Search

This study compared criterion to minimally invasive, practical measures of core (T[subscript c]) and skin (T[subscript sk) temperature during 30 min of moderate-intensity cycle exercise in a heat chamber (35°C, 60% rH). T[subscript c] was monitored using a core temperature pill (T[subscript c](Pill))] and tympanic thermometer (T[subscript c(Tymp)) during rest, exercise, and recovery in 15 participants. T[subscript sk] was monitored using hard-wired skin thermistors attached to a data logger (T[subscript sk(T))] and a thermal imaging camera (T[subscript sk(IR))] in 11 participants. T[subscript c] measurement resulted in no significant difference (p > 0.05), a mean bias of 0.1°C, coefficient of variation (CV%) of 1.0%, and correlation of r = 0.74 between devices. T[subscript sk] measurement resulted in a significant difference (p = 0.01), a mean bias of 0.6°C, CV% of 2.3%, and correlation of r = 0.61 between devices. T[subscript c(Tymp)] demonstrated acceptable agreement with T[subscriptc(Pill)]; however, caution is advised when using T[subscript sk(IR)] to give accurate measures of T[subscript sk] during exercise.

Purpose: Although recommendations for effective heat acclimation (HA) strategies for many circumstances exist, best-practice HA protocols specific to elite female team-sport athletes are yet to be established. Therefore, the authors aimed to investigate the effectiveness and retention of a passive HA protocol integrated in a female Olympic rugby sevens team training program. Methods: Twelve elite female rugby sevens athletes undertook 10 days of passive HA across 2 training weeks. Tympanic temperature (TTymp), sweat loss, heart rate, and repeated 6-second cycling sprint performance were assessed using a sport-specific heat stress test Pre-HA, after 3 days (Mid-HA), after 10 days (Post-HA), and 15 days post-HA (Decay). Results: Compared with Pre-HA, submaximal TTymp was lower Mid-HA and Post-HA (both by −0.2 [0.7] °C; d ≥ 0.71), while resting TTymp was lower Post-HA (by −0.3 [0.2] °C; d = 0.81). There were no differences in TTymp at Decay compared with Pre-HA, nor were there any differences in heart rate or sweat loss at any time points. Mean peak 6-second power output improved Mid-HA and Post-HA (76 [36] W; 75 [34] W, respectively; d ≥ 0.45) compared with Pre-HA. The observed performance improvement persisted at Decay by 65 (45) W (d = 0.41). Conclusions: Ten days of passive HA can elicit some thermoregulatory and performance benefits when integrated into a training program in elite female team-sport athletes. However, such a protocol does not provide a sufficient thermal impulse for thermoregulatory adaptations to be retained after 15 days with no further heat stimulus. [ABSTRACT FROM AUTHOR]

PurposeHigher physical activity (PA) has been associated with greater attenuation of body fat gain and preservation of lean mass across the lifespan. These analyses aimed to determine relationships of change in PA to changes in fat and lean body mass in a longitudinal prospective study of postmenopausal women.MethodsAmong 11,491 women enrolled at three Women's Health Initiative clinical centers who were selected to undergo dual-energy x-ray absorptiometry, 8352 had baseline body composition measurements, with at least one repeated measure at years 1, 3, and 6. PA data were obtained by self-report at baseline and 3 and 6 yr of follow-up. Time-varying PA effect on change in lean and fat mass during the 6-yr study period for age groups (50-59 yr, 60-69 yr, and 70-79 yr) was estimated using mixed effects linear regression.ResultsBaseline PA and body composition differed significantly among the three age groups. The association of change in fat mass from baseline and time-varying PA differed across the three age groups (P = 0.0006). In women age 50-59 yr, gain in fat mass from baseline was attenuated with higher levels of PA. Women age 70-79 yr lost fat mass at all PA levels. In contrast, change in lean mass from baseline and time-varying PA did not differ by age group (P = 0.1935).ConclusionsThe association between PA and change in fat mass varies by age group, with younger, but not older, women benefiting from higher levels of aerobic PA. Higher levels of aerobic activity are not associated with changes in lean mass, which tends to decrease in older women regardless of activity level. Greater attention to resistance training exercises may be needed to prevent lean mass loss as women age.

Aim: To highlight energy availability status, resting metabolic rate measures, dietary protein intake, and testosterone concentration in 4 elite male track cycling athletes (mean [SD]: age: 20.8 [1.5] y, body mass: 76.3 [3.6] kg, height: 181.8 [2.9] cm). Method: A cross-sectional observation included measures of energy availability (energy intake minus exercise energy expenditure, divided by fat-free mass), resting metabolic rate from indirect calorimetry, dietary protein intake from food records, blood analysis to assess sex hormone status, and performance markers. Results: Midrange testosterone (16.9–19.8 nmol/L), lowered resting metabolic rate ratio (0.76–0.98), varied luteinizing hormone (4–10 U/L), and suboptimal energy availability (26–41 kcal/kg fat-free mass/d, range) were observed in the male track cyclists. Protein intakes ranged from 2.0 g to 2.8 g protein/kg/d. Conclusion: The current cohort may have within-day energy deficiency, putting them in a catabolic state. [ABSTRACT FROM AUTHOR]

The roles of 17β estradiol (E2) and progesterone (P4), the primary female sex hormones, are pivotal in regulating various aspects of metabolism. E2 influences food intake, energy expenditure, adipose tissue distribution, and insulin sensitivity across multiple tissues. Meanwhile, P4 impacts energy expenditure, electrolyte balance, amino acid oxidation, muscle protein synthesis, and glucose metabolism. The interactions between these hormones affect macronutrient utilization, both at rest and during exercise. Acknowledging the need to incorporate sex hormone perturbations in research, this paper explores the current landscape of study design and menstrual cycle tracking for female-specific sport research. It emphasizes the importance of standardization in terminology, hormone phases, reference values, and affordable hormone detection methods to advance our understanding of how the menstrual cycle influences female athletes. [ABSTRACT FROM AUTHOR]

Provincial academies represent an important bridge between amateur and professional level rugby union in New Zealand. Athletes are provided with professional-level coaching; however, limited direct nutrition support is available. Congested training schedules and the requirement to work or study due to a lack of financial support may present a challenge towards athletes meeting nutrition requirements. The aim of the study was to facilitate improvement in nutrient intake, body composition and subjective well-being in provincial academy athletes via the implementation of a nutrition-support protocol based around behaviour change techniques. Significant increases in total energy (pre: 2492 ± 762 kcal; post: 2614 ± 625 kcal), relative energy (pre: 24.4 ± 7.5 kcal·kg; 25.5 ± 6.0 kcal·kg), total protein (pre: 131.1 ± 41.8 g; 153.8 ± 37.1 g) and relative protein (pre: 1.3 ± 0.4 g·kg; post: 1.5 ± 0.3 g·kg) were observed. Furthermore, changes in subjective sleep quality, stress, mood and upper body soreness were observed following the intervention. No changes were observed in body composition, carbohydrate or fat intake. Significant variability in nutrition and body composition changes highlights the importance of applying an individualised approach to nutrition support provision in developmental athletes. Practitioners working within these environments should be aware of the challenges and influences contributing to athletes' nutrition choices and habits. [ABSTRACT FROM AUTHOR]

Low energy availability (LEA) is a complex health condition that most commonly affects female athletes. Research on LEA is weighted to quantitative approaches, and few studies have employed qualitative methods to understand the development of LEA. Current research fails to understand the complexity of LEA by largely operating within isolated research paradigms. This paper aims to demonstrate the value of integrating a mixed-methods research approach to understand the influence of sporting cultures on the physiological experiences of female athletes with LEA. The mixed-methods approach implemented the use of physiological (quantitative) and socio-psychological (qualitative) data obtained from elite female athletes in three sports: triathlons and running, (n = 11), rugby sevens (n = 9), and track cycling (n = 10). The physiological data consisted of energy availability, haematological analysis, bone health, and body composition. The socio-psychological data consisted of individual semi-structured interviews with topics covering nutrition, body image, the impact of the sporting environment, and experience with LEA. The interview data were thematically analysed. By bringing qualitative and quantitative data together, this paper illustrates the complex relationship between sporting culture and the physiology of LEA. First, endurance athletes categorised as having an LEA showed a positive correlation between the relative energy intake (EI) and serum ferritin, with the interviews revealing a focus on a low body weight and reducing the EI. Second, the interviews with the rugby players showed a strong but hierarchical team culture, with the experienced players monitoring and controlling the EI of novice players. Third, among the cyclists, the EI was reduced in those categorised as having an LEA, with the interviews revealing a coach–athlete power relationship impacting dietary behaviours. To conclude, this paper demonstrates how mixed methods are important for capturing how different sporting cultures impact athletes' socio-psychological and physiological experiences of LEA. [ABSTRACT FROM AUTHOR]

Dietary intake is an important consideration for rugby union ('rugby') players to ensure substrate provision for optimal performance and facilitate recovery. Within-day meal distribution is especially important for athletes, particularly those with congested schedules and multiple daily training sessions. In the present study, 10 provincial academy rugby players engaged in a holistic support protocol informed by behaviour-change techniques led by a full-time sports nutritionist. Dietary intake was estimated during a 4-week monitoring and 4-week intervention period using the remote food photography method on one high-volume training day (two training sessions) and two low-volume training days (≤1 training session) per week. Lean body mass did not change significantly in response to the intervention. Significant increases were observed for protein on both low-volume (breakfast, AM snack, evening snack) and high-volume (post-gym, AM snack, evening snack) training days. Carbohydrate intake post-intervention was significantly greater at the pre-gym eating occasion but lower at PM snack and dinner eating occasions on high-volume days. These data suggest that incorporating a holistic support protocol led by a sports nutritionist can influence within-day nutrient intake in rugby players; however, no change to lean body mass was observed, and the influence of these changes in nutrient intake on performance and recovery warrants further investigation. [ABSTRACT FROM AUTHOR]

This article explores the socio-cultural dimensions of elite sportswomen's experiences of low energy availability (LEA), focusing particularly on elite track cyclists. With a multidisciplinary research team (two sport scientists and a feminist sociologist), the project began with a suite of quantitative measures that identified five of eight women track cycling athletes categorized with LEA and three athletes categorized with sub-optimal energy availability. This was then followed by semi-structured interviews that revealed the athletes' complex relationships with body image, menstruation, and nutrition practices, and varied experiences of LEA. Bringing the qualitative data into dialogue with the previously collated physiological data, however, helped us acknowledge the silences and deflection strategies among those with more severe cases of LEA. Ultimately, this article offers original insights both into elite track cyclists' understandings of body image, menstruation, and nutrition as associated with LEA, and important reflections on the challenges of doing interviews with sportswomen on sensitive topics in high-performance sporting environments. [ABSTRACT FROM AUTHOR]

Most of the low energy availability (LEA) research has been conducted in female populations. The occurrence of LEA in male athletes is not well known, even with an understanding of the components involved in and contributing to LEA. Cycling is a major risk factor for LEA due to inherent sports characteristics: low impact, high energy demands, and a common perception that leanness is a performance advantage. The purpose of this review is to discuss the cycling-specific studies that have documented components of RED-S. The review demonstrates male cyclists (1) experience energy deficits daily, weekly and throughout a season; (2) exhibit lower bone mineral density at the spine compared to the hip, and low bone mineral density correlating with LEA and; (3) demonstrate downregulation of the endocrine system with elevated cortisol, reduced testosterone and insulin-like growth factor 1. The complexity of LEA is further explored by the socio-psychological contribution that may impact eating behaviours, and therefore increase the risk of developing LEA. Future research directions include applying multifaceted research methods to gain a greater understanding of this syndrome and the effect of LEA on male cyclists. [ABSTRACT FROM AUTHOR]

Abstract Background Although studies have investigated the effects of hydration on performance measures, few studies have investigated how the temperature of the ingested liquid affects performance and core temperature during an exercise session. The hypothesis of the present study was that cold water would improve thermoregulation and performance as measured by bench repetitions to fatigue, broad jump for force and power and total time to exhaustion for cardiovascular fitness Methods Forty-five, physically fit, adult males (30.28 ± 5.4 yr, 1.77 ± 7.8 m, 83.46 ± 11.5 kg; 13.7 ± 4.8 %BF; 49.8 ± 6.3 ml/kg/min V02) completed two 60-minute exercise sessions. Subjects consumed either COLD (4°C) or room temperature (RT) water (22°C) in randomized order. Core temperature was measured every 15 minutes throughout each trial using a digestible thermometer. Three performance tests were performed upon completion of the exercise session: bench press to fatigue, standing broad jump, and bicycle time to exhaustion Results Although both groups significantly increased their core temperature (p Conclusion Drinking cold water can significantly mediate and delay the increase in core body temperature during an exercise session in a moderate climate with euhydrated subjects. The ingestion of COLD improved performance for 49% and 51% of the participants in the broad jump and TTE performance tests respectively, but did not reach statistical significance. Moreover, although minimal, subjects experienced a decrease in performance on the bench press during the COLD.

Background: Muscle adaptations are potentially enhanced through resistance training in elevated environmental temperatures (>30°C) due to upregulated anabolic hormonal responses. Method: Eighteen professional rugby union athletes performed a 3-week resistance training intervention where they were randomly allocated into 2 groups: HEAT (n = 8) with all lower-body training sessions performed in an environmental chamber set at 35°C and 37% relative humidity, or CON (n = 10) where identical training was performed under temperate conditions (21°C and 45%). Pre- and post-training tests included measures of strength, power, endurance, speed and body mass. Results:Small effect sizes were found in favour of HEAT for the back squat (g = 0.25) and bench press strength (g = 0.22). All other measures were associated with trivial or unclear effects. A significant group × time interaction was found for body mass, associated with a trivial effect size (g = 0.18, HEAT +1.5 kg; CON −0.8 kg). Discussion: Lower body resistance training in the heat led to small improvements in lower and upper body strength compared to the identical training program performed in temperate conditions. This observation is suggestive of a priming or potentiating effect of prior training in the heat. [ABSTRACT FROM AUTHOR]

International Journal of Exercise Science 12(2): 886-897, 2019. The aim of the current study was to; 1) assess the test-retest reliability of an indirect calorimetry analyzer (Parvo Medics TrueOne), and 2) compare measured RMR with three RMR-predictive (pRMR) equations in female athletes. In part one, 12 recreationallyexercising women (mean ± SD; age 27.5 ± 12.3 y) performed two RMR assessments, on separate days, utilising the Parvo Medics TrueOne analyser. In part two, 25 recreationally-exercising women to sub-elite athletes (mean ± SD; age 30.1 ± 10.2 y) underwent an RMR assessment using the Parvo Medics TrueOne analyser, which was compared to three calculated pRMR equations (Harris-Benedict (H-B), Mifflin-St Jeor (M), World Health Organisation (WHO)). eTest-retest reliability for the TrueOne analyser was deemed acceptable (CV = 5.3%, ICC = 0.92). The validity of pRMR when compared to measured RMR showed low levels of agreement in all 3 predictive equations (M: CV = 21.4%, TEE = 269 kcal.day-1, r = 0.16, WHO: CV = 21.5%, TEE = 270 kcal.day-1, r = 0.13 H-B: CV = 21.6%, TEE = 270 kcal.day-1, r = 0.13). The Parvo Medics TrueOne analyser is a reliable tool for measuring RMR. Caution should be taken when using pRMR equations in female athletes as they do not take into account the likely differences in fat free mass in these populations. [ABSTRACT FROM AUTHOR]

New Findings: What is the topic of this review? We review methodological considerations for the inclusion of women in sex and menstrual cycle phase comparison studies. What advances does it highlight? Improving the methodological design for studies exploring sex differences, menstrual cycle phase differences and/or endogenous versus exogenous female sex hormones will help to close the gap in our understanding of the effects of endogenous and exogenous hormones on exercise science and sports medicine outcomes. Abstract: In recent years, the increase in scientific literature exploring sex differences has been beneficial to both clinicians and allied health science professionals, although female athletes are still significantly under‐represented in sport and exercise science research. Women have faced exclusion throughout history though the complexities of sociocultural marginalization and biomedical disinterest in women's health. These complexities have contributed to challenges of studying women and examining sex differences. One underlying complexity to methodological design may be hormonal perturbations of the menstrual cycle. The biphasic responses of oestrogen and progesterone across the menstrual cycle significantly influence physiological responses, which contribute to exercise capacity and adaptation in women. Moreover, oral contraceptives add complexity through the introduction of varying concentrations of circulating exogenous oestrogen and progesterone, which may moderate physiological adaptations to exercise in a different manner to endogenous ovarian hormones. Thus, applied sport and exercise science research focusing on women remains limited, in part, by poor methodological design that does not define reproductive status. By highlighting specific differences between phases with regard to hormone perturbations and the systems that are affected, methodological inconsistencies can be reduced, thereby improving scientific design that will enable focused research on female athletes in sports science and evaluation of sex differences in responses to exercise. The aims of this review are to highlight the differences between endogenous and exogenous hormone profiles across a standard 28–32 day menstrual cycle, with the goal to improve methodological design for studies exploring sex differences, menstrual cycle phase differences and/or endogenous versus exogenous female sex hormones. [ABSTRACT FROM AUTHOR]

Copyright of Annales Kinesiologiae is the property of Annales Kinesiologiae and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article discusses a study which examined the relationship between body weight and risks of developing melanoma and nonmelanoma skin cancer (NMSC) in postmenopausal women. Particular focus is given to the use of Cox proportional hazard models and logistic regression in analyzing melanoma and NMSC risks. Prior skin cancer and sun exposure are cited as key predictors of skin cancer risk. The association between excess body weight and NMSC risk is also discussed.

The article discusses a study that evaluated the relationship of dietary fat intake with risks of women for nonmelanoma skin cancer (NMSC). Topics covered include assessment of women aged 50-79 years old in the postmenopausal stage with low-fat calorie intake of more fruits, vegetables and grains compared with the control group. Results showed that a low-fat diet intervention did not affect overall NMSC or melanoma incidence in women.

To determine whether there are sex differences in the prevalence of peripheral artery disease, we performed an observational study of 1014 men and 547 women, aged ≥ 40 years, referred for elective coronary angiography. Women were slightly older, more obese, had higher low-density lipoprotein cholesterol (LDL-C) levels and systolic blood pressure (BP), and were more likely to be African American. Women had higher high-density lipoprotein cholesterol (HDL-C) levels, lower diastolic BP, and were less likely to smoke or to have a history of cardiovascular disease. Women had less prevalent (62% vs 81%) and less severe coronary artery disease (CAD) (p < 0.001 for both) by coronary angiography, but more prevalent peripheral artery disease (PAD) as determined by the ankle—brachial index (ABI) than men (23.6% versus 17.2%). Independent predictors of lower ABI were female sex, black race, older age, tobacco use, CAD, diabetes, and triglyceride level. In a full multivariable logistic regression model, women had a risk-adjusted odds ratio for PAD of 1.78 (95% CI 1.25—2.54) relative to men. Among patients referred for coronary angiography, women have less prevalent and less severe CAD, but more prevalent PAD, a sex difference that is not explained by traditional cardiovascular disease risk factors or CAD severity. Clinical Trial Registration—URL: http://clinicaltrials.gov. Unique identifier: NCT00380185 [ABSTRACT FROM AUTHOR]

This study was conducted to investigate effects of an acute sodium load on resting plasma volume (PV) and renal mechanisms across the menstrual cycle of endurance- trained women with natural (NAT) or oral contraceptive pill (OCP) controlled cycles. Twelve women were assigned to one of two groups, according to their usage status: 1) OCP [n = 6, 29 yr (SD 6), 59.4 kg (SD 3.2)1, or 2) NAT [n = 6, 24 yr (SD 5), 61.3 kg (SD 3.6)]. The sodium load was administered as a concentrated sodium chloride/citrate beverage (164 mmol Na+/1, 253 mosmol/kgH2O, 10 ml/kg body mass) during the last high-hormone week of the OCP cycle (OCPhigh) or late luteal phase of the NAT cycle (NAThigh) and during the low-hormone sugar pill week of OCP (OCPlow) or early follicular phase of the NAT cycle (NATlow). The beverage (~628 ml) was ingested in seven portions across 60 mm. Over the next 4 h, PV expanded more in the low-hormone phase for both groups (time-averaged change): OCPlow 6.1% (SD 1.1) and NATlow 5.4% (SD 1.2) vs. OCPhigh 3.9% (SD 0.9) and NAThigh 3.5% (SD 0.8) (P = 0.02). The arginine vasopressin increased less in the low-hormone phase [1.63 (SD 0.2) and 1.30 pg/ml (SD 0.2) vs. 1.82 (SD 0.3) and 1.57 pg/mI (SD 0.5), P = 0.0001], as did plasma aldosterone concentration (~64% lower, P = 0.0001). Thus PV increased more and renal hormone sensitivity was decreased in the low-hormone menstrual phase following sodium/fluid ingestion, irrespective of OCP usage. [ABSTRACT FROM AUTHOR]

This study was conducted during the high-hormone phase of both natural and oral contraceptive pill (OCP)-mediated menstrual cycles to determine whether preexercise ingestion of a concentrated sodium beverage would increase plasma volume (PV), reduce physiological strain, and aid endurance of moderately trained women cycling in warm conditions. Thirteen trained cyclists [peak O2 uptake 52 ml·kg-1·min-1 (SD 2), age 26 yr (SD 6), weight 60.8 kg (SD 5)] who were oral contraceptive users (n = 6) or not (n = 7) completed this double-blind, crossover experiment. Cyclists ingested a concentrated-sodium (High Nat: 164 mmol Na+/l) or low-sodium (Low Na+: 10 mmol Na+/l) beverage (10 ml/kg) before cycling to exhaustion at 70% Peak O2 uptake in warm conditions (32°C, 50% relative humidity, air velocity 4.5 m/s). Beverage (~628 ml) was ingested in seven portions across 60 min beginning 105 min before exercise, with no additional fluid given until the end of the trial. Trials were separated by one to two menstrual cycles. High Na+ increased PV (calculated from hematocrit and hemoglobin concentration) before exercise, whereas Low Na+ did not [-4.4 (SD 1.1) vs. -1.9% (SD 1.3); 95% confidence interval: for the difference 5.20, 6.92; P < 0.0001], and it involved greater time to exhaustion [98.8 (SD 25.6) vs. 78.7 (SD 24.6) min; 95% confidence interval: 13.3, 26.8; P < 0.0001]. Core temperature rose more quickly with Low Na+ [1.6°C/h (SD 0.2)] than High Na+ [1.2°C/h (SD 0.2); P = 0.041. Plasma [AVP], [Na+] concentration, and osmolality, and urine volume, [Na+], and osmolality decreased with sodium loading (P < 0.05) independent of pill usage. Thus preexercise ingestion of a concentrated sodium beverage increased PV, reduced thermoregulatory strain, and increased exercise capacity for women in the high-hormone phase of natural and oral contraceptive pill-mediated menstrual cycles, in warm conditions. [ABSTRACT FROM AUTHOR]

Sex differences exist from birth, yet are often under-reported in exercise and nutrition research. Often women are excluded or grouped with men, without menstrual cycle phase acknowledgement. The aim of this talk is to describe sex differences as they apply to performance parameters of thermoregulation, hydration/hyponatremia, and thirst. The perturbations of sex hormones across the menstrual cycle induce several metabolic, thermoregulatory, and neuroendocrine challenges, which may impact performance. Women, compared to men, have higher body surface area to body mass ratio, higher body fat mass, and higher density and number of sweat glands. Women also use a higher percentage of sweat glands while secreting less sweat. These facts may cause inherent differences in tolerance to heat between the sexes. Women are at greater risk for exercise-induced hyponatremia (low blood sodium concentration) and this risk has been attributed to their lower body weight and size, excess water ingestion, and estrogen-mediated inhibition of potassium transfer. Moreover, the greater levels of estradiol in plasma and tissue also play a role in increasing the risk of hyponatremia in women. The hormonal influences of sex hormones affect fluid dynamics by altering capillary permeability, vasomotor function, and the central set-point control of renal hormones and plasma osmolality. Elevations in plasma progesterone concentrations during the luteal phase inhibit aldosterone-dependent sodium reabsorption at the kidneys due to progesterone competing with aldosterone for the mineralocorticoid receptor. Moreover, progesterone is thermogenic, induce a core body temperature rise by 0.5'C; with concomitant resetting of cutaneous vasodilation and the osmotic set-point for thirst. [ABSTRACT FROM AUTHOR]

This study investigated the effects of an acute sodium load on resting plasma volume and renal mechanisms across the menstrual cycle of endurance-trained women with natural or oral contraceptive pill (OCP) mediated cycles. Twelve women were assigned to one of two groups according to their usage status: 1) oral contraceptive pill (OCP, n = 6, 29 y (SD 6), 59.4 kg (SD 3.2)), or 2) natural cycle (NAT, n = 6, 24 y (5), 61.3 kg (3.6)). The sodium load was administered as a concentrated sodium chloride/citrate beverage (164 mmol Na+-1, 253 mOsmkg H2O-1, 10 ml kg-1 BM) during the last high hormone week of the OCP cycle (HHocp) or late-luteal phase of natural cycle (LUTnat);during the low hormone sugar pill week of OCP (SUGocp) or early follicular phase of natural cycle (FOLnat). Beverage (∼628 ml) was ingested in 7 portions across 60 min. Over the next 4 h, plasma volume (PV) expanded more in the low-hormone phase for both groups: (time-averaged change) SUGocp 6.1 (SD 1.1) and FOLnat and 5.4% (1.2) vs. HHocp 3.9 (0.9) and LUTnat 3.5% (0.8), P = 0.02. AVP sensitivity to sodium loading was lower in this phase (1.63 (0.2) and 1.30 pg ml-1 (0.2) vs. 1.82 (0.3) and 1.57 pg ml-1 (0.5), P = 0.0001), as was plasma aldosterone (∼64% lower, P=0.0001). Thus, PV increased more and renal hormone sensitivity was decreased in the low-hormone menstrual phase following sodium/fluid ingestion, irrespective of OCP usage. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to examine the independent and joint associations of sitting time and physical activity with risk of incident cardiovascular disease (CVD). Background: Sedentary behavior is recognized as a distinct construct beyond lack of leisure-time physical activity, but limited data exist on the interrelationship between these 2 components of energy balance. Methods: Participants in the prospective Women’s Health Initiative Observational Study (n = 71,018), 50 to 79 years of age and free of CVD at baseline (1993 to 1998), provided information on sedentary behavior, defined as hours of sitting/day, and usual physical activity at baseline and during follow-up through September 2010. First CVD (coronary heart disease or stroke) events were centrally adjudicated. Results: Sitting ≥10 h/day compared with ≤5 h/day was associated with increased CVD risk (hazard ratio: 1.18, 95% confidence interval: 1.09 to 1.29) in multivariable models including physical activity. Low physical activity was also associated with higher CVD risk (p for trend < 0.001). When women were cross-classified by sitting time and physical activity (p for interaction = 0.94), CVD risk was highest in inactive women (≤1.7 metabolic equivalent task-h/week) who also reported ≥10 h/day of sitting. Results were similar for coronary heart disease and stroke when examined separately. Associations between prolonged sitting and risk of CVD were stronger in overweight versus normal weight women and women 70 years of age and older compared with younger women. Conclusions: Prolonged sitting time was associated with increased CVD risk, independent of leisure-time physical activity, in postmenopausal women without a history of CVD. A combination of low physical activity and prolonged sitting augments CVD risk. [Copyright &y& Elsevier]

Position Statement: The International Society of Sports Nutrition (ISSN) provides an objective and critical review of the use of a ketogenic diet in healthy exercising adults, with a focus on exercise performance and body composition. However, this review does not address the use of exogenous ketone supplements. The following points summarize the position of the ISSN., 1. A ketogenic diet induces a state of nutritional ketosis, which is generally defined as serum ketone levels above 0.5 mM. While many factors can impact what amount of daily carbohydrate intake will result in these levels, a broad guideline is a daily dietary carbohydrate intake of less than 50 grams per day., 2. Nutritional ketosis achieved through carbohydrate restriction and a high dietary fat intake is not intrinsically harmful and should not be confused with ketoacidosis, a life-threatening condition most commonly seen in clinical populations and metabolic dysregulation., 3. A ketogenic diet has largely neutral or detrimental effects on athletic performance compared to a diet higher in carbohydrates and lower in fat, despite achieving significantly elevated levels of fat oxidation during exercise (~1.5 g/min)., 4. The endurance effects of a ketogenic diet may be influenced by both training status and duration of the dietary intervention, but further research is necessary to elucidate these possibilities. All studies involving elite athletes showed a performance decrement from a ketogenic diet, all lasting six weeks or less. Of the two studies lasting more than six weeks, only one reported a statistically significant benefit of a ketogenic diet., 5. A ketogenic diet tends to have similar effects on maximal strength or strength gains from a resistance training program compared to a diet higher in carbohydrates. However, a minority of studies show superior effects of non-ketogenic comparators., 6. When compared to a diet higher in carbohydrates and lower in fat, a ketogenic diet may cause greater losses in body weight, fat mass, and fat-free mass, but may also heighten losses of lean tissue. However, this is likely due to differences in calorie and protein intake, as well as shifts in fluid balance., 7. There is insufficient evidence to determine if a ketogenic diet affects males and females differently. However, there is a strong mechanistic basis for sex differences to exist in response to a ketogenic diet.

Pre-sleep nutrition habits in elite female athletes have yet to be evaluated. A retrospective analysis was performed with 14 NCAA Division I female soccer players who wore a WHOOP, Inc. band - a wearable device that quantifies recovery by measuring sleep, activity, and heart rate metrics through actigraphy and photoplethysmography, respectively - 24 h a day for an entire competitive season to measure sleep and recovery. Pre-sleep food consumption data were collected via surveys every 3 days. Average pre-sleep nutritional intake (mean ± sd: kcals 330 ± 284; cho 46.2 ± 40.5 g; pro 7.6 ± 7.3 g; fat 12 ± 10.5 g) was recorded. Macronutrients and kcals were grouped into high and low categories based upon the 50 th percentile of the mean to compare the impact of a high versus low pre-sleep intake on sleep and recovery variables. Sleep duration ( p  = 0.10, 0.69, 0.16, 0.17) and sleep disturbances ( p  = 0.42, 0.65, 0.81, 0.81) were not affected by high versus low kcal, PRO, fat, CHO intake, respectively. Recovery ( p  = 0.81, 0.06, 0.81, 0.92), RHR ( p  = 0.84, 0.64, 0.26, 0.66), or HRV ( p  = 0.84, 0.70, 0.76, 0.93) were also not affected by high versus low kcal, PRO, fat, or CHO consumption, respectively. Consuming a small meal before bed may have no impact on sleep or recovery.

Based on a comprehensive review and critical analysis of the literature regarding the nutritional concerns of female athletes, conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society: 1. Female athletes have unique and unpredictable hormone profiles, which influence their physiology and nutritional needs across their lifespan. To understand how perturbations in these hormones affect the individual, we recommend that female athletes of reproductive age should track their hormonal status (natural, hormone driven) against training and recovery to determine their individual patterns and needs and peri and post-menopausal athletes should track against training and recovery metrics to determine the individuals' unique patterns. 2. The primary nutritional consideration for all athletes, and in particular, female athletes, should be achieving adequate energy intake to meet their energy requirements and to achieve an optimal energy availability (EA); with a focus on the timing of meals in relation to exercise to improve training adaptations, performance, and athlete health. 3. Significant sex differences and sex hormone influences on carbohydrate and lipid metabolism are apparent, therefore we recommend first ensuring athletes meet their carbohydrate needs across all phases of the menstrual cycle. Secondly, tailoring carbohydrate intake to hormonal status with an emphasis on greater carbohydrate intake and availability during the active pill weeks of oral contraceptive users and during the luteal phase of the menstrual cycle where there is a greater effect of sex hormone suppression on gluconogenesis output during exercise. 4. Based upon the limited research available, we recommend that pre-menopausal, eumenorrheic, and oral contraceptives using female athletes should aim to consume a source of high-quality protein as close to beginning and/or after completion of exercise as possible to reduce exercise-induced amino acid oxidative losses and initiate muscle protein remodeling and repair at a dose of 0.32-0.38 g·kg -1 . For eumenorrheic women, ingestion during the luteal phase should aim for the upper end of the range due to the catabolic actions of progesterone and greater need for amino acids. 5. Close to the beginning and/or after completion of exercise, peri- and post-menopausal athletes should aim for a bolus of high EAA-containing (~10 g) intact protein sources or supplements to overcome anabolic resistance. 6. Daily protein intake should fall within the mid- to upper ranges of current sport nutrition guidelines (1.4-2.2 g·kg -1 ·day -1 ) for women at all stages of menstrual function (pre-, peri-, post-menopausal, and contraceptive users) with protein doses evenly distributed, every 3-4 h, across the day. Eumenorrheic athletes in the luteal phase and peri/post-menopausal athletes, regardless of sport, should aim for the upper end of the range. 7. Female sex hormones affect fluid dynamics and electrolyte handling. A greater predisposition to hyponatremia occurs in times of elevated progesterone, and in menopausal women, who are slower to excrete water. Additionally, females have less absolute and relative fluid available to lose via sweating than males, making the physiological consequences of fluid loss more severe, particularly in the luteal phase. 8. Evidence for sex-specific supplementation is lacking due to the paucity of female-specific research and any differential effects in females. Caffeine, iron, and creatine have the most evidence for use in females. Both iron and creatine are highly efficacious for female athletes. Creatine supplementation of 3 to 5 g per day is recommended for the mechanistic support of creatine supplementation with regard to muscle protein kinetics, growth factors, satellite cells, myogenic transcription factors, glycogen and calcium regulation, oxidative stress, and inflammation. Post-menopausal females benefit from bone health, mental health, and skeletal muscle size and function when consuming higher doses of creatine (0.3 g·kg -1 ·d -1 ). 9. To foster and promote high-quality research investigations involving female athletes, researchers are first encouraged to stop excluding females unless the primary endpoints are directly influenced by sex-specific mechanisms. In all investigative scenarios, researchers across the globe are encouraged to inquire and report upon more detailed information surrounding the athlete's hormonal status, including menstrual status (days since menses, length of period, duration of cycle, etc.) and/or hormonal contraceptive details and/or menopausal status.

Athlete health and wellbeing requires a holistic, multidimensional approach to understanding, supporting, and treating individual athletes. Building more supportive, inclusive, and equitable environments for the health and wellbeing of women and gender expansive people further requires gender-responsive approaches that promote broader cultural change. Feminist sport and exercise medicine practitioners, sports scientists, and social science researchers are increasingly coming together in their efforts to do this work. However, working across disciplines inevitably includes an array of ontological, epistemological, and political challenges. In this paper, we offer a curated 'dialogue' with a group of feminist scholars engaged in research and practice across disciplines, bringing them together to discuss some of the most pressing gendered issues in sport today (i.e., ACL injury, concussion, menstruation in sport, mental health, gender categories). In so doing, we amplify the voices of those working (empirically and clinically) at the disciplinary intersections of gender, sport and health, and learn about some of the current and future possibilities for transdisciplinary innovations and strategies for building (responsiveness to) cultural change., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Thorpe, Bekker, Fullagar, Mkumbuzi, Nimphius, Pape, Sims and Travers.)

Dietary intake is an important consideration for rugby union ('rugby') players to ensure substrate provision for optimal performance and facilitate recovery. Within-day meal distribution is especially important for athletes, particularly those with congested schedules and multiple daily training sessions. In the present study, 10 provincial academy rugby players engaged in a holistic support protocol informed by behaviour-change techniques led by a full-time sports nutritionist. Dietary intake was estimated during a 4-week monitoring and 4-week intervention period using the remote food photography method on one high-volume training day (two training sessions) and two low-volume training days (≤1 training session) per week. Lean body mass did not change significantly in response to the intervention. Significant increases were observed for protein on both low-volume (breakfast, AM snack, evening snack) and high-volume (post-gym, AM snack, evening snack) training days. Carbohydrate intake post-intervention was significantly greater at the pre-gym eating occasion but lower at PM snack and dinner eating occasions on high-volume days. These data suggest that incorporating a holistic support protocol led by a sports nutritionist can influence within-day nutrient intake in rugby players; however, no change to lean body mass was observed, and the influence of these changes in nutrient intake on performance and recovery warrants further investigation.

Health is a pre-requisite for optimal performance yet the parameters which govern health and performance of elite female athletes are little understood. The aim of this study was to quantify the health status of elite female athletes, and understand sociocultural factors influencing that status. The survey addressed demographic, health and athletic performance history, training load, contraceptive use, sport-specific appearance and performance pressures, and communication barriers. Three hundred and fifty-seven elite New Zealand female athletes were recruited to complete an on-line survey. Two hundred and nineteen athletes completed the survey. Oligomenorrhea/amenorrhea had been diagnosed in only 12% of athletes compared with 50% of athletes not on hormonal contraception who reported symptoms consistent with this diagnosis. Stress fractures and iron deficiency were common and associated with oligomenorrhoea/amenorrhea ( P = 0.002), disordered eating ( P = 0.009) or menorrhagia ( P = 0.026). Athletes involved in individual sports ( P = 0.047) and with higher training volumes ( P < 0.001) were more likely to report a medical illness. Seventy-three percent of athletes felt pressured by their sport to alter their physical appearance to conform to gender ideals with 15% engaging in disordered eating practices. Barriers to communicating female health issues included male coaches and support staff, and lack of quality information pertaining to health. Elite female athletes may fail to reach peak performance due to specific health issues and undiagnosed pathology. Sociocultural factors influence the effectiveness of support of female's health and performance. Organizational and cultural change is required if elite female athletes are to combine optimal health with best performance., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Heather, Thorpe, Ogilvie, Sims, Beable, Milsom, Schofield, Coleman and Hamilton.)

Background: Iron deficiency is a common deficiency disease worldwide with athletes at increased risk., Methods: A proposed new mechanism of exercise-induced iron deficiency in athletes involves the iron-regulatory hormone hepcidin, however, there is limited information on this amongst elite athletes. This study describes iron status in elite female rugby Sevens players., Results: Blood samples were collected at the start and mid-season and analyzed for serum iron, serum ferritin (SF), soluble transferring receptor (sTfR), high sensitivity C-reactive Protein (hsCRP) and hepcidin. Of the 17 players 18% were iron deficient (SF<30 µg/L) with 29-35% of players with sub-optimal iron stores at some point during the study (SF<45 µg/L). Serum hepcidin was strongly correlated with SF (r=0.61, P=0.0001)., Conclusions: Some elite female rugby Sevens players have sub-optimal iron stores over the course of a season.

Background: Hydration habits during training may differ depending on sports mode and individual characteristics. The aim of this study was to assess fluid intake behavior in a wide sample of Italian athletes during their regular training., Methods: Data on hydration habits during training were collected from a random sample of competitive athletes. Hydration strategies and personal characteristics were queried via questionnaire, including athletes' quantity and type of fluid ingested during a typical training bout, sport characteristics (e.g. mode and training duration), and whether their coach encouraged them to drink during trainings., Results: Three hundred and fifty-two competitive athletes participated to the study; two hundred eighty-nine athletes correctly completed all survey items (age: 8-63 years, median: 21±13 years). Athletes were involved in international (3.1%), national (34.1%) and regional (44.9%) competitions. Median fluid intakes during training were 0.25 L/h; 150 athletes reported fluid intake below the median, whilst 23 athletes (6.5% of total sample) reported fluid intake at or above currently published exercise hydration guidelines (NATA and ACSM). Binary logistic regression indicated that the number of pauses to drink (B=0.771, P=0.000), duration of a typical training bout (B=-2.237, P=0.000), and a coach's encouragement to drink (B=0.601, P=0.030) were each associated with fluid consumption above or below the median value., Conclusions: Athletes across all disciplines reported drinking less fluid during training than currently espoused in hydration guidelines. A coach's encouragement to drink, the number of pauses during training, and bout duration each influence total fluid volume consumed, regardless of competition level, sex or the age of an athlete.

Objective: The aim of this study was to determine whether a dietary intervention designed to reduce fat intake and increase intake of fruit, vegetables, and whole grains, and weight loss, reduces vasomotor symptoms (VMS; ie, hot flashes or night sweats) in postmenopausal women., Methods: We included 17,473 postmenopausal US women, ages 50 to 79 years, at baseline who participated in the Women's Health Initiative Dietary Modification trial and were not taking menopausal hormone therapy. Logistic regression was used to evaluate associations., Results: In multivariate-adjusted analyses, with simultaneous adjustment for the intervention and weight change, assignment to the dietary intervention versus the control arm was significantly (odds ratio [OR], 1.14; 95% CI, 1.01-1.28) related to a higher likelihood of symptom elimination among women with VMS at baseline. In addition, women with symptoms at baseline who lost 10 lb or more (OR, 1.23; 95% CI, 1.05-1.46) or lost 10% or more of their baseline body weight (OR, 1.56; 95% CI, 1.21-2.02) between baseline and year 1 were significantly more likely to eliminate VMS compared with those who maintained weight. Upon examining the joint effect of the dietary modification and weight loss, compared with women in the control arm who maintained weight, women who lost substantial weight (≥ 10%) as a part of the intervention (OR, 1.89; 95% CI, 1.39-2.57) but not as part of the control arm (OR, 1.40; 95% CI, 0.92-2.13) were significantly more likely to end VMS, although these two groups did not differ significantly from each other. Large weight loss (>22 lb), but not dietary changes, was related to the elimination of moderate/severe VMS., Conclusions: Weight loss as part of a healthy dietary modification may help eliminate VMS among postmenopausal women.