Caffeine improves the shooting performance and reaction time of first-person shooter esports players: a dose-response study.

Caffeine is recognized as one of the most effective dietary ergogenic aids in sports, yet its evidence-based effectiveness in esports is unclear. This study investigated the effects of two different doses of caffeine on the shooting performance and reaction time of 24 first-person shooter (FPS) esports players (22 men, 2 women; age = 22.29 ± 2.91 years). Participants completed three experimental trials in which they consumed either a water control (CON), a 1 mg·kg-1 BM (CAF1) or a 3 mg·kg-1 BM (CAF3) dose of caffeine. Performance measures (e.g., score, accuracy (%), hit rate (hits/sec), and shots fired) were assessed in a static clicking and reactive tracking style task on the KovaaK's FPS aim trainer. Reaction time was used to assess vigilance on the psychomotor vigilance test (PVT). Performance was measured at four time points in each trial: pre-treatment (PRE), 60 min (POST1), 80 min (POST2), and 100 min (POST3) post-treatment. Significant differences were identified using repeated-measures analysis of variances. Caffeine, irrespective of dose, significantly improved performance compared to CON for static clicking score and hit rate, reactive tracking accuracy, and reaction time on the PVT. Significant interactions between treatment and time were identified and post hoc analyses showed that compared to CON, CAF1 significantly improved static clicking score at POST1 and POST3, static clicking hit rate at POST1, reactive tracking accuracy at POST1, POST2, and POST3, and reaction time on the PVT at POST1 and POST2. Post hoc analysis also showed that compared to CON, CAF3 significantly improved static clicking score, reactive tracking accuracy, and reaction time on the PVT at all time points, in addition to static clicking hit rate at POST1 and POST3. In summary, caffeine supplementation enhances the shooting performance and reaction time of FPS esports players.

The Effect of Cannabidiol on Subjective Responses to Endurance Exercise: A Randomised Controlled Trial.

BACKGROUND: Exercise is known to improve health. However, it can be unpleasant, often inducing negative feelings, or 'affect'. Cannabidiol (CBD), a non-intoxicating constituent of the cannabis plant, has been reported to enhance the subjective experience of exercise; specifically, in trained individuals performing fixed-intensity endurance activity. Here, we investigated the effects of CBD on subjective responses to exercise under more ecologically valid conditions; namely, in recreationally active individuals performing self-paced endurance activity. METHODS: A randomised, double-blind, placebo-controlled, crossover trial was conducted at Griffith University between July 17 and August 28, 2023. Griffith University students studying sports nutrition were invited to take part, with eligible volunteers ≥ 18 years of age and able to perform endurance exercise. Participants ingested placebo or 150 mg CBD in two soft-gel capsules 90 min before completing a self-paced 25-lap (10 km) run around an outdoor athletics track (400 m, synthetic). The primary outcomes were affective valence during exercise, assessed on completion of laps 6, 12, 18 and 24 using the 'Feelings Scale', and positive and negative affect, assessed at baseline, pre-run and post-run using the 'Positive and Negative Affect Schedule'. Exercise enjoyment, motivation and self-efficacy, the core features of the 'runner's high' (i.e., euphoria, pain, anxiety, sedation), perceived exertion and run time were also assessed. RESULTS: Fifty-two participants were randomised and 51 were included in the final sample (n = 22 female; 22 [21-25] years). Exercise induced negative affect (i.e., at the time of undertaking) and increased pain. CBD did not counteract either response. In fact, CBD had no significant effects on any of the outcomes measured. In contrast, exercise, once completed, increased positive affect, and decreased negative affect and anxiety. CONCLUSIONS: CBD (150 mg, oral) does not appear to enhance the subjective experience of self-paced endurance exercise in recreationally active individuals. Nor, however, does it appear to compromise it. These findings suggest that CBD use is safe under exercise conditions and unlikely to impede physical activity participation. Our study also reaffirms the powerful mood-enhancing effects of exercise. TRIAL REGISTRATION: Registered with the Australian New Zealand Clinical Trials Registry ( www.anzctr.org.au ) on May 31, 2023 (Trial ID: ACTRN12623000593639).

KovaaK's aim trainer as a reliable metrics platform for assessing shooting proficiency in esports players: a pilot study.

Esports research lacks game-based metrics platforms appropriate for adequately capturing esports performance. The aim of this pilot study was to assess the reliability of the KovaaK's first-person shooter (FPS) aim trainer as a metrics platform for assessing shooting proficiency in esports players. Ten FPS esports players completed two identical experimental trials (T) separated by three to five days. Each trial included four rounds (R) of testing, evaluating four shooting tasks: Micro Flicking, Macro Flicking, Strafe Tracking, and Wall Peeking. Reliability of performance outcomes (e.g., accuracy, headshot accuracy, hits per second, and total shots hit) were assessed using the intraclass correlation coefficient (ICC) and their 95% confidence intervals (CI), and significant differences were identified using repeated-measures analysis of variance (RM-ANOVA). Results indicated excellent, or good to excellent reliability for all outcome variables with the ICC estimates ranging between 0.947-0.995, with lower and upper bound 95% CIs ranging between 0.876-0.988, and 0.984-0.999, respectively. Significant improvements were seen between experimental trials in the Macro Flicking task for accuracy (p = .005) and hits per second (p = .009) only. Significant interactions between trial and round were identified in the Micro Flicking task for accuracy (p = .006), with post hoc analysis showing accuracy was significantly higher in T1R1 compared to T2R1 (87.74 ± 3.13 vs. 85.99 ± 3.05, respectively, p = .02), and in T2R4 compared to T2R2 (87.99 ± 2.89 vs. 84.70 ± 4.25, respectively, p = .049). Significant interactions were also identified in the Strafe Tracking task for headshot accuracy (p = .002), with post hoc analysis showing headshot accuracy was significantly higher in T1R2 compared to T2R2 (78.48 ± 8.15 vs. 76.79 ± 12.16, respectively, p = .003), and in T1R2 compared to T1R1 (78.48 ± 8.15 vs. 73.68 ± 17.94, respectively, p = .023). In summary, this study demonstrates that KovaaK's provides a reliable metrics platform for assessing shooting proficiency in esports, however, some variability in performance was observed.

A review of factors influencing drinking behaviours in young Australian adults using a behavioural framework approach.

ISSUES: Young adults (aged 18-24 years) are more likely to binge drink than any other age group in Australia. These behaviours expose young adults to possible adverse events, with potential for acute harms. APPROACH: A behavioural framework (capability, opportunity, motivation-behaviour [COM-B model]) was used to explore factors that influence the drinking behaviours of young Australian adults. Potential studies were identified by searching four online data bases. Content pertaining to factors moderating young adults' alcohol consumption behaviours (either increasing or decreasing alcohol consumption) in an Australian population was extracted. Factors were then categorised/mapped into the six sub-components of the COM-B model. A narrative synthesis/discussion was subsequently undertaken. KEY FINDINGS: Factors increasing or reducing alcohol consumption behaviours were identified across all components of the COM-B model. Overall, alcohol consumption behaviours appear strongly influenced by physical and social opportunities, and young adults have reflective and automatic motivations (i.e., habitual processes, emotional responding and analytical decisional making that directs behaviour) to consume alcohol with purpose and/or reason. IMPLICATIONS AND CONCLUSION: The use of a behavioural framework (e.g., the COM-B model) facilitates an integrated understanding of factors influencing alcohol consumption behaviours. Future harm minimisation strategies need to consider the interrelated, contemporary factors underpinning a young adult's decision to consume alcohol within the context of modern Australian society.

The effect of contact/collision sport participation without concussion on neurometabolites: A systematic review and meta-analysis of magnetic resonance spectroscopy studies.

The aim of this study was to systematically review prior research investigating the effects of contact/collision sport participation on neurometabolite levels in the absence of concussion. Four online databases were searched to identify studies that measured neurometabolite levels in contact/collision sport athletes (without concussion) using proton (1 H) or phosphorus (31 P) magnetic resonance spectroscopy (MRS). All study designs were acceptable for inclusion. Meta-analytic procedures were used to quantify the effect of contact/collision sport participation on neurometabolite levels and explore the impact of specific moderating factors (where sufficient data were available). Narrative synthesis was used to describe outcomes that could not be meta-analysed. Nine observational studies involving 300 contact/collision sport athletes were identified. Six studies (providing 112 effect estimates) employed longitudinal (cohort) designs and three (that could not be meta-analysed) employed case-control designs. N-acetylaspartate (NAA; g = -0.331, p = 0.013) and total creatine (tCr; creatine + phosphocreatine; g = -0.524, p = 0.029), but not glutamate-glutamine (Glx), myo-inositol (mI) or total choline (tCho; choline-containing compounds; p's > 0.05), decreased between the pre-season and mid-/post-season period. Several moderators were statistically significant, including: sex (Glx: 6 female/23 male, g = -0.549, p = 0.013), sport played (Glx: 22 American football/4 association football [soccer], g = 0.724, p = 0.031), brain region (mI: 2 corpus callosum/9 motor cortex, g = -0.804, p = 0.015), and the MRS quantification approach (mI: 18 absolute/3 tCr-referenced, g = 0.619, p = 0.003; and tCho: 18 absolute/3 tCr-referenced, g = 0.554, p = 0.005). In case-control studies, contact/collision sport athletes had higher levels of mI, but not NAA or tCr compared to non-contact sport athletes and non-athlete controls. Overall, this review suggests that contact/collision sport participation has the potential to alter neurometabolites measured via 1 H MRS in the absence of concussion. However, further research employing more rigorous and consistent methodologies (e.g. interventional studies with consistent 1 H MRS pulse sequences and quantifications) is required to confirm and better understand the clinical relevance of observed effects.

Preparation procedures of food and beverage samples for oxygen bomb calorimetry: A scoping review and reporting checklist.

Standardised bomb calorimetry methods are essential to accurately quantify the gross energy within food and beverages, yet no accepted protocols exist. The objective of this review was to synthesise literature on food and beverage sample preparation methods used for conducting bomb calorimetry. This synthesis enhances our understanding of the extent to which methodological variances may currently affect estimates of the caloric values of dietary items. Five electronic databases were searched for peer reviewed literature on food and beverage energy measurement via bomb calorimetry. Data were extracted on seven identified methodological themes, including: (1) initial homogenisation, (2) sample dehydration, (3) post-dehydration homogenisation, (4) sample presentation, (5) sample weight, (6) sample frequency, and (7) equipment calibration. A tabular and narrative approach was used to synthesise the data. Studies that specifically explored the impact of any methodological variance on the energy derived from foods and/or beverages were also considered. In total, 71 documents describing food and beverage sample preparation techniques and processes used for bomb calorimetry were identified. Only 8% of studies described all seven identified sample preparation and calibration processes. The most frequent approaches used included: initial homogenisation - mixing or blending (n = 21); sample dehydration - freeze drying (n = 37); post-dehydration homogenisation - grinding (n = 24); sample presentation - pelletisation (n = 29); sample weight - 1g (n = 14); sample frequency - duplicate (n = 17); and equipment calibration - benzoic acid (n = 30). The majority of studies that have measured food and beverage energy via bomb calorimetry do not describe sample preparation and calibration methods in detail. The extent to which different sample preparation processes influence the energy derived from food and beverage items is yet to be fully elucidated. Use of a bomb calorimetry reporting checklist (described within) may assist with improving the methodological quality of bomb calorimetry studies.

The availability and promotion of low alcohol beverages in licensed venues: an environmental audit on the Gold Coast, Australia.

OBJECTIVES: Low-alcohol beverages (LABs) are becoming increasingly popular and more accepted in Australia. However, the extent to which these products are accessible in licensed venues remains unknown. This investigation aimed to explore the availability, visibility, advertising, and promotion of LAB products at licensed venues. STUDY TYPE: A cross-sectional environmental audit of licensed venues in four entertainment locations on the Gold Coast, Queensland. METHODS: An audit tool was developed. Licensed venues selected for auditing included bars, pubs, clubs, and nightclubs. Consent for conducting the audits was obtained from selected venues. Audits involved a walk-through of each venue's public areas and a review of their beverage menu to observe availability, visibility, advertising, and promotion of LAB products. RESULTS: A total of 58 venues were identified, with 32 (55%) providing written consent to audit. Overall, 18 venues (56%) offered patrons the opportunity to purchase LAB products. At bar service areas, LAB products were 'not visible' in 20 (63%) venues, and 'somewhat visible' in 12 (38%) venues. No bar service areas displayed LAB products with 'high visibility'. Of 29 beverage menus audited, 10 (34%) displayed LAB products, with varying levels of visibility. LAB-related advertising and/or promotion was not identified in any of the venues. CONCLUSIONS: LABs were available in approximately half the licensed venues audited; however, the visibility and promotion of these products were poor. There is capacity to improve access to and promote lower alcohol alternatives within licensed venues.

Effects of Different Sources of Low-Dose Caffeine on Mood/Arousal and Cognitive Performance.

In this study we investigated the effects of variously derived sources of low-dose caffeine on mood/arousal and cognitive performance. Twenty-two participants (15 men, 7 women; M age: 28.2, SD = 9.0 years) undertook five randomized, crossover trials in which they consumed either a water control (CON) or 80 mg of caffeine from one of four sources (coffee [COF], energy drink [END], capsule [CAP], and dissolvable mouth strip [STR]). We measured the participants' perceived efficacy of these varied caffeine sources pre-treatment; and we measured mood/arousal at pre-treatment, and again at 15 and 45 minutes post-treatment. We also measured choice reaction-time at 15 and 45 minutes post-treatment, and participants completed the psychomotor vigilance task (PVT) 45 minutes post-treatment. Caffeine increased participant ratings of alertness and decreased their ratings of tiredness irrespective of source (p's < .05), and all sources of caffeine decreased reaction time on the PVT (p's < .05), with ex-Gaussian distributional analysis localizing this to the tau-parameter, indicating lower variability. However, only the COF source was associated with improved 'overall mood' (p's < .05). Participants expected to perform better on the PVT with COF compared to CON, but there were no other significant associations between source expectancy and performance. In sum, a modest dose of caffeine, regardless of source, positively impacted mood/arousal and cognitive performance, and these effects did not appear to be influenced by expectations.

Patient and Staff Perceptions on Using Bioelectrical Impedance Analysis in an Outpatient Haemodialysis Setting: A Qualitative Descriptive Study.

Bioelectrical impedance analysis (BIA) is an objective hydration and body composition assessment method recommended for use in haemodialysis patients. Limited research exists on the acceptability and utility of BIA in clinical practice. This qualitative study explored patient and staff acceptability and perceived value of BIA in an outpatient haemodialysis setting at a tertiary public hospital in Queensland, Australia. Participants included five patients receiving outpatient haemodialysis and 12 multidisciplinary clinical staff providing care to these patients. Semi-structured interviews were employed and data were analysed thematically. Patients were satisfied with the BIA measurement process and most thought the BIA data would be useful for monitoring changes in their nutrition status. Clinical staff valued BIA data for improving fluid management, assessing nutrition status and supporting patient care. Staff recommended targeting BIA use to patient groups who would benefit the most to improve its uptake in the haemodialysis setting. Conclusions: BIA use in the outpatient haemodialysis setting is acceptable and provides valuable objective data to support health-related behaviour changes in patients and enhance clinical practice. Implementation of BIA should be tailored to the local context and staff should be supported in its use.

Effects of Acute Sleep Loss on Physical Performance: A Systematic and Meta-Analytical Review.

BACKGROUND: Sleep loss may influence subsequent physical performance. Quantifying the impact of sleep loss on physical performance is critical for individuals involved in athletic pursuits. DESIGN: Systematic review and meta-analysis. SEARCH AND INCLUSION: Studies were identified via the Web of Science, Scopus, and PsycINFO online databases. Investigations measuring exercise performance under 'control' (i.e., normal sleep, > 6 h in any 24 h period) and 'intervention' (i.e., sleep loss, ≤ 6 h sleep in any 24 h period) conditions were included. Performance tasks were classified into different exercise categories (anaerobic power, speed/power endurance, high-intensity interval exercise (HIIE), strength, endurance, strength-endurance, and skill). Multi-level random-effects meta-analyses and meta-regression analyses were conducted, including subgroup analyses to explore the influence of sleep-loss protocol (e.g., deprivation, restriction, early [delayed sleep onset] and late restriction [earlier than normal waking]), time of day the exercise task was performed (AM vs. PM) and body limb strength (upper vs. lower body). RESULTS: Overall, 227 outcome measures (anaerobic power: n = 58; speed/power endurance: n = 32; HIIE: n = 27; strength: n = 66; endurance: n = 22; strength-endurance: n = 9; skill: n = 13) derived from 69 publications were included. Results indicated a negative impact of sleep loss on the percentage change (%Δ) in exercise performance (n = 959 [89%] male; mean %Δ = - 7.56%, 95% CI - 11.9 to - 3.13, p = 0.001, I2 = 98.1%). Effects were significant for all exercise categories. Subgroup analyses indicated that the pattern of sleep loss (i.e., deprivation, early and late restriction) preceding exercise is an important factor, with consistent negative effects only observed with deprivation and late-restriction protocols. A significant positive relationship was observed between time awake prior to the exercise task and %Δ in performance for both deprivation and late-restriction protocols (~ 0.4% decrease for every hour awake prior to exercise). The negative effects of sleep loss on different exercise tasks performed in the PM were consistent, while tasks performed in the AM were largely unaffected. CONCLUSIONS: Sleep loss appears to have a negative impact on exercise performance. If sleep loss is anticipated and unavoidable, individuals should avoid situations that lead to experiencing deprivation or late restriction, and prioritise morning exercise in an effort to maintain performance.

Effects of Cannabidiol on Exercise Physiology and Bioenergetics: A Randomised Controlled Pilot Trial.

BACKGROUND: Cannabidiol (CBD) has demonstrated anti-inflammatory, analgesic, anxiolytic and neuroprotective effects that have the potential to benefit athletes. This pilot study investigated the effects of acute, oral CBD treatment on physiological and psychological responses to aerobic exercise to determine its practical utility within the sporting context. METHODS: On two occasions, nine endurance-trained males (mean ± SD V̇O2max: 57.4 ± 4.0 mL·min-1·kg-1) ran for 60 min at a fixed intensity (70% V̇O2max) (RUN 1) before completing an incremental run to exhaustion (RUN 2). Participants received CBD (300 mg; oral) or placebo 1.5 h before exercise in a randomised, double-blind design. Respiratory gases (V̇O2), respiratory exchange ratio (RER), heart rate (HR), blood glucose (BG) and lactate (BL) concentrations, and ratings of perceived exertion (RPE) and pleasure-displeasure were measured at three timepoints (T1-3) during RUN 1. V̇O2max, RERmax, HRmax and time to exhaustion (TTE) were recorded during RUN 2. Venous blood was drawn at Baseline, Pre- and Post-RUN 1, Post-RUN 2 and 1 h Post-RUN 2. Data were synthesised using Cohen's dz effect sizes and 85% confidence intervals (CIs). Effects were considered worthy of further investigation if the 85% CI included ± 0.5 but not zero. RESULTS: CBD appeared to increase V̇O2 (T2: + 38 ± 48 mL·min-1, dz: 0.25-1.35), ratings of pleasure (T1: + 0.7 ± 0.9, dz: 0.22-1.32; T2: + 0.8 ± 1.1, dz: 0.17-1.25) and BL (T2: + 3.3 ± 6.4 mmol·L-1, dz: > 0.00-1.03) during RUN 1 compared to placebo. No differences in HR, RPE, BG or RER were observed between treatments. CBD appeared to increase V̇O2max (+ 119 ± 206 mL·min-1, dz: 0.06-1.10) and RERmax (+ 0.04 ± 0.05 dz: 0.24-1.34) during RUN 2 compared to placebo. No differences in TTE or HRmax were observed between treatments. Exercise increased serum interleukin (IL)-6, IL-1ß, tumour necrosis factor-α, lipopolysaccharide and myoglobin concentrations (i.e. Baseline vs. Post-RUN 1, Post-RUN 2 and/or 1-h Post-RUN 2, p's < 0.05). However, the changes were small, making it difficult to reliably evaluate the effect of CBD, where an effect appeared to be present. Plasma concentrations of the endogenous cannabinoid, anandamide (AEA), increased Post-RUN 1 and Post-RUN 2, relative to Baseline and Pre-RUN 1 (p's < 0.05). CBD appeared to reduce AEA concentrations Post-RUN 2, compared to placebo (- 0.95 ± 0.64 pmol·mL-1, dz: - 2.19, - 0.79). CONCLUSION: CBD appears to alter some key physiological and psychological responses to aerobic exercise without impairing performance. Larger studies are required to confirm and better understand these preliminary findings. Trial Registration This investigation was approved by the Sydney Local Health District's Human Research Ethics Committee (2020/ETH00226) and registered with the Australia and New Zealand Clinical Trials Registry (ACTRN12620000941965).

Effectiveness of self-managed home and community exercise interventions in improving physical activity, body adiposity and related health indices in adults living with HIV: a protocol for a systematic review.

BACKGROUND AND OBJECTIVES: Disorders of adipose tissue distribution in people living with the human immunodeficiency virus (HIV) have been associated with significant metabolic derangements that increase their risk of cardiometabolic and other chronic diseases. Systematic reviews focusing on supervised laboratory-based exercise interventions demonstrate that these interventions improve adipose tissue distribution and related health outcomes in people living with HIV (PLWH). However, there is a need to examine the effectiveness of more pragmatic home or community exercise programmes. The aim of this review will be to synthesize existing evidence on the effectiveness of self-managed home or community exercise interventions to improve physical activity levels, adipose tissue distribution and associated health indices in PLWH. METHODS: This review will encompass interventional studies that evaluate the effect of prescribed exercise programmes performed in the home or community with minimal supervision, by adults living with HIV. The following will be searched from inception: PubMed, Embase, Scopus, Cumulative Index to Nursing and Allied Health Literature, Physiotherapy Evidence Database, SPORTDiscus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Clinicaltrials.gov. Screening of studies and data extraction will be conducted by two independent reviewers. The risk of bias in included studies will be assessed using version 2 of the Cochrane risk-of-bias tool for randomized trials (RoB 2) and the Risk of Bias In Non-Randomized Studies-of Interventions (ROBINS-I) tool for non-randomized concurrently controlled and single-arm interventional studies. A random effects meta-analysis will be used to pool effect estimates for outcomes of interest (measures of physical activity and body adiposity). However, if pooling is deemed inappropriate due to substantial differences between studies, a narrative synthesis will be performed. This protocol is written according to the Preferred Reporting Items for Systematic reviews and Meta-analysis Protocols 2015 statement (see Additional file 1). DISCUSSION: This review shall provide evidence to support or disapprove the prescription of self-managed exercise interventions in a particularly vulnerable population. We will equally explore the potential impact of technology in improving physical activity outcomes. Our findings could help guide clinicians involved in the care of PLWH in prescribing exercise and inform the design of future trials and research. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021223357 .

The influence of exercise training volume alterations on the gut microbiome in highly-trained middle-distance runners.

The aim of this study was to determine the influence of training volume alterations on diversity and composition of the gut microbiome in a free-living cohort of middle-distance runners. Fourteen highly-trained middle-distance runners (n = 8 men; V˙O2peak = 70.1 ± 4.3 ml·kg·min-1; n = 6 women, V˙O2peak: 59.0 ± 3.2 ml·kg·min-1) completed three weeks of normal training (NormTr), three weeks of high-volume training (HVolTr; a 10, 20 and 30% increase in training volume during each successive week from NormTr), and a one-week taper (TaperTr; 55% exponential reduction in training volume from HVolTr week three). Faecal samples were collected before and immediately after each training phase to quantify alpha-diversity and composition of the gut microbiome. A three-day diet record was collected during each training phase and a maximal incremental running test was completed after each training phase. Results showed no significant changes in nutritional intake, alpha-diversity, or global microbial composition following HVolTr or TaperTr compared to NormTr (p's > 0.05). Following HVolTr, there was a significant decrease in Pasterellaceae (p = 0.03), Lachnoclostridium (p = 0.02), Haemophilus (p = 0.03), S. parasagunis (p = 0.02), and H. parainfluenzae (p = 0.03), while R. callidus (p = 0.03) significantly increased. These changes did not return to NormTr levels following TaperTr. This study shows that the alpha-diversity and global composition of the gut microbiome were unaffected by changes in training volume. However, an increase in training volume led to several changes at the lower taxonomy levels that did not return to pre-HVolTr levels following a taper period.

Youth Athlete Development and Nutrition.

Adolescence (ages 13-18 years) is a period of significant growth and physical development that includes changes in body composition, metabolic and hormonal fluctuations, maturation of organ systems, and establishment of nutrient deposits, which all may affect future health. In terms of nutrition, adolescence is also an important time in establishing an individual's lifelong relationship with food, which is particularly important in terms of the connection between diet, exercise, and body image. The challenges of time management (e.g., school, training, work and social commitments) and periods of fluctuating emotions are also features of this period. In addition, an adolescent's peers become increasingly powerful moderators of all behaviours, including eating. Adolescence is also a period of natural experimentation and this can extend to food choice. Adolescent experiences are not the same and individuals vary considerably in their behaviours. To ensure an adolescent athlete fulfils his/her potential, it is important that stakeholders involved in managing youth athletes emphasize eating patterns that align with and support sound physical, physiological and psychosocial development and are consistent with proven principles of sport nutrition.

The impact of post-prandial delay periods on ad libitum consumption of a laboratory breakfast meal.

This study examined the impact of varying the holding time following an ad libitum laboratory breakfast on acute dietary behaviour and subsequent intake. Twenty-four participants (20 females (age: 23.4 ± 6.3 years; body mass index: 23.9 ± 3.9 kg·m-2, mean ± SD)) completed 3 trials following a quasi-randomised, crossover design. Each trial (7-day separation) incorporated a defined post-prandial delay (DPD) period of either zero (no delay), 1 or 3 hours following a buffet breakfast consumed over 30 minutes. Dietary intake outcomes included energy, macronutrient and core food group intakes. On completion of the DPD period, participants left the laboratory and recorded all food/beverages consumed for the remainder of the day. One-way repeated-measures ANOVA assessed all outcomes, with post hoc analysis conducted on significant main effects. Energy and carbohydrate intakes were significantly lower on no delay vs. 1-hour (p = 0.014) and 3-hour (p = 0.06) DPD trials (energy intake: 1853 ± 814 kJ vs. 2250 ± 1345 kJ vs. 1948 ± 1289 kJ; carbohydrates: 68 ± 34 g vs. 77 ± 44 vs. 69 ± 43 g; respectively). DPD periods did not influence the time to consume next meal or energy, macronutrient and core food group intakes for the remainder of the day. Delaying participants from leaving a laboratory alters dietary intake at an ad libitum test meal. The post-meal holding period is an important methodological consideration when planning laboratory studies to assess appetite. Novelty: Delaying participants from leaving a laboratory alters dietary intake at ad libitum breakfast meals. The length of the delay period did not affect dietary intake at ad libitum breakfast meals.

Belief in caffeine's ergogenic effect on cognitive function and endurance performance: A sham dose-response study.

This study aimed to determine if belief in caffeine's ergogenic potential influences choice reaction time (CRT) and/or running performance. Twenty-nine healthy individuals (23.7 ± 5 years, 16 males) completed two trials (one week apart). Before the trials, participants indicated their "belief" in caffeine's ergogenic effects and previous "experience" using caffeine for performance. On arrival, participants randomly received either sham "Low (100mg; LD)" or "High (300mg; HD)" dose caffeine capsules 30-min before commencing the CRT test, followed by a 10km run. Paired samples t-tests determined differences between trials for CRT latency (Ex-Gaussian analysis; µ-, σ- and τ-) and running performance using the entire cohort and sub-groups exhibiting strong "beliefs"+/-"experience". Sham caffeine dose did not influence CRT (µ-, σ- and τ-respectively, LD: 400 ± 53ms vs. HD: 388 ± 41ms; LD: 35 ± 18ms vs. HD: 34 ± 17ms; LD: 50 ± 24ms vs. HD: 52 ± 19ms, all p's > 0.05). Neither belief (n = 6), nor belief + experience (n = 4), influenced this effect. Furthermore, caffeine dose did not influence run time (LD: 49.05 ± 3.75min vs. HD: 49.06 ± 3.85min, p = 0.979). Belief (n = 9) (LD: 48.93 ± 3.71min vs. HD: 48.9 ± 3.52min, p = 0.976), and belief + experience (n = 6) (LD: 48.68 ± 1.87min vs. HD: 49.55 ± 1.75min, p = 0.386) didn't influence this effect. A dose-response to sham caffeine ingestion was not evident on cognitive or endurance performance in healthy individuals, regardless of their convictions about caffeine's ergogenicity.

Assessment of an integrated knowledge translation intervention to improve nutrition intakes among patients undergoing elective bowel surgery: a mixed-method process evaluation.

BACKGROUND: A large evidence-practice gap exists regarding provision of nutrition to patients following surgery. The aim of this study was to evaluate the processes supporting the implementation of an intervention designed to improve the timing and adequacy of nutrition following bowel surgery. METHODS: A mixed-method pilot study, using an integrated knowledge translation (iKT) approach, was undertaken at a tertiary teaching hospital in Australia. A tailored, multifaceted intervention including ten strategies targeted at staff or patients were co-developed with knowledge users at the hospital and implemented in practice. Process evaluation outcomes included reach, intervention delivery and staffs' responses to the intervention. Quantitative data, including patient demographics and surgical characteristics, intervention reach, and intervention delivery were collected via chart review and direct observation. Qualitative data (responses to the intervention) were sequentially collected from staff during one-on-one, semi-structured interviews. Quantitative data were summarized using median (IQR), mean (SD) or frequency(%), while qualitative data were analysed using content analysis. RESULTS: The intervention reached 34 patients. Eighty-four percent of nursing staff received an awareness and education session, while 0% of medical staff received a formal orientation or awareness and education session, despite the original intention to deliver these sessions. Several strategies targeted at patients had high fidelity, including delivery of nutrition education (92%); and prescription of oral nutrition supplements (100%) and free fluids immediately post-surgery (79%). Prescription of a high energy high protein diet on postoperative day one (0%) and oral nutrition supplements on postoperative day zero (62%); and delivery of preoperative nutrition handout (74%) and meal ordering education (50%) were not as well implemented. Interview data indicated that staff regard nutrition-related messages as important, however, their acceptance, awareness and perceptions of the intervention were mixed. CONCLUSIONS: Approximately half the patient-related strategies were implemented well, which is likely attributed to the medical and nursing staff involved in intervention design championing these strategies. However, some strategies had low delivery, which was likely due to the varied awareness and acceptance of the intervention among staff on the ward. These findings suggest the importance of having buy-in from all staff when using an iKT approach to design and implement interventions.

Analysis of dietary intake, diet cost and food group expenditure from a 24-hour food record collected in a sample of Australian university students.

AIM: University students often cite increased monetary cost as a major barrier to improved eating behaviours. Here, we examine food expenditure behaviours in a sample of Australian university students. METHODS: Students (n = 147) collected and analysed a 24-hour food record to determine their food group and nutrient intakes, then costed the food and non-tap water beverages consumed in the amounts recorded. Diet cost and food group expenditure (absolute and relative to total diet cost) were calculated and compared across socio-demographic characteristics. Spearman's Rho correlations and partial correlations (controlling for energy intake) were also used to identify associations between diet cost and intake. RESULTS: The median (IQR) 24-hour diet cost was $12.42 ($7.06). However, students who worked ≥20 h·wk-1 had a higher diet cost than those who worked <20 h·wk-1 (P = .002) or were unemployed (P = .002). Relative food group expenditure also differed by sex, employment status and whether special dietary requirements were reported (P's < .05). For instance, males reported spending a smaller relative amount on the fruit and vegetables food groups and a larger relative amount on discretionary choices than females (P's < 0.05). Higher diet costs were also associated with greater intakes of the fruit, vegetables and lean meat and alternatives food groups, protein, alcohol, water and calcium, and lower intakes of the grain foods food group and carbohydrate (P's < .05). CONCLUSIONS: These findings provide insight into university students' food expenditure behaviours and may assist health professionals to develop targeted strategies and tailored advice aimed at improving their dietary behaviours.

The Effect of Consuming Carbohydrate With and Without Protein on the Rate of Muscle Glycogen Re-synthesis During Short-Term Post-exercise Recovery: a Systematic Review and Meta-analysis.

BACKGROUND: Rapid restoration of muscle glycogen stores is imperative for athletes undertaking consecutive strenuous exercise sessions with limited recovery time (e.g. ≤ 8 h). Strategies to optimise muscle glycogen re-synthesis in this situation are essential. This two-part systematic review and meta-analysis investigated the effect of consuming carbohydrate (CHO) with and without protein (PRO) on the rate of muscle glycogen re-synthesis during short-term post-exercise recovery (≤ 8 h). METHODS: Studies were identified via the online databases Web of Science and Scopus. Investigations that measured muscle glycogen via needle biopsy during recovery (with the first measurement taken ≤ 30 min post-exercise and at least one additional measure taken ≤ 8 h post-exercise) following a standardised exercise bout (any type) under the following control vs. intervention conditions were included in the meta-analysis: part 1, water (or non-nutrient beverage) vs. CHO, and part 2, CHO vs. CHO+PRO. Publications were examined for methodological quality using the Rosendal scale. Random-effects meta-analyses and meta-regression analyses were conducted to evaluate intervention efficacy. RESULTS: Overall, 29 trials (n = 246 participants) derived from 21 publications were included in this review. The quality assessment yielded a Rosendal score of 61 ± 8% (mean ± standard deviation). Part 1: 10 trials (n = 86) were reviewed. Ingesting CHO during recovery (1.02 ± 0.4 g·kg body mass (BM)-1 h-1) improved the rate of muscle glycogen re-synthesis compared with water; change in muscle glycogen (MGΔ) re-synthesis rate = 23.5 mmol·kg dm-1 h-1, 95% CI 19.0-27.9, p < 0.001; I2 = 66.8%. A significant positive correlation (R2 = 0.44, p = 0.027) was observed between interval of CHO administration (≤ hourly vs. > hourly) and the mean difference in rate of re-synthesis between treatments. Part 2: 19 trials (n = 160) were reviewed. Ingesting CHO+PRO (CHO: 0.86 ± 0.2 g·kg BM-1 h-1; PRO: 0.27 ± 0.1 g·kg BM-1 h-1) did not improve the rate of muscle glycogen re-synthesis compared to CHO alone (0.95 ± 0.3 g·kg BM-1 h-1); MGΔ re-synthesis rate = 0.4 mmol·kg dm-1 h-1, 95% CI -2.7 to 3.4, p = 0.805; I2 = 56.4%. CONCLUSIONS: Athletes with limited time for recovery between consecutive exercise sessions should prioritise regular intake of CHO, while co-ingesting PRO with CHO appears unlikely to enhance (or impede) the rate of muscle glycogen re-synthesis. TRIAL REGISTRATION: Registered at the International Prospective Register of Systematic Reviews (PROSPERO) (identification code CRD42020156841 ).

Cognitive effects of acute aerobic exercise: Exploring the influence of exercise duration, exhaustion, task complexity and expectancies in endurance-trained individuals.

The cognitive effects of acute aerobic exercise were investigated in endurance-trained individuals. On two occasions, 21 cyclists; 11 male (VO2max: 57 ± 9 mL·kg-1·min-1) and 10 female (VO2max: 51 ± 9 mL·kg-1·min-1), completed 45 min of fixed, moderate-intensity (discontinuous) cycling followed by an incremental ride to exhaustion. Cognitive function was assessed at Baseline, after 15 and 45 min of exercise (15EX and 45EX) and at Exhaustion using a 4-Choice Reaction Time (CRT) test and the Stroop test (Incongruent and Congruent Reaction Time [RT]). A sham capsule was administered on one occasion to determine whether the cognitive response to exercise was robust to the influence of a placebo. CRT, Congruent RT and Incongruent RT decreased (improved) at 15EX, 45EX and Exhaustion compared to Baseline (p's<0.005). While CRT and Congruent RT were faster at 45EX than 15EX (p's<0.020), Incongruent RT was not (p= 1.000). The sham treatment did not affect cognition. When performed at a moderate-intensity, longer duration exercise (up to 45 min) may improve cognition to a greater extent than shorter duration exercise; however, the magnitude of improvement appears to decrease with increasing task complexity. HI/EE performed following a sustained bout of dehydrating activity may not impair cognition.