students completed 3 maximal-effort CMJs during 2 testing sessions, which were separated by 24-48 hours. The height of the CMJ was measured from all 3 devices simultaneously. Systematic error, relative reliability, absolute reliability, and heteroscedasticity were assessed for each device. Systematic error across the 3 CMJ trials was observed within both sessions for males and females, and this was most frequently observed when the CMJ height was measured by the Vertec. No systematic error was discovered across the 2 testing sessions when the maximum CMJ heights from the 2 sessions were compared. In males, the Myotest demonstrated the best intrasession reliability (intraclass correlation coefficient [ICC] = 0.95; SEM = 1.5 cm; coefficient of variation [CV] = 3.3%) and intersession reliability (ICC = 0.88; SEM = 2.4 cm; CV = 5.3%; limits of agreement = -0.08 ± 4.06 cm). Similarly, in females, the Myotest demonstrated the best intrasession reliability (ICC = 0.91; SEM = 1.4 cm; CV = 4.5%) and intersession reliability (ICC = 0.92; SEM = 1.3 cm; CV = 4.1%; limits of agreement = 0.33 ± 3.53 cm). Additional analysis revealed that heteroscedasticity was present in the CMJ when measured from all 3 devices, indicating that better jumpers demonstrate greater fluctuations in CMJ scores across testing sessions. To attain reliable CMJ height measurements, practitioners are encouraged to familiarize athletes with the CMJ technique and then allow the athletes to complete numerous repetitions until performance plateaus, particularly if the Vertec is being used.
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This article reviews the interaction between the neuroendocrine and immune systems in response to exercise stress, considering gender differences. The body's response to exercise stress is a system-wide effort coordinated by the integration between the immune and the neuroendocrine systems. Although considered distinct systems, increasing evidence supports the close communication between them. Like any stressor, the body's response to exercise triggers a systematic series of neuroendocrine and immune events directed at bringing the system back to a state of homeostasis. Physical exercise presents a unique physiological stress where the neuroendocrine and immune systems contribute to accommodating the increase in physiological demands. These systems of the body also adapt to chronic overload, or exercise training. Such adaptations alleviate the magnitude of subsequent stress or minimize the exercise challenge to within homeostatic limits. This adaptive capacity of collaborating systems resembles the acquired, or adaptive, branch of the immune system, characterized by the memory capacity of the cells involved. Specific to the adaptive immune response, once a specific antigen is encountered, memory cells, or lymphocytes, mount a response that reduces the magnitude of the immune response to subsequent encounters of the same stress. In each case, the endocrine response to physical exercise and the adaptive branch of the immune system share the ability to adapt to a stressful encounter. Moreover, each of these systemic responses to stress is influenced by gender. In both the neuroendocrine responses to exercise and the adaptive (B lymphocyte) immune response, gender differences have been attributed to the 'protective' effects of estrogens. Thus, this review will create a paradigm to explain the neuroendocrine communication with leukocytes during exercise by reviewing (i) endocrine and immune interactions; (ii) endocrine and immune systems response to physiological stress; and (iii) gender differences (and the role of estrogen) in both endocrine response to physiological stress and adaptive immune response.
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Estrogens are female sex hormones that may also protect against peroxidative damage of membrane lipids and low density lipoproteins (LDL). Studies have reported that female rats have greater protection against free radical induced lipid peroxidation and muscle damage consequent to exercise than do male rats. It has been suggested that the lower susceptibility to exercise induced oxidative stress and muscle membrane disruption of female rats may be due primarily to the antioxidant and membrane stabilizing properties of estrogens. Studies on humans have indicated that the lower incidence of atherosclerosis seen in premenopausal females in comparison to males is due at least in part to the ability of estrogens to diminish LDL peroxidation. However, there is little evidence as to the potential of estrogens to protect human females from free radical induced peroxidation and muscle damage due to exercise. This paper reviews the evidence for membrane stabilization potential of estrogens and their possible mechanisms, and speculates as to the potential significance of this for human exercise.
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Modern hormonal contraceptives and intrauterine contraceptive devices have multiple biologic effects. Some of them may be the primary mechanism of contraceptive action, whereas others are secondary. For combined oral contraceptives and progestin-only methods, the main mechanisms are ovulation inhibition and changes in the cervical mucus that inhibit sperm penetration. The hormonal methods, particularly the low-dose progestin-only products and emergency contraceptive pills, have effects on the endometrium that, theoretically, could affect implantation. However, no scientific evidence indicates that prevention of implantation actually results from the use of these methods. Once pregnancy begins, none of these methods has an abortifacient action. The precise mechanism of intrauterine contraceptive devices is unclear. Current evidence indicates they exert their primary effect before fertilization, reducing the opportunity of sperm to fertilize an ovum.
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Strenuous exercise induces increased levels in a number of pro-inflammatory and anti-inflammatory cytokines, naturally occurring cytokine inhibitors and chemokines. Thus, increased plasma levels of TNF-alpha, IL-1, IL-6, IL-1 receptor antagonist, TNF receptors, IL-10, IL-8 and macrophage inflammatory protein-1 are found after strenuous exercise. The concentration of IL-6 increases up to 100-fold after a marathon race. The increase in IL-6 is tightly related to the duration of the exercise and there appears to be a logarithmic relationship. Furthermore, the increase in IL-6 is related to the intensity of exercise. Given the facts that IL-6, more than any other cytokine, is produced in large amounts in response to exercise, that IL-6 is produced locally in the skeletal muscle in response to exercise and that IL-6 is known to have growth factor abilities, it is likely that IL-6 plays a beneficial role and may be involved in mediating exercise-related metabolic changes.
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In a double-blind, controlled, randomized, four-arm, bicentric clinical study, the effect of four oral contraceptives (OCs) on various hormone parameters and serum-binding globulins was investigated. Four groups with 25 volunteers each (18-35 years of age) were treated for six cycles with monophasic combinations containing 21 tablets with either 30 microg ethinylestradiol (EE) + 2 mg dienogest (DNG) (30EE/DNG), 20 microg EE + 2 mg DNG (20EE/DNG), 10 microg EE + 2 mg estradiol valerate (EV) + 2 mg DNG (EE/EV/DNG) or 20 microg EE + 100 microg levonorgestrel (LNG) (EE/LNG). The study was completed by 91 subjects. Blood samples were taken after at least 12 h of fasting on Day 21-26 of the preceding control cycle and on Day 18-21 of the first, third and sixth treatment cycle. The serum concentrations of free testosterone were significantly decreased by about 40-60% in all four groups, while those of dehydroepiandrosterone sulfate (DHEAS) showed a time-dependent decrease during treatment. Except for EE/EV/DNG, which increased prolactin significantly during the third and sixth cycles, no change was observed with the EE-containing preparations. There was a significant increase in the levels of serum-binding globulins during treatment, which differed according to the composition of the OCs used. The rise in sex hormone-binding globulin (SHBG) was highest during intake of 30EE/DNG (+320%) and lowest with EE/LNG (+80%), while the effect of 20EE/DNG and EE/EV/DNG was similar (+270%). The thyroxine-binding globulin (TBG) levels increased significantly, by 50-60%, during treatment with the DNG-containing formulations, while the effect of EE/LNG was less significant (+30%). The rise in corticosteroid-binding globulin (CBG), which occurred in all groups, was most pronounced in women treated with 30EE/DNG (+90%) and least with EE/EV/DNG (+55%), indicating a strong influence of EE and no effect of the progestogen component. In all treatment groups, the frequency of intracyclic bleeding rose in the first treatment cycle and decreased thereafter. Cycle control was significantly better with 30EE/DNG or EE/LNG than with 20EE/DNG or EE/EV/DNG. There was no significant change in blood pressure, body mass index or pulse rate throughout the study. In conclusion, the DNG-containing OCs caused a higher rise in SHBG and TBG levels than the LNG-containing preparation. The effects on CBG suggest a lesser hepatic effect of 2 mg EV as compared to 20 or 30 microg EE. In contrast to EE, the use of estradiol in OCs appeared to increase prolactin release, while the cycle control was better with the OC containing 30 microg EE.
Article
During the acute training response, peripheral cellular mechanisms are mainly metabolostatic to achieve energy supply. During prolonged training, glycogen deficiency occurs; this is associated with increased expression of local cytokines, and decreased insulin secretion and beta-adrenergic stimulation and lipolysis in adipose tissue which looses energy. This is indicated by decrease of adipocyte hormone leptin, which has inhibitory effects on excitatory hypothalamic neurons. Leptin, insulin, and cytokines such as interleukin 6 (IL-6) contribute to the metabolic error signal to the hypothalamus which result in decrease of hypothalamic release hormones and sympathoadrenergic stimulation. Thyroid stimulating hormone (TSH) is correlated to the metabolic hormones leptin and insulin, and may be used as indicator of metabolic control. Because the hypothalamus integrates various error signals (metabolic, hormonal, sensory afferents, and central stimuli), the pituitary's releasing hormones represent the functional status of an athlete. Long-term overtraining will lead to downregulation of hypothalamic hormonal and sympathoadrenergic responses, catabolism, and fatigue. These changes contribute to myopathy with predominant expression of slow muscle fiber type and inadequacy in performance. Thyroid hormones are closely involved in the training response and metabolic control.
Article
In a double-blind. controlled, randomized, four-arm, bicentric clinical study, the effect of four oral contraceptives (OCs) on thyroid hormone parameters, cortisol, aldosterone, endothelin-I and angiotensin 11 was investigated. Four groups composed of 25 volunteers each (ages between 18 and 35 years) were treated for six cycles with monophasic combinations containing 21 tablets with either 30 mug ethinylestradiol (EE) + 2 mg dienogest (DNG) (30EE/DNG), 20 mug EE + 2 mg DNG (20EE/DNG), 10 mug EE + 2 mg estradiol valerate (EV) + 2 mg DNG (EE/EV/DNG) or 20 mug EE + 100 mug levonorgestrel (LNG) (EE/LNG). The study was completed by 91 subjects. Blood samples were taken by venipuncture after at least 12 h fasting on Day 21-26 of the control cycle and on Day 18-21 of the first, third and sixth treatment cycle. There was a significant increase in triiodothyronine (T3) and thyroxine (T4) by 20-40% in all treatment cycles, while thyroid-stimulating hormone was significantly increased only with EE/EV/DNG. Treatment with the DNG-containing OCs caused no change in free T4 (FT4) and a transitory reduction in free T3 (FT3) levels during the first cycle. During intake of EE/LNG, FT4 rose slightly, while FT3 was not altered. The pronounced rise in the serum concentrations of cortisol appeared to be related to the EE dose. During the first three cycles of treatment, no effect on angiotensin H levels was observed, while in the sixth cycle a significant decrease was measured in all treatment groups. The four OCs did not influence the serum concentrations of endothelin-I and no consistent effects were found concerning those of aldosterone. The results suggest that the three DNG-containing and the LNG-containing low-dose OCs may increase T3. T4 and cortisol due to an elevated binding to serum globulins, while the free proportion of the hormones is not or only slightly changed. Therefore, these OCs have only minor effects on thyroid function, adrenal and blood pressure serum parameters.
Article
Numerous factors influence the increased health risks of seamen. This study investigated sleep (by actigraphy) and the adaptation of the internal clock in watch-keeping crew compared to day workers, as possible contributory factors. Fourteen watch keepers, 4 h on, 8 h off (0800-1200/2000-2400 h, 1200-1600/2400-0400 h, 1600-2000/0400-0800 h) (fixed schedule, n = 6; rotating by delay weekly, n = 8), and 12 day workers participated during a voyage from the United Kingdom to Antarctica. They kept daily sleep diaries and wore wrist monitors for continuous recording of activity. Sleep parameters were derived from activity using the manufacturer's software and analyzed by repeated-measures ANOVA using SAS 8.2. Sequential urine samples were collected for 48 h weekly for 6-sulphatoxymelatonin measurement as an index of circadian rhythm timing. Individuals working watches of 1200-1600/2400-0400 h and 1600-2000/0400-0800 h had 2 sleeps daily, analyzed separately as main sleep (longest) and 2nd sleep. Main sleep duration was shorter in watch keepers than in day workers (p < 0.0001). Objective sleep quality was significantly compromised in rotaters compared to both day workers and fixed watch keepers, the most striking comparisons being sleep efficiency (percentage desired sleep time spent sleeping) main sleep (p < 0.0001) and sleep fragmentation (an index of restlessness) main sleep (p < 0.0001). The 2nd sleep was substantially less efficient than was the main sleep (p < 0.0001) for all watch keepers. There were few significant differences in sleep between the different watches in rotating watch keepers. Circadian timing remained constant in day workers. Timing of the 6-sulphatoxymelatonin rhythm was later for the watch of 1200-1600/2400-0400 h than for all others (1200-1600/2400-0400 h, 5.90 +/- 0.85 h; 1600-2000/0400-0800 h, 1.5 +/- 0.64 h; 0800-1200/ 2000-2400 h, 2.72 +/- 0.76 h; days, 2.09 +/- 0.68 h [decimal hours, mean +/- SEM]: ANOVA, p < 0.01). This study identifies weekly changes in watch time as a cause of poor sleep in watch keepers. The most likely mechanism is the inability of the internal clock to adapt rapidly to abrupt changes in schedule.
Article
It is now estimated that the prevalence of oral contraceptive use in athletic women matches that of women in the general population. The oral contraceptive pill (OCP) reduces cycle-length variability and provides a consistent 28-day cycle by controlling concentrations of endogenous sex hormones. The OCP is administered in three different forms that differ widely in chemical constitution and concomitant effects on the human body. As fluctuation in sex steroids are believed to be a possible causal factor in performance and exercise capacity, it is imperative to understand the effect of administering the various types of OCP on women. However, the research into oral contraceptives and exercise performance is not consistent. The type of OCP administered (monophasic, biphasic or triphasic), as well as the type and dose of estrogen and progestogen within, will have varying effects on exercise. To date, research in the area of oral contraceptives and exercise capacity is sparse and much has been plagued by poor research design, methodology and small sample size. It is clear from the research to date that more randomised clinical trials are urgently required to assess the array of OCP formulations currently available to women and their concomitant effect on health and exercise capacity. Therefore, the purpose of this article is to critically appraise the literature to date and to provide a current review of the physiological scientific knowledge base in relation to the OCP and exercise performance. In addition, methodological control, design and conduct will be considered with future areas of research highlighted.