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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]

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]

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]

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]

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.