Estimated energy expenditures and energy intakes of international female rugby sevens players in five days of a training camp and competition preparation

To understand the energy balance of international female rugby sevens (R7s) players in applied environments, this study estimated the energy intakes (EI) and total daily estimated energy expenditures (TDEE) during a five-day training camp (TRAIN) and phase of competition preparation (COMP) of equal duration. Tri-axial accelerometer devices were worn throughout both scenarios to estimate TDEE, whereas EI was estimated via self-reported food diaries. Energy deficits of −47% (TDEETRAIN: 14.6 ± 1.6 MJ·day−1, EITRAIN: 7.7 ± 0.9 MJ·day−1, p ≤ 0.001, d = 5.1) and −50% (TDEECOMP: 15.5 ± 1.6 MJ·day−1, EICOMP: 7.7 ± 1.0 MJ·day−1, p ≤ 0.001, d = 5.7) were observed throughout TRAIN (n = 11; age: 25 ± 4 years, height: 170 ± 6 cm, weight: 71 ± 7 kg) and COMP (n = 8; age: 25 ± 3 years, height: 172 ± 5 cm, weight: 72 ± 6 kg), respectively. Carbohydrate intakes were below the lower range of sports nutrition recommendations in both TRAIN (−62%; 2.3 ± 0.3 g·kg−1 BM, p ≤ 0.001) and COMP (−60%; 2.4 ± 0.5 g·kg−1 BM, p ≤ 0.001). For protein (TRAIN: 1.7 ± 0.4 g·kg−1 BM, COMP: 1.5 ± 0.1 g·kg−1 BM), intakes met the lower range of recommendations. Fat intake exceeded recommendations of the percentage of total EI (COMP: 39 ± 5%). Accordingly, the dietary strategies of international female R7s players may warrant optimization, as carbohydrate and fat intakes were less than optimal when compared to current performance-based sports nutrition guidelines

Perspectives of the barriers and enablers to nutritional adherence in professional male academy football players

Background Nutritional intake is important for young football players; however, little is known about the factors that influence their nutritional adherence. Purpose The aim of this study was to investigate players’, sports nutritionists’,and coaches’ perspectives of the barriers and enablers to adhering to nutritional recommendations within a professional football club. Method Individual interviews, based on the Capability, Opportunity, Motivation – Behaviour (COM-B) model and Theoretical Domains Framework (TDF), were conducted with 13 players (18 ± 1.3 years), 12 sports nutritionists, and 10 coaches from 2, 12, and 10 professional football clubs, respectively. Thematic analysis was used to interpret the data. Results Seven key themes were generated relating to the players’ barriers and enablers to nutritional adherence: (1) Capability: (a) Nutritional Knowledge; (b) Cooking Skills; (2) Opportunity: (c) Training Venue Food Provision; (d) Nutritionist Accessibility and Approachability; (e) Living Status: (3) Motivation: (f) Performance Implications; and (g) Role Modelling. Conclusion Inadequate food provision within the training and home environment, and limited time with the sports nutritionist were key barriers to nutritional adherence in youth football players. Football clubs should allocate more time for sports nutritionists to deliver nutrition support and sports nutritionists should aim to control the players environment to support optimal nutritional intake

Oral but Not Topical Sodium Bicarbonate Improves Repeated Sprint Performance During Simulated Soccer Match Play Exercise in Collegiate Athletes

This study investigated the effect of oral and topical sodium bicarbonate (SB) on soccer-specific performance during simulated soccer exercise. In a block randomized, double-blind, crossover design, ten collegiate male soccer players (stature: 181.7 ± 3.2 cm, body mass: 81.7 ± 10.5 kg) performed soccer-specific performance tests (countermovement jumps, Illinois agility, 8 x 25 m repeated sprints) throughout a 90 min soccer-specific aerobic field test (SAFT90) following 0.3 g/kg body mass (BM) SB in capsules (SB-ORAL), 0.9036 g/kg BM PR Lotion (SB-LOTION) or placebo capsules and lotion (PLA). Soccer-specific performance tests were conducted pre-SAFT90, during half-time and post-SAFT90. Blood samples were analyzed for acid-base balance (pH; bicarbonate, HCO3-) and strong ions (sodium, Na+; potassium, K+). Average sprint times were quicker for SB-ORAL than PLA during half-time (3.7%; p = .049; g = .57) and post-SAFT90 (4.9%; p = .041; g = .66). SB-ORAL increased pH and HCO3- pre-warm-up and during half-time (p < .05), and lowered K+ during half-time (p = .035) compared with PLA. SB-LOTION increased pH (p = .019) and lowered K+ (p = .012) during half-time compared with PLA. SB-LOTION increased Na+ post-exercise compared with PLA (p = .008). Repeated sprint times during simulated soccer exercise improved for SB-ORAL, which might have been mechanistically underpinned by elevated blood buffering capacity and greater regulation of strong ion concentration. Consuming SB in capsules is a more effective strategy than topical SB application for improving blood buffering capacity and repeated sprint performance throughout competitive soccer matches

Enhancing Exercise Performance and Recovery Through Sodium Bicarbonate Supplementation: Introducing the Ingestion Recovery Framework

Sodium bicarbonate (SB) supplementation is an ergogenic strategy for athletes competing in high-intensity exercise, but the efficacy of SB for accelerating recovery from exercise and thus improving performance during repeated bouts of exercise is not fully understood. In a similar fashion to using SB as a pre-exercise buffer, it is possible accelerated restoration of blood pH and bicarbonate following an exercise bout mechanistically underpins the use of SB as a recovery aid. Physiological mechanisms contributing to beneficial effects for SB during repeated bout exercise could be more far-reaching however, as alterations in strong ion difference (SID) and attenuated cellular stress response might also contribute to accelerated recovery from exercise. From inspection of existing literature, ingestion of 0.3 g kg−1 body mass SB ~60–90 min pre-exercise seems to be the most common dosage strategy, but there is evidence emerging for the potential application of post-exercise supplementation timing, gradual SB doses throughout a competition day, or even ingestion during exercise. Based on this review of literature, an SB ingestion recovery framework is proposed to guide athletes and practitioners on the use of SB to enhance performance for multiple bouts of exercise

Effect of bilberry juice on indices of muscle damage and inflammation in runners completing a half-marathon: a randomised, placebo-controlled trial.

Background: Emerging evidence indicates that fruits rich in polyphenols may attenuate exercise-induced muscle damage and associated markers of inflammation and soreness. This study was conducted to determine whether bilberry juice (BJ), which is particularly rich in polyphenols, reduces markers of muscle damage in runners completing a half marathon. Methods: A total of 21 recreationally trained runners (age 30.9 ± 10.4 y; mass 71.6 ± 11.0 kg; M=16; F=5) were recruited to a single blind, randomised, placebo-controlled, parallel study. Participants were block randomised to consume 2 x 200 ml of BJ or energy-matched control drink (PLA) for 5 d before the Sheffield Half Marathon, on race day, and for 2 days post-race. Measurements of delayed onset muscle soreness (DOMS), muscle damage (creatine kinase; CK) and inflammation (c-reactive protein ; CRP) were taken at baseline, pre-race, post-race, 24 h post-race and 48 h post-race. The effect of treatment on outcome measures was analysed using magnitude-based inferences based on data from 19 participants; 2 participants were excluded from the analyses because they did not provide samples for all time points. Results: The half marathon caused elevations in DOMS, CRP and CK. BJ had a possibly harmful effect on DOMS from pre-race to immediately post-race (11.6%, 90% CI ± 14.7%), a likely harmful effect on CRP from pre-race to 24 h post-race (mean difference ES 0.56, 90% CI ± 0.72) and a possibly harmful effect on CRP from pre-race to 48 h post-race (ES 0.12, 90% CI ± 0.69). At other time points, the differences between the BJ and PLA groups in DOMS and CRP were unclear, possibly trivial or likely trivial. Differences in the changes in CK between BJ and PLA were unclear at every time point other than from baseline to pre-race, where BJ had a possibly harmful effect on reducing muscle damage (ES 0.23, 90% CI ± 0.57). Conclusion: Despite being a rich source of antioxidant and anti-inflammatory phytochemicals, BJ evoked small to moderate increases in exercise-induced DOMS and CRP. Further larger studies are required to confirm these unexpected preliminary results

Normative data on regional sweat-sodium concentrations of professional male team-sport athletes

Background: The purpose of this paper was to report normative data on regional sweat sweat-sodium concentrations of various professional male team-sport athletes, and to compare sweat-sodium concentrations among sports. Data to this effect would inform our understanding of athlete sodium requirements, thus allowing for the individualisation of sodium replacement strategies. Accordingly, data from 696 athletes (Soccer, n = 270; Rugby, n = 181; Baseball, n = 133; American Football, n = 60; Basketball, n = 52) were compiled for a retrospective analysis. Regional sweat-sodium concentrations were collected using the pilocarpine iontophoresis method, and compared to self-reported measures collected via questionnaire. Results: Sweat-sodium concentrations were significantly higher (p < 0.05) in American football (50.4 ± 15.3 mmol·L-1), baseball (54.0 ± 14.0 mmol·L-1), and basketball (48.3 ± 14.0 mmol·L-1) than either soccer (43.2 ± 12.0 mmol·L-1) or rugby (44.0 ± 12.1 mmol·L-1), but with no differences among the N.American or British sports. There were strong positive correlations between sweat-sodium concentrations and self-reported sodium losses in American football (rs = 0.962, p < 0.001), basketball (rs = 0.953, p < 0.001), rugby (rs = 0.813, p < 0.001), and soccer (rs = 0.748, p < 0.001). Conclusions: The normative data provided on sweat-sodium concentrations might assist sports science/medicine practitioners in generating bespoke hydration and electrolyte-replacement strategies to meet the sodium demands of professional team-sport athletes. Moreover, these novel data suggest that self-reported measures of sodium loss might serve as an effective surrogate in the absence of direct measures; i.e., those which are more expensive or non-readily available

Practical nutritional recovery strategies for elite soccer players when limited time separates repeated matches

Specific guidelines that aim to facilitate the recovery of soccer players from the demands of training and a congested fixture schedule are lacking; especially in relation to evidence-based nutritional recommendations. The importance of repeated high level performance and injury avoidance while addressing the challenges of fixture scheduling, travel to away venues, and training commitments requires a strategic and practically feasible method of implementing specific nutritional strategies. Here we present evidence-based guidelines regarding nutritional recovery strategies within the context of soccer. An emphasis is placed on providing practically applicable guidelines for facilitation of recovery when multiple matches are played within a short period of time (i.e. 48 h). Following match-play, the restoration of liver and muscle glycogen stores (via consumption of ~1.2 gkg-1h-1 of carbohydrate) and augmentation of protein synthesis (via ~40 g of protein) should be prioritised in the first 20 minutes of recovery. Daily intakes of 6-10 gkg-1 body mass of carbohydrate are recommended when limited time separates repeated matches while daily protein intakes of >1.5 gkg-1 body mass should be targeted; possibly in the form of multiple smaller feedings (e.g., 6 x 20-40 g). At least 150% of the body mass lost during exercise should be consumed within 1 h and electrolytes added such that fluid losses are ameliorated. Strategic use of protein, leucine, creatine, polyphenols and omega-3 supplements could also offer practical means of enhancing post-match recovery. Keywords: soccer, nutrition, recovery, polyphenols, omega-3, creatine, fixture, congestio

Case study: the use of smartphone application technology to improve dietary practices, nutrition knowledge and body composition of a female international rugby union player

Nutrition application (app) technology may offer a cost-effective and novel method of maintaining better communication between athletes and practitioners at times of the season when such interactions may be limited (i.e. periods separating live-in training camps). In contrast to clinical populations, limited research has profiled the use of nutrition app technology within athletic cohorts. With indices of nutrition knowledge, body composition and dietary intake of primary interest, this case study reports the effects of implementing nutrition app usage with a female international rugby union player (19 years old, 6 international U20s caps). Anthropometric data, a general nutrition knowledge questionnaire (GKNQ) and a 3-day food diary were collected before and after an 8-week in-season period that separated two consecutive training camps. Normal communication methods between camps were complemented by the use of app technology (MealLogger, New York) which allowed photo and text commentary interactions between the athlete and performance nutritionist. Daily energy intake increased (2029 kCal.d-1 to 2213 kCal.d-1), GKNQ scores improved (68 to 76; +11%) and body composition benefitted (8-site skinfold sum 133mm to 112mm) from the 8-week period that required the upload, and subsequent commentary on, 161 meal photographs (~2.8 meals a day). By means of comparison, such changes were not observed in a comparable control player who completed the 8 week programme but did not receive the additional support via nutrition app technology. In scenarios where athlete-practitioner communication may be limited, the use of a nutrition app may be of benefit to the performance nutritionist to increase nutrition knowledge and body composition in team sport players

Nutrition for Extreme Sports

It has been well established that sound nutrition can accelerate recovery, enhance adaptations to training and improve performance. Competing in extreme sports places stress on the body, and conducting activities in extreme environments can exacerbate the physiological stress on the competitor. The physiological and metabolic requirements of different extreme sports vary greatly; thus nutritional requirements across the various extreme sports are diverse. Typically, for extreme sports that are longer in duration such as mountaineering, adventure racing, ultra-endurance activities and expedition-type events, the energy demands are much greater, and thus competitors should plan their dietary needs in advance. An inadequate diet and poor fuelling strategies can impair performance and increase the risk of injury and illness during events. This chapter discussed the various requirements across sports depending on the desired goal. Evidence-based weight management is discussed, and practical guidelines are summarised for athletes who want to manipulate body composition. Nutritional challenges, such as eating during travel, hydration and extreme weather conditions and cooling are discussed as well as some practical guidelines that athletes can put into practice to overcome some of these issues. Certain nutritional supplements such as creatine and beta-alanine can be beneficial for enhancing performance is certain extreme sports that involve repetitive explosive movements. Carbohydrate supplements and dietary nitrates may be beneficial for endurance-based activities such as adventure racing, ironman triathlons and cross-country skiing. The strategic use of caffeine supplementation may be beneficial for most extreme sports and in particular for extreme sports that are characterised by very long distances where athletes often choose to go without sleep for a period of greater than 24 h; while competing in events such as expeditions, caffeine can be used by competitors to help them stay awake and enhance performance

Nutritional Considerations in High Performance Youth Soccer: A Systematic Review

Purpose As players in high performance youth soccer (HYPS) environments undergo large changes in growth and maturation throughout the course of their development, they require specific nutritional intakes if they are to meet these demands. The purpose of this review was to synthesise current nutritional research conducted within HYPS players. Methods A systematic approach, following PRISMA guidelines, was employed to capture all articles related to nutrition within HPYS using the databases MEDLINE and SPORTDiscus. Study quality and risk of bias were assessed using a Downs and Black instrument. Observational and intervention studies which investigated an element of nutritional status, knowledge, or intervention in academy aged players (U9 to U23s) within HPYS settings were included. Results Fifty-three articles qualified assessing: current nutritional intake and energy balance (n = 21); ergogenic aids/supplements (n = 13); hydration status (n = 6); the influence of Ramadan fasting (n = 4); Vitamin D status (n = 4); female HPYS players (n = 3); nutrition knowledge (n = 2). Outcomes demonstrate a large proportion of HPYS players exhibit insufficient energy and carbohydrate intake, and a lack sufficient periodisation of nutrition to account for varying training/match loads. Large variability in energy intake and expenditure exists between and within chronological age groups, indicating the potential impact on growth and maturation. Female HPYS data is lacking but indicates similar trends to male counterparts. Conclusion HYPS players do not currently meet their energy requirements however the impact of growth and maturation is not fully understood. Furthermore, within this demographic future research is required into the barriers and enablers of players achieving adequate energy intake