Artificial intelligence in sport: Exploring the potential of using ChatGPT in resistance training prescription.

OpenAI's Chat Generative Pre-trained Transformer (ChatGPT) technology enables conversational interactions with applications across various fields, including sport. Here, ChatGPT's proficiency in designing a 12-week resistance training programme, following specific prompts, was investigated. GPT3.5 and GPT4.0 versions were requested to design 12-week resistance training programmes for male and female hypothetical subjects (20-years-old, no injury, and 'intermediate' resistance training experience). Subsequently, GPT4.0 was requested to design an 'advanced' training programme for the same profiles. The proposed training programmes were compared with established guidelines and literature (e.g., National Strength and Conditioning Association textbook), and discussed. ChatGPT suggested 12-week training programmes comprising three, 4-week phases, each with different objectives (e.g., hypertrophy/strength). GPT3.5 proposed a weekly frequency of ~3 sessions, load intensity of 70-85% of one repetition-maximum, repetition range of 4-8 (2-4 sets), and tempo of 2/0/2 (eccentric/pause/concentric/'pause'). GPT4.0 proposed intermediate- and advanced programme, with a frequency of 5 or 4 sessions, 60-90% or 70-95% intensity, 3-5 sets or 3-6 sets, 5-12 or 3-12 repetitions, respectively. GPT3.5 proposed rest intervals of 90-120 s, and exercise tempo of 2/0/2. GPT4.0 proposed 60-180 (intermediate) or 60-300 s (advanced), with exercise tempo of 2/1/2 for intermediates, and 3/0/1/0, 2/0/1/0, and 1/0/1/0 for advanced programmes. All derived programmes were objectively similar regardless of sex. ChatGPT generated training programmes which likely require additional fine-tuning before application. GPT4.0 synthesised more information than GPT3.5 in response to the prompt, and demonstrated recognition awareness of training experience (intermediate vs advanced). ChatGPT may serve as a complementary tool for writing 'draft' programme, but likely requires human expertise to maximise training programme effectiveness.

Cross-adaptation from heat stress to hypoxia: A systematic review and exploratory meta-analysis.

Cross-adaptation (CA) refers to the successful induction of physiological adaptation under one environmental stressor (e.g., heat), to enable subsequent benefit in another (e.g., hypoxia). This systematic review and exploratory meta-analysis investigated the effect of heat acclimation (HA) on physiological, perceptual and physical performance outcome measures during rest, and submaximal and maximal intensity exercise in hypoxia. Database searches in Scopus and MEDLINE were performed. Studies were included when they met the Population, Intervention, Comparison, and Outcome criteria, were of English-language, peer-reviewed, full-text original articles, using human participants. Risk of bias and study quality were assessed using the COnsensus based Standards for the selection of health status Measurement INstruments checklist. Nine studies were included, totalling 79 participants (100 % recreationally trained males). The most common method of HA included fixed-intensity exercise comprising 9 ± 3 sessions, 89 ± 24-min in duration and occurred within 39 ± 2 °C and 32 ± 13 % relative humidity. CA induced a moderate, beneficial effect on physiological measures at rest (oxygen saturation: g = 0.60) and during submaximal exercise (heart rate: g = -0.65, core temperature: g = -0.68 and skin temperature: g = -0.72). A small effect was found for ventilation (g = 0.24) and performance measures (peak power: g = 0.32 and time trial time: g = -0.43) during maximal intensity exercise. No effect was observed for perceptual outcome measures. CA may be appropriate for individuals, such as occupational or military workers, whose access to altitude exposure prior to undertaking submaximal activity in hypoxic conditions is restricted. Methodological variances exist within the current literature, and females and well-trained individuals have yet to be investigated. Future research should focus on these cohorts and explore the mechanistic underpinnings of CA.

Disproportionate Rates of COVID-19 Among Black Canadian Communities: Lessons from a Cross-Sectional Study in the First Year of the Pandemic.

BACKGROUND: Racialized communities, including Black Canadians, have disproportionately higher COVID-19 cases. We examined the extent to which SARS-CoV-2 infection has affected the Black Canadian community and the factors associated with the infection. METHODS: We conducted a cross-sectional survey in an area of Ontario (northwest Toronto/Peel Region) with a high proportion of Black residents along with 2 areas that have lower proportions of Black residents (Oakville and London, Ontario). SARS-CoV-2 IgG antibodies were determined using the EUROIMMUN assay. The study was conducted between August 15, 2020, and December 15, 2020. RESULTS: Among 387 evaluable subjects, the majority, 273 (70.5%), were enrolled from northwest Toronto and adjoining suburban areas of Peel, Ontario. The seropositivity values for Oakville and London were comparable (3.3% (2/60; 95% CI 0.4-11.5) and 3.9% (2/51; 95% CI 0.5-13.5), respectively). Relative to these areas, the seropositivity was higher for the northwest Toronto/Peel area at 12.1% (33/273), relative risk (RR) 3.35 (1.22-9.25). Persons 19 years of age or less had the highest seropositivity (10/50; 20.0%, 95% CI 10.3-33.7%), RR 2.27 (1.23-3.59). There was a trend for an interaction effect between race and location of residence as this relates to the relative risk of seropositivity. INTERPRETATION: During the early phases of the pandemic, the seropositivity within a COVID-19 high-prevalence zone was threefold greater than lower prevalence areas of Ontario. Black individuals were among those with the highest seroprevalence of SARS-CoV-2.

Knowledge About Renal Transplantation Among African, Caribbean, and Black Canadian Patients With Advanced Kidney Failure.

Introduction: Variable transplant-related knowledge may contribute to inequitable access to living donor kidney transplant (LDKT). We compared transplant-related knowledge between African, Caribbean, and Black (ACB) versus White Canadian patients with kidney failure using the Knowledge Assessment of Renal Transplantation (KART) questionnaire. Methods: This was a cross-sectional cohort study. Data were collected from a cross-sectional convenience sample of adults with kidney failure in Toronto. Participants also answered an exploratory question about their distrust in the kidney allocation system. Clinical characteristics were abstracted from medical records. The potential contribution of distrust to differences in transplant knowledge was assessed in mediation analysis. Results: Among 577 participants (mean [SD] age 57 [14] years, 63% male), 25% were ACB, and 43% were White Canadians. 45% of ACB versus 26% of White participants scored in the lowest tertile of the KART score. The relative risk ratio to be in the lowest tertile for ACB compared to White participants was 2.22 (95% confidence interval [CI]: 1.11, 4.43) after multivariable adjustment. About half of the difference in the knowledge score between ACB versus White patients was mediated by distrust in the kidney allocation system. Conclusion: Participants with kidney failure from ACB communities have less transplant-related knowledge compared to White participants. Distrust is potentially contributing to this difference.

Exploring barriers to living donor kidney transplant for African, Caribbean and Black communities in the Greater Toronto Area, Ontario: a qualitative study protocol.

INTRODUCTION: Living donor (LD) kidney transplant (KT) is the best treatment option for many patients with kidney failure as it improves quality of life and survival compared with dialysis and deceased donor KT. Unfortunately, LDKT is underused, especially among groups marginalised by race and ethnicity. African, Caribbean and Black (ACB) patients are 60%-70% less likely to receive LDKT in Canada compared with white patients. Research from the USA and the UK suggests that mistrust, cultural and generational norms, access, and affordability may contribute to inequities. To date, no Canadian studies have explored the beliefs and behaviours related to LDKT in ACB communities. Research approaches that use a critical, community-based approach can help illuminate broader structural factors that may shape individual beliefs and behaviours. In this qualitative study, we will investigate barriers to accessing LDKT in ACB communities in the Greater Toronto Area, to enhance our understanding of the perspectives and experiences of ACB community members, both with and without lived experience of chronic kidney disease (CKD). METHODS AND ANALYSIS: Hospital-based and community-based recruitment strategies will be used to recruit participants for focus groups and individual interviews. Participants will include self-identified ACB individuals with and without experiences of CKD and nephrology professionals. Collaboration with ACB community partners will facilitate a community-based research approach. Data will be analysed using reflexive thematic analysis and critical race theory. Findings will be revised based on feedback from ACB community partners. ETHICS AND DISSEMINATION: This study has been approved by the University Health Network Research Ethics Board UHN REB file #15-9775. Study findings will contribute to the codevelopment of culturally safe and responsive educational materials to raise awareness about CKD and its treatments and to improve equitable access to high-quality kidney care, including LDKT, for ACB patients.

Blood Lactate Responses of Male and Female Players Across an International Rugby Sevens Tournament.

PURPOSE: This study investigated within- and between-matches blood lactate (La-) responses across an international Rugby Sevens tournament (5 matches over 2 d) in male and female players. METHODS: Earlobe blood samples were taken from 25 professional players around matches: before warm-up (PRE), immediately upon finishing match participation (POST), and 30 minutes postmatch (30 min). RESULTS: POST [La-] (mean [SD], range) for males was 10.3 (3.2; 2.9-20.2) mmol·L-1 and for females was 9.1 (2.3; 3.4-14.6) mmol·L-1. Linear mixed-effects models revealed a decrease in POST [La-] after match 5, compared to match 1. Increased PRE [La-] was found before match 2 (+0.8 [0.6-1.1] mmol·L-1), match 3 (+0.8 [0.5-1.1] mmol·L-1), and match 5 (+0.6 [0.4-0.9] mmol·L-1) compared to match 1 (all P < .001). The [La-] remained elevated at 30 min, compared to PRE (+1.7 [1.4-2.0] mmol·L-1, P < .001), with ∼20% of values persisting >4 mmol·L-1. Higher POST was observed in males compared to females (+1.6 [0.1-3.2] mmol·L-1, P = .042); however, no differences between sexes were found across 30 min or PRE [La-]. No [La-] differences between positions (backs and forwards) were identified. CONCLUSIONS: Lactate concentrations above 10 mmol·L-1 are required to effectively simulate the anaerobic demands of international Rugby Sevens matches. Practitioners are advised to individualize anaerobic training prescription due to the substantial variability observed within positional groups. Additionally, improving athletes' metabolic recovery capacity through training, nutrition, and recovery interventions may enhance physical preparation for subsequent matches within a day, where incomplete lactate clearance was observed.

Physiological characteristics and performance of a world-record breaking tower runner.

This study reports the physiological and performance profiles of a world-class tower runner during a 6-week period surrounding a successful Guinness World Record (WR) attempt, and discusses the efficacy of a tower running specific field test. The world-ranked number 2 tower runner completed four exercise tests [laboratory treadmill assessment (3 weeks before the WR attempt), familiarisation to a specific incremental tower running field test (1 week before), tower running field test (1 week after), and tower running time trial (TT) (3 weeks after)] and the WR attempt within 6-week period. Peak oxygen consumption (VO2peak) during the laboratory test, field test, and TT were 73.3, 75.5 and 78.3 mL·kg-1·min-1, respectively. The VO2 corresponding to the second ventilatory threshold was 67.3 mL·kg-1·min-1 (89.1% of VO2peak), identified at stage 4 (tempo; 100 b·min-1), during the field test. The duration of the TT was 10 min 50 s, with an average VO2 of 71.7 mL·kg-1·min-1 (91.6% of VO2peak), HR of 171 b·min-1 (92% of peak HR), vertical speed of 0.47 m·s-1, and cadence was 117 steps·min-1. A world-class tower runner possesses a well-developed aerobic capacity. A specific, field-based test revealed greater VO2peak than a laboratory test, indicating a need for sport-specific testing procedures.

Psychosocial Distress in Patients With Advanced CKD by Racial Group and Immigrant Status: A Canadian Cross-sectional Study.

RATIONALE & OBJECTIVE: Patients with advanced chronic kidney disease (CKD) have been reported to experience profound psychosocial distress. Other work has established that patients with CKD from marginalized populations (including individuals who on the basis of race often face racism and related discrimination, termed "racialization") experience health care inequities. Given limited information on the intersection of these 2 phenomena, we assessed the association of psychosocial distress with racialized status and immigrant status in Canadians with advanced CKD. STUDY DESIGN: Secondary analysis of cross-sectional data. SETTING & PARTICIPANTS: 536 patients with advanced CKD (estimated glomerular filtration rate<30mL/min/1.73m2, with or without kidney replacement therapy) from multiple clinical centers in Toronto. EXPOSURE: Racialized status (individuals who identify as Asian or as African, Caribbean, or Black Canadian), immigrant status, and combined immigrant-racialized status. OUTCOME: Psychosocial distress, defined as the presence of depression, anxiety, or social difficulties (ie, a score of≥10 points on the Patient Health Questionnaire 9, Generalized Anxiety Disorder 7, or Social Distress 16 scales, respectively). ANALYTICAL APPROACH: The independent associations of racialized status and immigrant status with psychosocial distress, depression, anxiety, and social difficulties were examined using univariable- and multivariable-adjusted logistic regression. RESULTS: Mean age of the 536 participants was 57±16 (SD) years, 62% were male, and 45% were immigrants. Of the sample, 58% were White, 22% were African, Caribbean, or Black Canadian, and 20% were Asian. Psychosocial distress was present in 36% of participants (depression in 19%, anxiety in 12%, and social difficulties in 31%). To assess the combined impact of racialized and immigrant status, we created a variable with mutually exclusive categories: White nonimmigrant, racialized nonimmigrant, White immigrant, and racialized immigrant participants. In our final multivariable-adjusted model, compared with White nonimmigrant participants, racialized immigrant participants were more likely to have psychosocial distress (OR, 2.96 [95% CI, 1.81-4.81]), depression (OR, 1.87 [95% CI, 1.05-3.34]), and social difficulties (OR, 3.36 [95% CI, 2.03-5.57]). Overall similar associations were seen for racialized nonimmigrants and for White immigrants. LIMITATIONS: Convenience sample; small subgroups; combined exposure variable grouping Asian and African, Caribbean, and Black participants together; lack of data about mechanisms. CONCLUSIONS: Both racialized and immigrant status based on self-report of demographic characteristics were associated with psychosocial distress among patients with advanced CKD. These patients may benefit from culturally competent psychosocial support. PLAIN-LANGUAGE SUMMARY: Psychosocial distress is frequent in patients with advanced chronic kidney disease and impacts quality of life and clinical outcomes. Psychosocial distress may be especially scarring in people who are racialized (marginalized on account of their membership in a particular racial group) and/or who are immigrants. We assessed the association of psychosocial distress with racialized and immigrant status in Canadians with advanced chronic kidney disease. Among 536 participants from multiple medical centers in Toronto, we found that racialized and immigrant participants were more likely to have psychosocial distress, depression, and social difficulties compared with White nonimmigrant participants. This is likely related to the multiple intersectional challenges, including experience with racism and discrimination that racialized immigrant patients may face. Further studies are needed to elucidate the specific factors that contribute to more distress. The potential impact of culturally competent and safe support for these patients will also need to be studied.

"You have to make it cool": How heterosexual Black men in Toronto, Canada, conceptualize policy and programs to address HIV and promote health.

BACKGROUND: Black Canadian communities are disproportionately impacted by HIV. To help address this challenge, we undertook research to engage heterosexual Black men in critical dialogue about resilience and vulnerability. They articulated the necessity of making health services 'cool'. METHODS: We draw on the analyses of focus groups and in-depth interviews with 69 self-identified heterosexual Black men and 12 service providers who took part in the 2016 Toronto arm of the weSpeak study to explore what it means to make health and HIV services 'cool' for heterosexual Black Canadian men. RESULTS: Our findings revealed four themes on making health services cool: (1) health promotion as a function of Black family systems; (2) opportunities for healthy dialogue among peers through non-judgmental interactions; (3) partnering Black men in intervention design; and (4) strengthening institutional health literacy on Black men's health. CONCLUSIONS: We discuss the implications of these findings for improving the health of Black Canadians.

Increased air temperature decreases high-speed, but not total distance, in international field hockey.

This study investigated the effect of heat stress on locomotor activity within international field hockey at team, positional and playing-quarter levels. Analysis was conducted on 71 matches played by the Malaysia national men's team against 24 opponents. Fixtures were assigned to match conditions, based on air temperature [COOL (14 ± 3°C), WARM (24 ± 1°C), HOT (27 ± 1°C), or VHOT (32 ± 2°C), p < 0.001]. Relationships between locomotor metrics and air temperature (AIR), absolute and relative humidity, and wet bulb globe temperature (WBGT) were investigated further using correlation and regression analyses. Increased AIR and WBGT revealed similar correlations (p < 0.01) with intensity metrics; high-speed running (AIR r = -0.51, WBGT r = -0.45), average speed (AIR r = -0.48, WBGT r = -0.46), decelerations (AIR r = -0.41, WBGT r = -0.41), sprinting efforts (AIR r = -0.40, WBGT r = -0.36), and sprinting distance (AIR r = -0.37, WBGT r = -0.29). In comparison to COOL, HOT, and VHOT matches demonstrated reduced high-speed running intensity (-14-17%; p < 0.001), average speed (-5-6%; p < 0.001), sprinting efforts (-17%; p = 0.010) and decelerations per min (-12%; p = 0.008). Interactions were found between match conditions and playing quarter for average speed (+4-7%; p = 0.002) and sprinting distance (+16-36%; p < 0.001), both of which were higher in the fourth quarter in COOL versus WARM, HOT and VHOT. There was an interaction for "low-speed" (p < 0.001), but not for "high-speed" running (p = 0.076) demonstrating the modulating effect of air temperature (particularly >25°C) on pacing within international hockey. These are the first data demonstrating the effect of air temperature on locomotor activity within international men's hockey, notably that increased air temperature impairs high-intensity activities by 5-15%. Higher air temperatures compromise high-speed running distances between matches in hockey.

Physiological and Performance Correlates of Squash Physical Performance.

The physiological and performance attributes of elite squash players were investigated. Thirty-one players (21 males, world ranking [WR] 42-594; 10 females, WR 7-182) completed a battery of fitness tests which included an aerobic squash-specific physical performance test (SPPT), repeated-sprint ability (RSA), change-of-direction speed (COD), acceleration (5-m sprint), body composition and force development (countermovement jump) assessments. The SPPT provided a finishing lap score, V̇O2max, average movement economy and the lap corresponding to a blood lactate concentration of 4 mM.L-1. Players were ranked and assigned to HIGH or LOW performance tiers. Two-way ANOVA (performance level*sex) revealed higher ranked players performed better (p < 0.05) for SPPT final lap (d = 0.35), 4 mM.L-1 lap (d = 0.52) and COD (d = 0.60). SPPT displayed a 'very-large' correlation with 4 mM.L-1 lap (r = 0.86), 'large' correlations with COD (r = 0.79), RSA (r = 0.79), sum-of-7 skinfolds (r = 0.71) and V̇O2max (r = 0.69), and a 'trivial' correlation with average movement economy (r = 0.02). Assessments of cardiovascular fitness (i.e. 4 mM.L-1 lap), RSA, COD and body composition appear highly pertinent for performance profiling of squash players. Regular, submaximal assessment of the 4 mM.L-1 lap during the SPPT may offer a practical athlete monitoring approach for elite squash players.

Athlete level, sport-type, and gender influences on training, mental health, and sleep during the early COVID-19 lockdown in Malaysia.

Purpose: We evaluated the extent of changes in training practices, recovery, mental health, and sleep patterns of athletes during the early COVID-19 lockdown in a single country-cohort. Methods: A total of 686 athletes (59% male, 41% female; 9% World Class, 28% International, 29% National, 26% State, 8% Recreational) from 50 sports (45% individual, 55% team) in Malaysia completed an online, survey-based questionnaire study. The questions were related to training practices (including recovery and injury), mental health, and sleep patterns. Results: Relative to pre-lockdown, training intensity (-34%), frequency (-20%, except World-Class), and duration (-24%-59%, especially International/World-Class) were compromised, by the mandated lockdown. During the lockdown, more space/access (69%) and equipment (69%) were available for cardiorespiratory training, than technical and strength; and these resources favoured World-Class athletes. Most athletes trained for general strength/health (88%) and muscular endurance (71%); and some used innovative/digital training tools (World-Class 48% vs. lower classification-levels ≤34%). More World-Class, International, and National athletes performed strength training, plyometrics, and sport-specific technical skills with proper equipment, than State/Recreational athletes. More females (42%) sourced training materials from social media than males (29%). Some athletes (38%) performed injury prevention exercises; 18% had mild injuries (knees 29%, ankles 26%), and 18% received a medical diagnosis (International 31%). Lower-level athletes (e.g., State 44%) disclosed that they were mentally more vulnerable; and felt more anxious (36% vs. higher-levels 14%-21%). Sleep quality and quantity were "normal" (49% for both), "improved" (35% and 27%), and only 16% and 14% (respectively) stated "worsened" sleep. Conclusion: Lockdown compromised training-related practices, especially in lower-level athletes. Athletes are in need of assistance with training, and tools to cope with anxiety that should be tailored to individual country requirements during lockdown situations. In particular, goal-driven (even if it is at home) fitness training, psychological, financial, and lifestyle support can be provided to reduce the difficulties associated with lockdowns. Policies and guidelines that facilitate athletes (of all levels) to train regularly during the lockdown should be developed.

Volume and Intensity of Locomotor Activity in International Men's Field Hockey Matches Over a 2-Year Period.

The locomotor demands of international men's field hockey matches were investigated across positions (DEF, MID, FWD) and playing quarters. Volume (i.e., total values) and intensity (i.e., relative to playing time) data were collected using 10-Hz GPS/100-Hz accelerometer units from the #11 world-ranked (WR) team, during 71 matches, against 24 opponents [WR 12 ± 11 (range, 1-60)]. Mean ± SD team total distance (TD) was 4,861 ± 871 m, with 25% (1,193 ± 329 m) "high-speed running" (>14.5 km h-1) and 8% (402 ± 144 m) "sprinting" (>19.0 km h-1). Reduced TD (range, -3 to 4%) and average speed (range, -3.4 to 4.7%) occurred through subsequent quarters, vs. Q1 (p < 0.05). A "large" negative relationship (r = -0.64) was found between playing duration and average speed. Positional differences (p < 0.05) were identified for all volume metrics including; playing duration (DEF, 45:50 ± 8:00 min; MID, 37:37 ± 7:12 min; FWD, 33:32 ± 6:22 min), TD (DEF, 5,223 ± 851 m; MID, 4,945 ± 827 m; FWD, 4,453 ± 741 m), sprinting distance (DEF, 315 ± 121 m; MID, 437 ± 144 m; FWD, 445 ± 129 m), and acceleration efforts (>2 m s-2; DEF, 48 ± 12; MID, 51 ± 11; FWD, 50 ± 14). Intensity variables similarly revealed positional differences (p < 0.05) but with a different pattern between positions; average speed (DEF, 115 ± 10 m min-1; MID, 132 ± 10 m min-1; FWD, 134 ± 15 m min-1), sprinting (DEF, 7 ± 3 m min-1; MID, 12 ± 4 m min-1; FWD, 14 ± 4 m min-1), and accelerations (DEF, 1.1 ± 0.3 n min-1; MID, 1.4 ± 0.2 n min-1; FWD, 1.5 ± 0.3 n min-1). Physical outputs reduced across playing quarters, despite unlimited substitutions, demonstrating the importance of optimizing physical preparation prior to international competition. Volume and intensity data highlight specific positional requirements, with forwards displaying shorter playing durations but greater high-intensity activities than defenders.

Minimal Agreement between Internal and External Training Load Metrics across a 2-wk Training Microcycle in Elite Squash.

This study investigated the relationships between internal and external training load metrics across a 2-week 'in-season' microcycle in squash. 134 on-court and 32 off-court 'conditioning' sessions were completed by fifteen elite squash players with an average (±SD) of 11 ± 3 per player. During every session, external load was captured using a tri-axial accelerometer to calculate Playerload; i.e., the instantaneous rate of change of acceleration across 3-dimensional planes. Internal load was measured using heart rate (HR), global (sRPE) and differential RPE (dRPE-Legs, dRPE-Breathing). Additionally, HR was used to calculate Banister's, Edward's and TEAM TRIMPs. Across 166 training sessions, Playerload was moderately correlated with TRIMP-Banister (r = 0.43 [95% CI: 0.29-0.55], p < 0.001) and TRIMP-Edwards (r = 0.50 [0.37-0.61], p < 0.001). Association of Playerload with TRIMP-TEAM (r = 0.24 [0.09-0.38], p = 0.001) was small. There was a moderate correlation between sRPE and Playerload (r = 0.46 [0.33-0.57], p < 0.001). Association of sRPE was large with TRIMP-Banister (r = 0.68 [0.59-0.76], p = 0.001), very large with TRIMP-Edwards (r = 0.79 [0.72-0.84], p < 0.001) and moderate with TRIMP-TEAM (r = 0.44 [0.31-0.56], p < 0.001). Both dRPE-Legs (r = 0.95 [0.93-0.96], p < 0.001) and dRPE-Breathing (r = 0.92 [0.89-0.94], p < 0.001) demonstrated nearly perfect correlations with sRPE and with each other (r = 0.91 [0.88-0.93], p < 0.001). Collection of both internal and external training load data is recommended to fully appreciate the physical demands of squash training. During a training microcycle containing a variety of training sessions, interpreting internal or external metrics in isolation may underestimate or overestimate the training stress a player is experiencing.

Quantifying Training Demands of a 2-Week In-Season Squash Microcycle.

PURPOSE: To quantify the demands of specific on- and off-court sessions, using internal and external training load metrics, in elite squash. METHODS: A total of 15 professional squash players (11 males and 4 females) wore a 100-Hz triaxial accelerometer/global positioning system unit and heart rate monitor during on-court "Group," "Feeding," "Ghosting," "Matchplay," and off-court "Conditioning" sessions across a 2-week in-season microcycle. Comparisons of absolute training load (total values) and relative intensity (per minute) were made between sessions for internal (session rating of perceived exertion, differential rating of perceived exertion, TRIMP) and external (Playerload, very high-intensity movements [>3.5 m·s-2]) metrics. RESULTS: The Group sessions were the longest (79 [12] min), followed by Feeding (55 [15] min), Matchplay (46 [17] min), Conditioning (37 [9] min), and Ghosting (35 [6] min). Time >90% maximum heart rate was the lowest during Feeding (vs all others P < .05) but other sessions were not different (all P > .05). Relative Playerload during Conditioning (14.3 [3.3] arbitrary unit [a.u.] per min, all P < .05) was higher than Ghosting (7.5 [1.2] a.u./min) and Matchplay (6.9 [1.5] a.u./min), with no difference between these 2 sessions (P ≥ .999). Conditioning produced the highest Playerloads (519 [153] a.u., all P < .001), with the highest on-court Playerloads from Group (450 [94] a.u., all P < .001). The highest session rating of perceived exertion (all P < .001), Edward's TRIMP (all P < .001), and TEAM-TRIMP (all P < .019) occurred during the Group sessions. CONCLUSIONS: Squash Matchplay does not systematically produce the highest training intensities and loads. Group sessions provide the highest training loads for many internal and external parameters and, therefore, play a central role within the training process. These findings facilitate planning or adjustment of intensity, volume, and frequency of sessions to achieve desirable physical outcomes.

Regression Analysis of Perceived Stress among Elite Athletes from Changes in Diet, Routine and Well-Being: Effects of the COVID-19 Lockdown and "Bubble" Training Camps.

The COVID-19 pandemic has affected the lifestyles and training of elite athletes around the world. The detrimental effects of lockdown periods may vary among individuals, as well as among sports and sexes. This study investigated the changes in dietary habits, and the predictors of perceived stress during lockdown and a "bubble" training camp. This cross-sectional, online survey involved 76 elite and world-class athletes from six able-bodied sports and nine parasports, all of whom were involved in a 30-day "bubble" training camp. Questions were asked on socio-demographics, training routines and wellbeing, perceived stress, and dietary habits, pertaining to "normal" training (prelockdown), lockdown training, and "bubble" camp training periods. Changes in perceived stress were trivial to small during lockdown compared to "normal" training, and trivial to moderate during a "bubble" camp, compared to lockdown. Para-athletes, males, older athletes, less experienced athletes, married individuals, and specific ethnicities appeared to be more detrimentally affected (increased perceived stress) by lockdown. These negative experiences, however, were largely reversed during "bubble" camps. During lockdown, more athletes reported increased evening snack consumption (+8%), later meal-times (+6%), decreased fluid intake (-6%), and no breakfast (+7%). These changes were reversed during "bubble" camps (12-18% improvements). Sport classification accounted for 16% of the increased perceived stress (p = 0.001) during lockdown. Overall, socio-demographic factors, improvements in training routines, well-being, and dietary habits explained 28% of the decreased perceived stress during a "bubble" camp. In conclusion, better dietary habits, training routines and well-being have implications for reduced perceived stress. During lockdown, "bubble" camps may be beneficial, but this observation may be a case-by-case consideration, and short split "bubble" periods are recommended.

In-Season Repeated-Sprint Training in Hypoxia in International Field Hockey Players.

Repeated-sprint training in hypoxia (RSH) studies conducted "in-season" are scarce. This study investigated the effect of discontinuous, running-based RSH, on repeated-sprint treadmill performance in hypoxia in a team sport cohort, prior to international competition. Over a 6-week "in-season" period, 11 elite male players (Malaysia national team) completed eight multi-set RSH sessions on a non-motorized treadmill in a normobaric hypoxic chamber (FiO2 = 13.8%). Three testing sessions (Sessions 1, 5, and 8), involved three sets of 5 × 8-s sprints, with 52-s recovery between sprints and 4-5 min between sets. Training sessions (Sessions 2, 3, 4, 6, and 7) consisted of four to five sets of 4-5 × 8-s sprints. During testing sessions, maximum sprinting speed was recorded for each sprint with values averaged for each set. For each set, a peak speed and fatigue index were calculated. Data were compared using two-way repeated measures ANOVA (sessions × sets). Average speed per set increased between testing sessions (p = 0.001, η p 2 = 0.49), with higher values in Session 8 (25.1 ± 0.9 km.h-1, +4 ± 3%, p = 0.005), but not Session 5 (24.8 ± 1.0 km.h-1, +3 ± 3%, p = 0.405), vs. Session 1 (24.2 ± 1.5 km.h-1). Peak sprinting speed in each set also increased across testing sessions (p = 0.008, η p 2 = 0.382), with Session 8 (26.5 ± 1.1 km.h-1) higher than Session 5 (25.8 ± 1.0 km.h-1, +1 ± 4%, p = 0.06) and Session 1 (25.7 ± 1.5 km.h-1, +4 ± 4%, p = 0.034). Fatigue index differed between sessions (p = 0.04, η p 2 = 0.331, Session 1; -6.8 ± 4.8%, Session 5; -3.8 ± 2%, Session 8; -5.3 ± 2.6%). In international field hockey players, a 6-week in-season RSH program improved average and peak, repeated treadmill sprint speeds following eight, but not five sessions.