Warm-up is an efficient strategy to prevent diurnal variation of short-term maximal performance in young basketball players.

The objectives of this study were to investigate: 1) whether there were morning-to-evening differences in short-term maximal performance and 2) the impact of prolonged and specific warm-up on short-term maximal performance diurnal variations in young basketball players. Fifteen basketball players of both sexes (Male = 8; Female = 7; age: 14.4 ± 0.46 yr; weight: 64.7 ± 7.1 kg; height: 175.2 ± 6.6 cm; BMI: 21.1 ± 1.9 kg/m2) completed the following short-term maximal performance tests: CMJ with and without arm swing, Lane Agility Drill, Zig-Zag agility test with and without the ball, Sprint 20 m with and without the ball with the passage at 5 and 10 m. All tests were performed after the 15-min standard warm-up procedure (with static stretching) and/or 25-min specific warm-up (with prolonged running and dynamic stretching) in the morning and evening. Vertical jumping tests and all change-of-direction speed tests (with and without a ball) with superior responses were achieved in the evening after standard warm-up among all participants (p < 0.05). In contrast, superior short-term maximal performance was observed in the morning after prolonged and specific warm-up protocol (p < 0.05). It was concluded that specific and prolonged warm-up protocols are suitable strategy to prevent diurnal variation in short-term maximal performance in young basketball players.

Effects of High-Intensity Interval Training (HIIT) on Physical Performance in Female Team Sports: A Systematic Review.

BACKGROUND: There is limited information regarding adaptation of HIIT in female athletes which is important since the adaptation to HIIT may be different compared to male athletes. Therefore, the aim of this systematic review was to summarize the effects of HIIT on physical performance in female team sports athletes. METHODS: The following databases Google Scholar, PubMed, Web of Science, Cochrane Library, ProQuest and Science Direct were searched prior to September 2nd, 2022. The inclusion criteria were longitudinal studies written in English, elite, sub-elite or college female team sports participants, and HIIT intensity had to be at 80-100% maximal heart rate. There were no exclusion criteria regarding the age of the participants or their training experience. The primary outcome measures were maximal oxygen uptake (VO2max), repeated sprint ability (RSA), change of direction speed, speed, explosive strength and body composition. RESULTS: A total of 13 studies met the inclusion criteria, with a total of 230 participants. HIIT improved VO2max in five studies (ES from 0.19 to 1.08), while three studies showed improvement in their RSA (ES from 0.32 to 0.64). In addition, change of direction speed was improved in five studies (ES from 0.34 to 0.88), while speed improved in four studies (ES from 0.12 to 0.88). Explosive strength results varied (ES from 0.39 to 1.05), while in terms of body composition, the results were inconsistent through observed team sports. CONCLUSION: HIIT has significant effects on VO2max, RSA, change of direction speed, speed and explosive strength in female team sports, regardless of the competition level.

The effects of taurine ingestion on anaerobic and physiological performance in female rugby players.

The purpose of this study was to investigate the acute effect of low, moderate, or high doses of taurine on anaerobic and physiological performance in female rugby players. A total of 16 sub-elite female rugby athletes (21.3 ± 1.5 yr, 168.0 ± 4.9 cm, 62.1 ± 3.5 kg mean ± SD) participated in this research. Following familiarization, participants attended 4 successive tests separated by 72 h in a randomized, counter-balanced, crossover research design. Following an over night fast, participants completed a 5-min 60 Watt warm-up followed by a 30-s Wingate anaerobic test on a cycle ergometer after ingestion of either 2 g taurine (LOWTAU), 4 g (MODTAU), 6 g (HIGHTAU) or placebo (PLA) 1 h before the test. Peak (PP) and mean power (MP) along with heart rate (HR), rating of perceived exertion (RPE), capillary lactate and blood glucose were measured. LOWTAU did not affect PP, MP, HR, lactate and glucose compared to PLA (p > 0.05), while MODTAU improved MP and HIGHTAU improved PP and MP compared to PLA and LOWTAU (p < 0.05). MODTAU and HIGHTAU had little effect on HR, blood lactate and glucose (p > 0.05). A single dose of taurine (MODTAU or HIGHTAU) 1 h prior to competition or training would provide an ergogenic effect on subsequent power output.

Intermittent high-intensity exercise for pre- to established hypertension: A systematic review and meta-analysis.

OBJECTIVE: To determine the impact of intermittent high-intensity exercise training ([IHIE], including high-intensity interval training [HIIT] and recreational team sports [RTS]) on systolic (SBP) and diastolic blood pressure (DBP) in adults with pre- to established arterial hypertension. DATA SOURCES: MEDLINE, Cochrane Library, Embase, and SPORTDiscus. ELIGIBILITY CRITERIA: Randomized controlled trials (RCTs) comparing the impact of IHIE on BP versus a non-exercise control. DATA COLLECTION AND ANALYSIS: Two authors independently conducted all procedures. Mean differences were calculated using random-effects model. The certainty of the evidence was assessed with GRADE. RESULTS: Twenty-seven RCTs (18 HIIT and 9 RTS) were analyzed, with median duration of 12 weeks. Participants' (n = 946) median age was 46 years. Overall, IHIE decreased SBP (-3.29 mmHg; 95% CI: -5.19, -1.39) and DBP (-2.62 mmHg; 95% CI: -3.79, -1.44) compared to the control group. IHIE elicited higher decreases in office SBP and DBP of hypertensive subjects (SBP: -7.13 mmHg, [95% CI: -10.12, -4.15]; DBP: -5.81 mmHg, [95% CI: -7.94, -3.69]) than pre-hypertensive (SBP: -2.14 mmHg, [95% CI: -4.36, -0.08]; DBP: -1.83 mmHg, [95% CI: -2.99, -0.67]). No significant differences were found between HIIT (SBP: -2.12 mmHg, [95% CI: -4.78, -0.54]; DBP: -1.89 mmHg, [95% CI: -3.32, -0.48]) and RTS (SBP: -4.18 mmHg, [95% CI: -7.19, -2.43]; DBP: -4.04 mmHg, [95% CI: -6.00, -2.09]). These findings present low/very low certainty of evidence. No adverse cardiovascular events were reported. CONCLUSIONS: IHIE appears to be safe and to promote substantial decreases in BP, particularly in patients with hypertension. However, the certainty of evidence was low/very low. PROTOCOL: CRD42020163575.

Performance factors that negatively influence shooting efficiency in women's basketball.

The purpose of the present study was to examine the influence of selected factors (possession duration, game quarter, defensive pressure, shooting distance from the basket, and heart rate level) on shooting efficiency on Under-19 (U19) and senior level of women's basketball competition (second division). The analysis procedures included five U19 and six senior-level games, containing 224 and 252 shooting attempts, respectively. Binary logistic regression identified the opponent's defensive pressure and shooting distance from the basket as significant predictors of shooting efficiency in both categories. When defensive pressure was high, the chance for the missed shot was 3.5 (95% CI; 1.43-8.52) and 3.19 (95% CI; 1.4-7.26) times more likely than it was under the minimum defensive pressure for U19 and senior category, respectively. Shooting efficiency significantly decreased when the horizontal distance from the basket increased. In U19, a chance for a missed shot was 4.63 (95% CI; 2-10.712) and 5.15 (95% CI; 1.91-13.86) times higher for medium and long-distance (respectively), compared to short-range shooting. In the senior category, the chance for the missed shot was 3.9 (95% CI; 1.83-8.31) and 3.27 (95% CI; 1.43-7.52) times higher for medium and long-distance (respectively) when compared to a short distance. The possession duration, game quarter, and heart rate level were identified as insignificant predictors. Therefore, the aforementioned findings suggest that basketball players and coaches may benefit from designing training sessions where the defender puts pressure on the shooting player as in a real game situation and balanced the frequency of shooting from different distances from the basket.

Effect of home training during the COVID-19 lockdown on physical performance and perceptual responses of team-sport athletes: a mini-review.

This article aims to summarize the effects of home training performed during the COVID-19 lockdown on physical performance and perceptual responses among team-sport athletes. Studies with comparison of pre-post lockdown results of physical performance and perceptual responses were considered. A search was made in PubMed and SPORTDiscus databases. The PICO criteria were used for the keywords "athlete" AND "home-based training" AND "performance" OR "mental health", with their respective entry terms. The multistage process of selection followed the PRISMA 2020 recommendations. Of 586 records identified, 9 articles were available for the final process. Physical performance was evaluated for 8 studies with the VO2max change ranging from 5.7% to -9%; an increase in the duration of sprint test ranging from 0.4% to 36%; an increase of agility duration of 12.4%; a decrease in maximal repetition load of 2.9%; and changes in countermovement jump height ranging from -4.7% to +15.4% after home training. Regarding the perceptual responses, no significant changes in wellbeing and mental index and a significant decrease in motivation and perceived effort were reported during the home training in lockdown. Based on the articles selected, home training programmes performed by athletes from team sports during the COVID-19 lockdown presented inconsistent results in physical performance, decreasing by up to 36%, and maintaining the wellbeing and mental index, but with a significant drop in training motivation and perceived effort. Caution should be taken considering the small number of articles included in the study.

Recreational Football and Bone Health: A Systematic Review and Meta-analysis.

BACKGROUND: Recreational football is an intense, versatile form of exercise with multiple high- and odd-impact actions. Recreational football is therefore hypothesized to be suitable for bone modeling and bone health. OBJECTIVE: The aim of the present systematic review and meta-analysis was to evaluate the effects of recreational football on bone mineral density (BMD), bone mineral content (BMC) and bone turnover markers (BTM). DESIGN: Systematic review and meta-analysis. DATA SOURCES: MEDLINE, PubMed, SPORTDiscus, Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Google Scholar were searched prior to September 2021. A manual database search was also performed using the following key terms, either singly or in combination: recreational football/soccer, street football/soccer, recreational small-sided games, effect, influence, impact, bone turnover markers, bone mineral density, bone turnover marker, bone health, osteogenesis, CTX, osteocalcin, P1NP. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Randomised and matched controlled trials with participants allocated to a recreational football group or any other type of training intervention or passive control group were included. The primary outcome measures were total BMD, lower limb BMD, total BMC, lower limb BMC, osteocalcin, procollagen type 1N-terminal propeptide (P1NP) and collagen type 1 cross-linked C-telopeptide (CTX). A total of 17 papers met the inclusion criteria and were included. STATISTICAL ANALYSIS: Comprehensive Meta-analysis V.2 software (Biostat, Englewood, New Jersey, USA) was used for the meta-analyses. RISK OF BIAS: Agreement between the two reviewers was assessed using RoB2 tool and k statistics for full-text screening and rating of relevance and risk of bias. The k agreement rate between reviewers was k = 0.92. RESULTS: The football interventions included were based on studies having a duration of 12-64 weeks with one 5-year follow-up study and with a training frequency of 1-3 sessions/wk. Training sessions were 45-60 min sessions of 3v3 - 7v7 small-sided games. The subjects covered an age span from 9 to 73 years. Five studies examined recreational football effects in females, nine studies in males and three studies included both sexes. Recreational football training produced a statistically significant effect (mean difference = 0.02 g/cm2, 95% confidence interval: 0.00-0.03, P = 0.02) on lower limb BMD and negligible effects for total BMD compared to no-exercise controls. The recreational football effects on total and lower limb BMC, when compared to both no-exercise controls and exercise controls, were negligible. A moderate to large significant increase in osteocalcin, P1NP and CTX was observed for recreational football compared to both no-exercise controls and exercise controls. CONCLUSION: In conclusion, recreational football training regimes lasting 12-64 weeks have a large osteogenic impact on bone turnover markers in comparison with no-exercise controls as well as exercise controls, and beneficial effects on lower limb BMD compared to no-exercise controls. Short and medium duration recreational football interventions have negligible effects on whole-body BMD and BMC (total and lower limb), with magnitudes similar to those of other exercise modes.

The muscle contractile properties in female soccer players: inter-limb comparison using tensiomyography.

OBJECTIVE: The present study aimed to: i) determine the contractile properties of the major lower limb muscles in female soccer players using tensiomyography; ii) investigate inter-limb differences; and iii) compare inter-limb differences between different selections and playing positions. METHODS: A total of 52 female soccer players (A team; U19 and U17) were recruited. The vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), gastrocnemius medialis (GM), lateralis (GL) and tibialis anterior (TA) of both lower limbs were evaluated. RESULTS: When the entire sample was assessed regardless of selection or playing position, there were significant inter-limb differences in all measured muscles except BF. Compared to the non-dominant limb, the dominant limb had higher delay time in VL (p=0.008), while showing lower values in VM (p=0.023), GL (p=0.043) and GM (p=0.006). Contraction time was lower in the RF of the dominant limb (p=0.005) and VM (p=0.047), while showing higher values in VL (p=0.036) and TA (p<0.001) as compared to the non-dominant limb. CONCLUSION: Given the differences found between the limbs in the whole sample studied, it is necessary to examine both limbs to gather a more in-depth understanding of underlying mechanisms related to neuromuscular functions in female soccer players. LEVEL OF EVIDENCE: Prognostic study, Level II.

Acute caffeine supplementation improves jumping, sprinting, and change-of-direction performance in basketball players when ingested in the morning but not evening.

This study compared the effects of acute caffeine supplementation (3 mg/kg) administered in the morning and evening on performance-related variables in basketball players. Eleven, national-level, adolescent male basketball players underwent field-based fitness testing on four occasions: morning (10:00) with caffeine ingestion (AMCAFF), morning (10:00) with placebo ingestion (AMPLAC), evening (21:00) with caffeine ingestion (PMCAFF), and evening (21:00) with placebo ingestion (PMPLAC). Fitness testing included of a countermovement jump without arm swing (CMJ), CMJ with arm swing (CMJAS), squat jump (SJ), Lane Agility Drill (LAD), 20-m linear sprint, and Suicide Run with (SRD) and without dribbling (SR). Data were analysed using two-way repeated measures analyses of variance and paired t-tests, with effect sizes (ES) also determined for all pairwise comparisons. Follow-up t-test comparisons revealed that AMCAFF produced small-moderate, significant (p<0.001), improvements in CMJ (ES = 0.51), CMJAS (ES = 0.40), SJ (ES = 0.51), and SR (ES = -0.45) compared to AMPLAC. AMCAFF also produced a moderate, significantly (p<0.001) faster LAD (ES = -0.61) compared to PMCAFF. PMPLAC demonstrated small-moderate, significant (p<0.05) improvements in CMJ (ES = 0.43), CMJAS (ES = 0.48), and 20-m sprint (ES = -0.63) compared to AMPLAC. In contrast, AMPLAC resulted in large, significantly (p<0.001), faster SRD (ES = -1.46) and SR (ES = -1.59) compared to PMPLAC. Given the ergogenic effects of caffeine during basketball-specific fitness tests appear to be influenced by time of ingestion, basketball practitioners should consider administering caffeine only to players in the morning to improve vertical jump, sprinting, and change-of-direction performance, with no beneficial effects observed with caffeine ingestion in the evening.Highlights The effect of caffeine supplementation on basketball-specific performance related variables were mediated by ingestion time in elite, adolescent basketball players.AMCAFF produced small-moderate improvements in vertical jump, change-of-direction, 20-m linear sprint, and repeated-sprint performance compared to AMPLAC while PMCAFF produced trivial differences in each performance-related variable compared to PMPLAC.Comparisons between ingestion times in the placebo condition revealed vertical jump height and 20-m sprint speed were impaired in the morning compared to the evening, but these time-dependent differences were eliminated when caffeine was consumed in the morning.Basketball practitioners should consider administering caffeine only to players in the morning to improve vertical jump, sprinting, and change-of-direction performance, with no beneficial effects observed with caffeine ingestion in the evening.

The Qatar 2022 World Cup warm-up: Football goal-scoring evolution in the last 14 FIFA World Cups (1966-2018).

The aim of this study was to elucidate pattern of attacking actions leading up to goal scoring during the 14 FIFA World Cups from 1966 to 2018. The study analysed 1881 goals scored during a total of 732 matches. We employed observational methodology design. Before goal analysis began, it was developed the observing protocol in which data related to selected variables, by system of notation, was entered after reviewing each individual goal scoring action. The analysis of all video material was carried out independently by four experienced examiners (three of them are Ph.D in sports science and one is Ph.D. candidate in sports science with at least 7 years of coaching and experience as analyst in football). The inter-and intra-observer reliability presented good level of agreement. The kappa values ranged from 0.82 (goal scoring through open play) to 1.00 (action leading up to goal), showing a very high agreement for all performance variables. Interclass correlation was very high (ICC = 0.966, 95% upper and lower confidence intervals were between 0.933 and 1.00). A statistically significant trend (p < 0.05) from 1966 to 2018 was identified towards a higher relative frequency of goals scored from set play and collective actions from open play. The Chi-square did not reveal significant differences in the frequency of goal scoring patterns and goal-scoring zones. The results also revealed that the majority of goals were scored between the 76th and 90th minutes of a match (22.7%), from open play (70.5%), inside the penalty area (54.7%), one touch finishing (62.5%), and collective attacks in open play (55.8%). These findings may provide a possible strategic direction for improving goal-scoring performance in football, as well as practical implementation in World Cup tournament preparation.

Change of Direction Deficit: A Promising Method to Measure a Change of Direction Ability in Adolescent Basketball Players.

The aims of this study were to determine the relationship between vertical jumping performance, linear speed, change of direction speed (CODs) time and the COD deficit (CODD) in adolescent basketball players and to analyze the CODD between faster and slower players based on linear speed performance. Thirty-eight male basketball players (age: 15.47 ± 0.51 years; body height: 185.19 ± 5.67 cm; body mass: 71.87 ± 7.29 kg) completed countermovement jumps (CMJ) with and without an arm swing, squat jumps (SJs), linear sprints at 20 m with split times at 5 and 10 m, the pro-agility test and the zig-zag tests. Furthermore, the CODD was calculated as the difference between the 20 m linear speed result and CODs time in both COD tests. Pearson and Spearman analyses were used to determine the correlations between power-speed-related variables and the CODD. Moreover, independent t-tests and Cohen's d effect size (ES) were used to analyze the differences between the faster and slower players in the CODD. Moderate to strong significant negative correlations were observed between the CODD in the pro-agility test and linear speed at 5 m, 10 m, and 20 m (r = -0.55 to -0.46), while moderate negative significant correlation was found between the zig-zag CODD and SJs (r = -0.37) as well as small positive significant correlation between the CODD in the zig-zag test and the eccentric utilization ratio (EUR) (r = 0.23). Additionally, faster basketball players displayed significantly higher CODD values performing the pro-agility test. In summary, these findings underline the complexity of COD performance and the importance of remodeling traditional training programs in basketball players.

Effects of repeated sprint training in hypoxia on physical performance among athletes: a systematic review / Efectos del entrenamiento de velocidad repetida en hipoxia sobre el rendimiento físico entre atletas: una revisión sistemática

SUMMARY: Repeated sprint training in hypoxia (RSH) represents an innovative method in the process of development and improvement of physical performance among athletes. However, there is less scientific data on this topic. The purpose of this systematic review was to investigate the effect of RSH method on motor abilities and performance among athletes, obtain new information, and expand the already known conclusions. The data search was performed of 4 electronic databases for the years 2000-2021 May as follows: Google Scholar, PubMed, Web of Science, and ResearchGate. This search with English language restriction was made by using the following terms, individually/combination: "repeated sprint ability", "hypoxia", "effects", "physical performance", "VO2max" 844 studies were indentified, and 14 studies were selected (11 male studies, 1 female study, 2 both sexes). Results of this systematic review, a total sample size of 347 athletes (40 females and 307 males, aged 15.3 ± 0.5 - 35 ± 7 years), showed that RSH was an effective training method in improving all monitored variables (i.e. RSAmax, VO2max). However, it should be noted that major improvements were observed mainly in repeated sprint ability (RSA) tests, and less in aerobic tests (i.e. Wingate and Yo-Yo). In conclusion, based on current scientific studies, RSH is more effective method to improve the physical performance among athletes compared to repeated sprint training in normoxia (RSN). This study suggested that the RSH has a positive effect on the monitored variables in physical performance tests especially related to RSA.

RESUMEN: El entrenamiento de velocidad repetida en hipoxia (RSH) representa un método innovador en el proceso de desarrollo y mejora del rendimiento físico entre los deportistas. Sin embargo, existen pocos datos científicos sobre este tema. El propósito de esta revisión sistemática fue investigar el efecto del método RSH sobre las habilidades motoras y el rendimiento de los atletas, obtener nueva información y ampliar las conclusiones ya conocidas. La búsqueda de datos se realizó en 4 bases de datos electrónicas: Google Scholar, PubMed, Web of Science e Research Gate para los años 2000- a mayo de 2021. Esta búsqueda se realizó en artículos en idioma inglés mediante el uso de los siguientes términos, individualmente / combinación: "capacidad de sprint repetido", "hipoxia", "efectos", "rendimiento físico" y "VO2max" Se identificaron 844 estudios y se seleccionaron 14 de ellos (11 estudios realizados en hombres, un estudio realizado en mujeres y dos estudios realizados en am- bos sexos). Los resultados mostraron, un tamaño muestral total de 347 atletas (40 mujeres y 307 hombres, de 15,3 ± 0,5 - 35 ± 7 años). Se observó que la RSH fue un método de entrenamiento eficaz para mejorar todas las variables monitorizadas (es decir, RSAmax y VO2max). Sin embargo, se debe tener en consideración que se observaron mejoras importantes, principalmente, en las pruebas de capacidad de sprint repetido (RSA), y menos en las pruebas aeróbicas (es decir, Wingate y Yo-Yo). En conclusión, según los estudios científicos actuales, la RSH es un método más eficaz para mejorar el rendimiento físico entre los atletas en comparación con el entrenamiento de velocidad repetida en normoxia (RSN). Este estudio sugirió que la RSH tiene un efecto positivo sobre las variables monitoreadas en las pruebas de rendimiento físico especialmente relacionadas con RSA.

Effects of 12-week aquatic exercises on gross motor function, swimming skills and walking ability in children with cerebral palsy.

BACKGROUND: Cerebral palsy (CP) is the most common cause of physical disability in childhood defined as a group of permanent disorders of movement. The aim of this study was to determine the effects of 12-week aquatic exercise program on gross motor function, swimming skills, and walking ability in children with cerebral palsy. METHODS: Eighteen children (Mean ± SD age: 12.3 ± 3 years) with cerebral palsy classified at Levels I, II and III on the Gross Motor Function Classification System were allocated to one group, where the first 12 weeks were a control period while another 12 weeks were an experimental period. The participants underwent the same battery of tests focusing gross motor function, swimming skills, and walking ability on three occasions. RESULTS: Control period was stable with no significant changes in any of measurements. After the 12-week experimental program, a statistically significant improvement was determined in gross motor function (p=0.005), swimming skills (p=0.000), walking endurance and walking (p=0.000). No significant differences (p>0.05) were observed for walking efficiency. CONCLUSIONS: The 12-week aquatic exercise program (3/week, 60 minutes), combining Halliwick method, swimming and walking activities may improve the gross motor function, swimming skills, walking endurance and velocity in ambulatory children with cerebral palsy.

The Aging Muscle in Experimental Bed Rest: A Systematic Review and Meta-Analysis.

Background: Maintaining skeletal muscle mass and function in aging is crucial for preserving the quality of life and health. An experimental bed rest (BR) protocol is a suitable model to explore muscle decline on aging during inactivity. Objective: The purpose of this systematic review and meta-analysis was, therefore, to carry out an up-to-date evaluation of bed rest, with a specific focus on the magnitude of effects on muscle mass, strength, power, and functional capacity changes as well as the mechanisms, molecules, and pathways involved in muscle decay. Design: This was a systematic review and meta-analysis study. Data sources: We used PubMed, Medline; Web of Science, Google Scholar, and the Cochrane library, all of which were searched prior to April 23, 2020. A manual search was performed to cover bed rest experimental protocols using the following key terms, either singly or in combination: "Elderly Bed rest," "Older Bed rest," "Old Bed rest," "Aging Bed rest," "Aging Bed rest," "Bed-rest," and "Bedrest". Eligibility criteria for selecting studies: The inclusion criteria were divided into four sections: type of study, participants, interventions, and outcome measures. The primary outcome measures were: body mass index, fat mass, fat-free mass, leg lean mass, cross-sectional area, knee extension power, cytokine pattern, IGF signaling biomarkers, FOXO signaling biomarkers, mitochondrial modulation biomarkers, and muscle protein kinetics biomarkers. Results: A total of 25 studies were included in the qualitative synthesis, while 17 of them were included in the meta-analysis. In total, 118 healthy elderly volunteers underwent 5-, 7-, 10-, or 14-days of BR and provided a brief sketch on the possible mechanisms involved. In the very early phase of BR, important changes occurred in the skeletal muscle, with significant loss of performance associated with a lesser grade reduction of the total body and muscle mass. Meta-analysis of the effect of bed rest on total body mass was determined to be small but statistically significant (ES = -0.45, 95% CI: -0.72 to -0.19, P < 0.001). Moderate, statistically significant effects were observed for total lean body mass (ES = -0.67, 95% CI: -0.95 to -0.40, P < 0.001) after bed rest intervention. Overall, total lean body mass was decreased by 1.5 kg, while there was no relationship between bed rest duration and outcomes (Z = 0.423, p = 672). The meta-analyzed effect showed that bed rest produced large, statistically significant, effects (ES = -1.06, 95% CI: -1.37 to -0.75, P < 0.001) in terms of the knee extension power. Knee extension power was decreased by 14.65 N/s. In contrast, to other measures, meta-regression showed a significant relationship between bed rest duration and knee extension power (Z = 4.219, p < 0.001). Moderate, statistically significant, effects were observed after bed rest intervention for leg muscle mass in both old (ES = -0.68, 95% CI: -0.96 to -0.40, P < 0.001) and young (ES = -0.51, 95% CI: -0.80 to -0.22, P < 0.001) adults. However, the magnitude of change was higher in older (MD = -0.86 kg) compared to younger (MD = -0.24 kg) adults. Conclusion: Experimental BR is a suitable model to explore the detrimental effects of inactivity in young adults, old adults, and hospitalized people. Changes in muscle mass and function are the two most investigated variables, and they allow for a consistent trend in the BR-induced changes. Mechanisms underlying the greater loss of muscle mass and function in aging, following inactivity, need to be thoroughly investigated.

Danger zone assessment in small-sided recreational football: providing data for consideration in relation to COVID-19 transmission.

During the COVID-19 pandemic, physical inactivity has increased, and a wide range of sporting activities locked down, with possible long-term implications for public health. Football is the most popular sport worldwide, and recreational football training leads to broad-spectrum health effects. Football is, however, deemed a contact sport with frequent close contact important to consider during COVID-19 pandemic. OBJECTIVES: This study investigated time spent with close contact (danger zone (DZ) within 1.5 m), number of contacts and time per contact, and compared game formats in recreational small-sided football games for young and adult male football players. METHODS: Movement analyses were performed on 10 Hz Global Positioning System (GPS) data collected during various small-sided football games prior to the COVID-19 outbreak. RESULTS: Time spent in the DZ was 4.3-7.9 s/h per per cent infected players, corresponding to 34.3-114.8 s/h if one player was infected. Number of contacts with one infected player was 23.5-87.7 per hour, with an average contact time of 1.1-1.4 s, and a total number of contacts of 311-691 per hour with all players. 53%-65% of all contacts were shorter than 1 s and 77%-85% shorter than 2 s. Trivial to small effects were found for number of participants and area per player, whereas standard of play and playing with/without boards had no effect. CONCLUSION: This study demonstrated that during small-sided football limited time is spent within DZ and that player contacts are brief. Recreational football may therefore more appropriately be deemed as sporting activity with brief, sporadic contact.

Aerobic Capacity According to Playing Role and Position in Elite Female Basketball Players Using Laboratory and Field Tests.

PURPOSE: To compare the aerobic capacity of elite female basketball players between playing roles and positions determined using maximal laboratory and field tests. METHODS: Elite female basketball players from the National Croatian League were grouped according to playing role (starter: n = 8; bench: n = 12) and position (backcourt: n = 11; frontcourt: n = 9). All 20 players completed 2 maximal exercise tests in a crossover fashion 7 days apart. First, the players underwent a laboratory-based continuous running treadmill test with metabolic measurement to determine their peak oxygen uptake (VO2peak). The players then completed a maximal field-based 30-15 Intermittent Fitness Test (30-15 IFT) to estimate VO2peak. The VO2peak was compared using multiple linear regression analysis with bootstrap standard errors and playing role and position as predictors. RESULTS: During both tests, starters attained a significantly higher VO2peak than bench players (continuous running treadmill: 47.4 [5.2] vs 44.7 [3.5] mL·kg-1·min-1, P = .05, moderate; 30-15 IFT: 44.9 [2.1] vs 41.9 [1.7] mL·kg-1·min-1, P < .001, large), and backcourt players attained a significantly higher VO2peak than frontcourt players (continuous running treadmill: 48.1 [3.8] vs 43.0 [3.3] mL·kg-1·min-1, P < .001, large; 30-15 IFT: 44.2 [2.2] vs 41.8 [2.0] mL·kg-1·min-1, P < .001, moderate). CONCLUSIONS: Starters (vs bench players) and guards (vs forwards and centers) possess a higher VO2peak irrespective of using laboratory or field tests. These data highlight the role- and position-specific importance of aerobic fitness to inform testing, training, and recovery practices in elite female basketball.

The Association Between Level of Physical Activity and Body Mass Index, and Quality of Life Among Elderly Women.

The process of aging leads to changes in functional abilities, fitness levels, level of physical activity, and body mass index (BMI), all of which causes changes in the quality of life. The current study aims to determine the association between the level of physical activity (PA) and BMI, and quality of life (QoL) among elderly women. The total sample numbered 156 women, with an average age of 67.7 ± 5.6 years. To determine the level of physical activity, the self-reported International Physical Activity Questionnaire Long Form (IPAQ-LF), was used. To calculate the values of the BMI, the standard procedure recommended by the World Health Organization was used. Quality of life was evaluated using the short form of the WHOQOL-BREF questionnaire designed by the World Health Organization. All the data were processed using the statistical package for data analysis SPSS 20.0. Pearson's correlation analysis shows statistically significant relations at the level of p < 0.01 between PA and Physical health in Housework = 0.36, Leisure time PA = 0.27, Walking = 0.24, Moderate PA 0.43, Total PA = 0.43, while the correlations between the variables at the significance level of p < 0.05 were determined in PA in transportation = 0.19 and High-intensity PA = 0.16. Multiple linear regression analysis of different levels of PA as independent variables on individual domains of QoL shows that there is an association of PA and Physical health (Sig = 0.000), more precisely, Total PA is statistically the most closely related to Physical health (Sig = 0.000), and then follows PA at work and Social relations (Sig = 0.036). Similar results were obtained when BMI is added to model A. In contrast to model A, model B shows a statistically significant association between PA and BMI with the environmental domain of QoL (Sig = 0.001). The results of the current study indicate that high- and moderate-intensity physical activity both have benefits for physical health, whereas moderate PA showed higher significance levels. Results also show that elderly women with higher BMI values achieve better results in the environmental domain of QoL.

Individualized and Fixed Thresholds to Demarcate PlayerLoad Intensity Zones Produce Different Outcomes.

ABSTRACT: Scanlan, AT, Fox, JL, Milanovic, Z, Stojanovic, E, Stanton, R, and Dalbo, VJ. Individualized and fixed thresholds to demarcate PlayerLoad intensity zones produce different outcomes. J Strength Cond Res 35(7): 2046-2052, 2021-Individualized approaches to derive intensity zones are yet to be examined using microsensor metrics in basketball. The purpose of this study was to quantify and compare the time spent in different PlayerLoad intensity zones using individualized and fixed approaches during basketball training. Thirteen semiprofessional, male basketball players were monitored across the preparatory training phase. Microsensors recorded the time spent in 6 PlayerLoad intensity zones using individualized and fixed approaches. Individualized zones were calculated relative to the peak instantaneous PlayerLoad response observed in each player across training. Fixed zones were determined following predefined cut-points set in proprietary software. The majority of training time was spent in zones 1-2 (98-99%), with a low proportion of time detected in zones 3-6 (1-2%) across approaches. The fixed approach produced greater training time in zones 2 (11.9 ± 1.2 vs. 9.3 ± 2.4 minutes; very likely large) and 3 (1.7 ± 0.8 vs. 0.8 ± 0.9 minutes; very likely moderate), was an unclear small increase in time spent in zone 1 were apparent using individualized thresholds (76.5 ± 11.2 vs. 72.9 ± 9.6 minutes). Almost certain similar time was spent in zones 4-6 across approaches. Individual analyses showed deviations across players; however, fixed PlayerLoad thresholds produced higher training time in zones 2 (moderate to very large), 3 (moderate to very large), 4 (moderate to large), and 5 (moderate) than the individualized approach in most players. Variations in outcomes between individualized and fixed approaches must be considered when quantifying the time spent working in PlayerLoad intensity zones.

Power-Related Determinants of Modified Agility T-test Performance in Male Adolescent Basketball Players.

ABSTRACT: Scanlan, AT, Wen, N, Pyne, DB, Stojanovic, E, Milanovic, Z, Conte, D, Vaquera, A, and Dalbo, VJ. Power-related determinants of Modified Agility T-test performance in male adolescent basketball players. J Strength Cond Res 35(8): 2248-2254, 2021-Although the Modified Agility T-test (MAT) has been advocated for assessing change-of-direction performance in basketball, the power-related attributes emphasized during the test are unknown. Therefore, the aim of this study was to identify the power-related determinants of the MAT in basketball players. A cross-sectional, descriptive research design was used whereby national- and state-level male adolescent basketball players (n = 24; 17.3 ± 0.5 years) completed a battery of power-related performance tests. The tests administered included the MAT, isometric midthigh pull, 10-m sprint, countermovement jump, 1-step vertical jump, standing long jump, and repeated lateral bound. Associations between performance during the MAT and other tests were quantified, and performance in each test was compared between faster (>50th percentile) and slower (<50th percentile) players in the MAT. The MAT exhibited large correlations (p < 0.05) with standing long jump distance (r = -0.67, R2 = 45%), countermovement jump relative peak force (r = -0.63, R2 = 39%), isometric midthigh pull relative peak force (r = -0.55, R2 = 30%), and 10-m sprint time (r = 0.53, R2 = 28%). The faster group performed better (p < 0.05) during the standing long jump (mean difference; ±90% confidence limits: 0.16; ±0.12 m) and produced greater (p < 0.05) relative peak force during the isometric midthigh pull (2.5; ±2.3 N·kg-1) and countermovement jump (2.1; ±1.8 N·kg-1) than the slower group. The MAT complements other power-related tests used in basketball and stresses basketball-specific, power-related attributes in various movement planes. These data can inform training and testing approaches to optimize change-of-direction performance in basketball.

Recreational Basketball Small-Sided Games Elicit High-Intensity Exercise With Low Perceptual Demand.

ABSTRACT: Stojanovic, E, Stojiljkovic, N, Stankovic, R, Scanlan, AT, Dalbo, VJ, and Milanovic, Z. Recreational basketball small-sided games elicit high-intensity exercise with low perceptual demand. J Strength Cond Res 35(11): 3151-3157, 2021-The purpose of this study was to describe and compare the internal and external load imposed on players during 1-a-side, 2-a-side, and 3-a-side recreational basketball small-sided games (SSGs). Twelve recreationally active, male college students were monitored across 10 minutes of 1-a-side, 2-a-side, and 3-a-side basketball SSG. Internal load variables included continuous measurement of heart rate (HR) responses, as well as rating of perceived exertion (RPE) and blood lactate concentration (BLa), after each game. External load variables included measurement of the total distance covered as well as the frequency of accelerations and decelerations. Blood lactate concentration and RPE were moderately (p < 0.05) greater in 1-a-side SSG than 3-a-side SSG. Total accelerations and decelerations were higher in 1-a-side and 2-a-side SSG compared with 3-a-side SSG (p < 0.05, moderate-large). All SSG formats resulted in players spending more time (p < 0.05, moderate-large) at higher HR intensities (81-100% HRmax) than lower intensities (≤80% HRmax). Furthermore, players covered greater distances (p < 0.05, large-very large) at lower intensities (0-12 km·h-1) and completed more accelerations and decelerations (p < 0.05, large-very large) at lower intensities (<2 m·s-2) than at higher intensities across SSG formats. Basketball SSG consisting of 1-3 players elicits an intermittent activity profile, promoting the extensive utilization of anaerobic and aerobic metabolism pathways, which potentially can lead to marked improvements in cardiovascular and musculoskeletal fitness in the general population when administered in recreational settings. Moreover, recreational basketball SSG with only 1 player per team elicits higher BLa, RPE, distances covered at low speeds as well as acceleration and deceleration volumes than SSG with 3 players per team.