The Associations between Evacuation Movements and Children's Physiological Demands Analyzed via Wearable-Based Sensors.

During fire evacuations, crawling is recommended to prevent harm from toxic smoke and to access more breathable air. Few studies have evaluated the physiological burden of crawling, especially for children. The method of using wearable sensors to collect data (e.g., electrodermal activity, EDA; skin temperature, SKT) was used to evaluate the effects of different locomotive postures on children's velocity and physiological demands. Twenty-eight (28) children (13 boys and 15 girls), aged 4 to 6 years old, traveled up to 22.0 m in different postures: Upright walking (UW), stoop walking (SW), knee and hand crawling (KHC). The results showed that: (1) Gender and age had significant impacts on children's velocity (p < 0.05): Boys were always faster than girls in any of the three postures and the older the child, the faster the velocity for KHC. (2) Physiological results demonstrated that KHC was more physically demanding than bipedal walking, represented by higher scores of the EDA and SKT indicators, similar to the findings of adults. (3) Gender and age had significant impacts on children's physiological demands (p < 0.05). The physiological demands were greater for boys than girls. In addition, the higher the age, the less physiological demands he/she needs. Overall, the findings suggest that children are unnecessarily required to choose crawling precisely as adults as the best posture to respond to emergency scenarios. In a severe fire, stoop walking is suggested, as there is more respired air and children could move quickly and avoid overworking physiological burdens. The results of this study are expected to be considered in the evaluation of current evacuation recommendations and for the safety guide of preparedness to improve the effectiveness of risk reduction for children.

Changes in salivary markers during basketball long-term and short-term training periods: a systematic review.

Changes in salivary markers have been largely assessed during different modalities of long-term and short-term basketball training across different basketball populations. The aim of this paper was to systematically review the literature assessing changes in salivary markers in basketball following long-term and short-term training periods. An electronic database search of articles published until October 2020 was completed in PubMed, SPORTDiscus, Scopus and Web of Science. Studies were then screened and selected using pre-defined selection criteria with 1080 articles identified. After removing 690 duplicates, 390 articles were included for screening, which revealed 15 articles that met the inclusion criteria. The main findings revealed no changes in testosterone (T), cortisol (C) or their ratio (T:C), while contrasting results were found in immunoglobulin A (IgA) and total protein (TP) levels across long-term periodized training periods in different basketball populations. The analysis of short-term training periods showed that strength-hypertrophy training induced higher C levels compared to a non-exercising day, one-power training and one-endurance training session in female basketball players, while no changes were evident for T and IgA. Moreover, the analysis of salivary markers in response to small-sided games (SSGs) documented a large-to-moderate increase in alpha-amylase (AA) from pre- to post-SSG and inconsistent results of C and T across differently designed SSGs. The current results provide a detailed description of salivary marker changes in response to different basketball long- and short-term training periods, which can help practitioners in designing sound training programmes to optimize players' fitness and health status across different phases of the season.

The effect of basketball matches on salivary markers: a systematic review.

The aim of this paper was to synthesize the findings on salivary marker responses to the different basketball match typologies. An electronic database search of articles published until October 2020 was performed in PubMed, SPORTDiscus, Scopus and Web of Science. Studies were then screened using pre-defined selection criteria and a subsequent assessment of methodological quality was conducted. Articles matching the selection criteria and methodological quality were included in the systematic review. The electronic database search produced 696 articles. After removing 505 duplicates, 191 articles were included for screening. Screening led to 10 articles that met the inclusion criteria. The main findings revealed that playing a basketball match induced a highly stressful condition reflected by increased post-match cortisol levels regardless of season phase (i.e. regular vs. semi-final vs. final matches), match outcome (i.e. winning vs. losing matches) and location (i.e. home vs. away). Different results were found for testosterone, which showed inconsistent outcomes when measured before and after matches. However, an effect of match location on testosterone levels was observed, with higher concentrations before home matches compared to away matches. Finally, playing basketball matches led to an increase in levels of alpha-amylase, a decrease in interleukin-21 and no changes in immunoglobulin A, total protein and brain-derived-neurotrophic factor. The current results provide a detailed description of salivary markers changes in response to different basketball matches, which can help practitioners to have a better understanding of the basketball performance profile.

Treadmill load carriage overestimates energy expenditure of overground load carriage.

This study compared physiological and biomechanical responses between treadmill and overground load carriage. Thirty adults completed six 10-minute walking trials across three loads (0, 20, and 40% body mass) and two surfaces (treadmill and overground). Relative oxygen consumption was significantly greater on the treadmill for 20% (1.54 ± 0.20 mL⋅kg-1⋅min-1) and 40% loads (1.08 ± 0.20 mL⋅kg-1⋅min-1). All other physiological and perceptual responses were significantly higher in the treadmill condition and with increases in load. Stance time was longer (0%: 0.05 s; 20%: 0.02 s, 40%: 0.05 s, p < 0.001) and cadence was lower (0%: 1 step·min-1; 20%: 2 steps·min-1; 40%: 3 steps·min-1, p < 0.05) on the treadmill. Peak lower limb joint angles were similar between surfaces except for ankle plantar flexion, which was 8˚ greater on the treadmill. The physiological responses to treadmill-based load carriage are generally not transferable to overground load carriage and caution must be taken when conducting treadmill-based load carriage research to inform operational-based scenarios. Practitioner Summary: Literature is limited when comparing the physiological and biomechanical responses to treadmill and overground load carriage. Using a repeated measures design, it was shown that although walking kinematics are generally similar between surfaces, there was a greater physiological demand while carrying a load on a treadmill when compared with overground. Abbreviations: BM: body mass; e.g: for example; HR: heart rate; HRmax: heart rate maximum; Hz: hertz; kg: kilograms; km·h-1: kilometres per hour; L⋅min-1: litres per minute; m: metres; MD: mean difference; mL·kg-1·min-1: millilitres per kilogram per minute; mL⋅min-1: millilitres per minute; η2p: partial-eta squared; OG: overground; RPE: rating of perceived exertion; s: seconds; SD: standard deviation; SE: standard error; steps·min-1: steps per minute; TM: treadmill; V̇CO2: volume of carbon dioxide; V̇E: ventilation; V̇O2: volume of oxygen; V̇O2max: maximum volume of oxygen; y: years.

No physiological or biomechanical sex-by-load interactions during treadmill-based load carriage.

This study investigated whether physiological demand or gait mechanics differ between sexes during treadmill load carriage. Female (n = 15) and male (n = 15) military recruit-type participants with no load carriage experience completed three 10-minute walking trials at a self-selected speed with increasing relative body-borne loads (0%, 20%, and 40% body weight). A range of cardiorespiratory, perceptual and biomechanical variables were measured. Self-selected walking speed was similar between sexes (4.6-4.8 km·h-1, p > .05) and there were no significant sex-by-load interactions for any variables. Absolute VO2 and VCO2 were greater in males (difference 175-178 mL·min-1, p < .001), however, when relative to body mass, VO2 was similar between sexes (p > .05). Across all loads, cadence was 7 ± 2 steps·min-1 faster (p = .004) and stance time was 0.06 ± 0.02 s shorter (p = .013) in females. Increasing load resulted in greater physiological demand, cadence, % stance time, and step length (p < .05). Practitioner summary: Literature comparing physiological and biomechanical variables between sexes during load carriage is scarce. Physiological and biomechanical sex differences were limited to relative measures associated with physical size (height and mass). Future research may pool male and female participants when conducting trials up to ten minutes in length. Abbreviations: BW: body weight; COM: centre of mass; HR: heart rate; HRmax: maximum heart rate; RER: respiratory exchange ratio; RPE: rating of perceived exertion; VCO2: volume of carbon dioxide; VE: ventilation; VO2: volume of oxygen; VO2max: maximum volume of oxygen.

How to regulate the acute physiological response to "aerobic" high-intensity interval exercise.

The acute physiological processes during "aerobic" high-intensity interval exercise (HIIE) and their regulation are inadequately studied. The main goal of this study was to investigate the acute metabolic and cardiorespiratory response to long and short HIIE compared to continuous exercise (CE) as well as its regulation and predictability. Six healthy well-trained sport students (5 males, 1 female; age: 25.7 ± 3.1 years; height: 1.80 ± 0.04 m; weight: 76.7 ± 6.4 kg; VO2max: 4.33 ± 0.7 l·min(-1)) performed a maximal incremental exercise test (IET) and subsequently three different exercise sessions matched for mean load (Pmean) and exercise duration (28 min): 1) long HIIE with submaximal peak workloads (Ppeak = power output at 95 % of maximum heart rate), peak workload durations (tpeak) of 4 min, and recovery durations (trec) of 3 min, 2) short HIIE with Ppeak according to the maximum power output (Pmax) from IET, tpeak of 20 s, and individually calculated trec (26.7 ± 13.4 s), and 3) CE with a target workload (Ptarget) equating to Pmean of HIIE. In short HIIE, mean lactate (Lamean) (5.22 ± 1.41 mmol·l(-1)), peak La (7.14 ± 2.48 mmol·l(-1)), and peak heart rate (HRpeak) (181.00 ± 6.66 b·min(-1)) were significantly lower compared to long HIIE (Lamean: 9.83 ± 2.78 mmol·l(-1); Lapeak: 12.37 ± 4.17 mmol·l(-1), HRpeak: 187.67 ± 5.72 b·min(-1)). No significant differences in any parameters were found between short HIIE and CE despite considerably higher peak workloads in short HIIE. The acute metabolic and peak cardiorespiratory demand during "aerobic" short HIIE was significantly lower compared to long HIIE and regulable via Pmean. Consequently, short HIIE allows a consciously aimed triggering of specific and desired or required acute physiological responses. Key pointsHigh-intensity interval exercise (HIIE) with short peak workload durations (tpeak) induce a lower acute metabolic and peak cardiorespiratory response compared to intervals with long tpeak despite higher peak workload intensities (Ppeak) and identical mean load (Pmean).Short HIIE response is the same as in continuous exercise (CE) matched for Pmean.It is possible to regulate and predict the acute physiological response by means of Pmean for short HIIE but not for long HIIE.The use of fixed percentages of maximal heart rate (HRmax) for exercise intensity prescription yields heterogeneous exercise stimuli across subjects. Therefore, objective individual markers such as the first and the second lactate turn point are recommend prescribing exercise intensity not only for continuous but also for intermittent exercise.

Bone Health, Body Composition and Physiological Demands in 70-85-Year-Old Lifelong Male Football Players.

The effects of lifelong football training on bone health, body composition and physiological demands were evaluated. A total of 20 veteran football players (VPG; 73.4 ± 3.7 years) and 18 untrained age-matched men (CG; 75.6 ± 4.2 years) were enrolled. Whole-body and regional dual-energy X-ray absorptiometry scans of arms, legs, proximal femur and lower spine (L1-L4) were recorded in all participants. We observerd higher bone mineral density (BMD) in the whole-body, arms and femoral regions and higher bone mineral content (BMC) in the legs and lower spine compared to the CG (p < 0.05), also higher total lean body mass (p < 0.05) and lower total body fat percentage (p < 0.05), were found. No differences in food habits were evidenced between the VPG and the CG, as evaluated using 3-day food records. Resting heart rate (RHR), blood pressure (BP) and activity profile during a football match were recorded using a global positioning system only in the VPG. The mean heart rate (HR)of theoretical maximal HR (ThHRmax), and peak of ThHRmax were 83.9 ± 8.6% and 98.6 ± 10.2%, respectively; the mean of total distance covered was 3666 ± 721 m, and the means of accelerations and decelerations were 419 ± 61 and 428 ± 65, respectively. Lifelong participation in football training improves regional BMD and BMC in legs, femur and lumbar spine compared to the CG. A high number of intense actions in term of HR and accelerations and decelerations suggests an elevated energy expenditure that in turn correlates to the healthier body composition observed in the VPG compared to the CG.

Determining the hip joint isokinetic muscle strength and range of motion of professional soccer players based on their field position.

Background: Soccer players' physical and physiological demands vary based on their field position. Although the hip joint has an important role in soccer, little information is available about the strength and flexibility of the hip joint based on player positions. Therefore, this study aims to investigate the differences in muscle strength and flexibility of the hip joint of professional soccer players based on their field position. Methods: Ninety-six professional soccer players from Saudi Arabia were divided into four groups (goalkeepers, defenders, midfielders, and attackers), with 24 participants in each group based on their field position. The Modified Thomas test was used to measure the hip extension range of motion (ROM), and muscle strength was assessed by an Isokinetic dynamometer. Results: There were no statistically significant differences in the isokinetic strength at the hip joint movements between goalkeepers, defenders, midfielders, and attackers (p ≥ 0.05). At the same time, there was a significant difference between groups in the hip extension ROM (p ≤ 0.05). according to different player positions. Post hoc tests reported significant differences between goalkeepers and defenders (p ≤ 0.05), midfielders (p ≤ 0.05), and attackers p ≤ 0.05). At the same time, there were no significant differences between defenders and midfielders (p ≥ 0.05), defenders and attackers (p ≥ 0.05), and midfielders and attackers (p ≥ 0.05). Conclusion: Even though there was no significant difference in isokinetic strength, there was a significant difference in hip extension ROM among players based on field position. This study may help coaches and trainers to recognize the strengths and weaknesses of players and design training programs to rectify the weaker components and improve players' performance in different playing positions.

Effect of Small-Sided Games with and without the Offside Rule on Young Soccer Players: Reliability of Physiological Demands.

This study aimed to compare the physiological demand between three vs. three small-sided games (SSGs) with (3vs.3WITH) and without (3vs.3WITHOUT) the offside rule, as well as the within- and between-session reliability of this demand. Twenty-four U-17 soccer athletes performed various three vs. three (plus goalkeepers) SSGs with and without the offside rule. The data collection was performed within an eight-week period. Athletes' heart rate was monitored during the SSG. The variables analyzed were the percentage mean heart rate (HRMEAN%) and the percentage peak heart rate (HRPEAK%). For the analysis of within-session reliability, the mean value of the first two and last two SSG bouts performed within one day were used. The between-session reliability was calculated using the mean value of the four SSG bouts of each SSG type performed on two different days. In both SSGs, the values for reliability were significant and were classified as moderate to excellent. There were no significant differences in the physiological demand among SSG types. We concluded that the offside rule does not influence the physiological demand in a three vs. three SSG and the HRMEAN% and HRPEAK% present moderate to excellent reliability in a three vs. three SSG with and without the offside rule.

Influence of the Pedagogical Model and Experience on the Internal and External Task Load in School Basketball.

The methodology used by the teacher in Physical Education sessions conditions the physical fitness of the students, since the design of the tasks determines the physical and physiological demands to which they are exposed. This study aimed to quantify and compare, according to the teaching methodology and students' previous experience, the external (eTL) and internal (iTL) load resulting from the application of three intervention programmes that follow different teaching methodologies to teach school basketball: the Tactical Games Approach (TGA), Direct Instruction (DI) and Service Teacher's Basketball Unit (STBU). The Ratings of Perceived Exertion (RPEs) recorded in the assessments (pre-test/post-test) were also studied. A total of 49 students, aged 11 to 12 and divided into three class groups, from the sixth grade of primary education at a state school in Spain, participated in the study. Teaching-learning programs were randomly assigned to student groups. All the sessions were monitored with inertial devices that made it possible to record physical activity and convert the information into kinematic parameters. The results indicated that during the sessions, the students who followed the TGA method recorded higher values of eTL (player load; DI = 4.92, TGA = 6.95, STBU = 2.99) and iTL (mean heart rate; DI = 142.94, TGA = 157.12, STBU = 143.98). In addition, during the evaluation tests, they presented heart rate levels similar to those obtained by the students in the other programmes. However, they spent more time doing high-intensity activity, working longer in the running (DI = 3.42, TGA = 11.26, STBU = 8.32) and sprinting speed ranges (DI = 0.00, TGA = 0.12, STBU = 0.11), and presenting better physical fitness. During the assessments, students with no prior basketball experience showed higher levels of top speed; experienced students had higher levels of heart rate. The TGA method favours the physical condition and health of primary education students, which is why this method is recommended when planning Physical Education sessions.

Quantification of Internal and External Load in School Football According to Gender and Teaching Methodology.

The design of teaching tasks determines the physical and physiological demands that students are exposed to in physical education classes. The purpose of this study is to quantify and compare, according to gender and teaching methodology, the external (eTL) and internal (iTL) load resulting from the application of two programs that follow different teaching methodologies, i.e., a Tactical Games Approach (TGA) and Direct Instruction (DI), to teach school football. The Ratings of Perceived Exertion (RPEs) recorded in the assessments were also studied. A total of 41 students in the fifth year of primary education from a state school from Spain participated in the study (23 boys and 18 girls), aged from 10 to 11 (M ± SD, 10.63 ± 0.49 years) and divided into two class groups. All the sessions were monitored with inertial devices that made it possible to record physical activity and convert the information into kinematic parameters. The results indicated that the students who followed the TGA method recorded higher iTL values (heart rate) and spent more time performing high-intensity activities. Boys recorded higher eTL, iTL, and RPE values than girls. There was an evolution in the RPE between the assessments, with both groups presenting a more efficient RPE in the posttest. The TGA method favors student physical fitness and health, thus, this method is recommended when planning physical education sessions.

The Effect of Small-Sided Game Formats on Physical and Technical Performance in Wheelchair Basketball.

PURPOSE: To examine the effects of different small-sided games (SSGs) on physical and technical aspects of performance in wheelchair basketball (WB) players. DESIGN: Observational cohort study. METHODS: Fifteen highly trained WB players participated in a single 5v5 (24-s shot clock) match and three 3v3 SSGs (18-s shot clock) on a (1) full court, (2) half-court, and (3) modified-length court. During all formats, players' activity profiles were monitored using an indoor tracking system and inertial measurement units. Physiological responses were monitored via heart rate and rating of perceived exertion. Technical performance, that is, ball handling, was monitored using video analysis. Repeated-measures analysis of variance and effect sizes (ESs) were calculated to determine the statistical significance and magnitude of any differences between game formats. RESULTS: Players covered less distance and reached lower peak speeds during half-court (P ≤ .0005; ES ≥ very large) compared with all other formats. Greater distances were covered, and more time was spent performing moderate- and high-speed activity (P ≤ .008; ES ≥ moderate) during full court compared with all other formats. Game format had little bearing on physiological responses, and the only differences in technical performance observed were in relation to 5v5. Players spent more time in possession, took more shots, and performed more rebounds in all 3v3 formats compared with 5v5 (P ≤ .028; ES ≥ moderate). CONCLUSIONS: Court dimensions affect the activity profiles of WB players during 3v3 SSGs yet had little bearing on technical performance when time pressures (shot clocks) were constant. These findings have important implications for coaches to understand which SSG format may be most suitable for physically and technically preparing WB players.

Analysis of chronic physiological demand of an annual soccer season / Análise da demanda fisiológica crônica de uma temporada anual de futebol

Abstract Exercise intensity monitoring has been essential for the control and planning of sports training. Thus, the aim of the present study was to assess the chronic physiological demand of soccer players during an annual soccer season using blood biomarkers. Ten professional soccer players (21.2 ± 3.7 years) participated in this study. Blood samples were collected on the day before beginning of preseason (C1); at the end of preseason and beginning of competitive calendar (C2); and at the end of the competitive calendar. Interleukin-6 (IL-6), cortisol, testosterone, testosterone/cortisol ratio, creatine kinase and alpha-actin were evaluated. Statistical analysis was performed by using ANOVA with repeated measures and the post-hoc Tukey's test. Significance level was set at P<0.05. The results showed significant differences in the following situations: testosterone - C1 higher than C2 and C3; cortisol - C3 higher than C2; testosterone/cortisol ratio - C2 higher than C1, and C3 lower than C1 and C2; creatine kinase - C2 and C3 higher than C1; alpha-actin - C3 higher than C1. IL-6 concentrations were not different between C1, C2 and C3. It could be concluded that an annual soccer season imposes high physiological demand for professional players, since relevant changes in blood biomarkers analyzed were observed.

Resumo O monitoramento da intensidade de esforço entre atletas tem se mostrado essencial para o controle e planejamento do treinamento desportivo. Assim, o objetivo do presente estudo foi avaliar por meio de biomarcadores sanguíneos a demanda fisiológica crônica de jogadores de futebol ao longo de uma temporada anual. Dez jogadores profissionais (21,2 ± 3,7 anos) participaram desse estudo. As coletas de sangue foram realizadas no dia anterior ao início da pré-temporada (C1), ao final da pré-temporada e início das competições (C2), e ao final do ano competitivo (C3). Investigou-se as variáveis cortisol, testosterona, relação testosterona/cortisol, creatina quinase, alfa-actina e interleucina 6 (IL-6). Para a análise estatística dos dados utilizou-se ANOVA para medidas repetidas e foi adotado nível de significância de 5%. Os resultados encontrados indicaram diferenças significativas nas seguintes situações: testosterona - C1 maior do que C2 e C3; cortisol - C3 maior do que C2; relação testosterona/cortisol - C2 maior do que C1, e C3 menor do que C1 e C2; creatina quinase - C2 e C3 maior do que C1; alfa-actina - C3 maior do que C1. As concentrações de IL-6 em C1, C2 e C3 não demonstraram diferenças significativas. Pode-se concluir que uma temporada anual de futebol impõe elevada demanda fisiológica entre jogadores profissionais, uma vez que foram observadas alterações relevantes sobre os biomarcadores sanguíneos analisados.