Are Dryland Strength and Power Measurements Associated with Swimming Performance? Preliminary Results on Elite Paralympic Swimmers.

This study aimed to identify the relationship between dryland tests and swimming performance in elite Paralympic swimmers. Fifteen competitive swimmers (age: 27.4 ± 5.4 years, height: 1.70 ± 6.8 m, body mass: 67.9 ± 9.2 kg; 9 males, 6 females) performed a lat pull-down and a bench press incremental load test to determine maximum power (Pmax), the strength corresponding to maximum power (F@Pmax), and the barbell velocity corresponding to maximum power (V@Pmax) from the force-velocity and power-velocity profiles. These outcomes were also normalized by the athlete's body mass. Swimming performance was carried out from the best result in a 100 m freestyle race registered during an international competition. Lat pull-down F@Pmax was significantly associated with 100 m freestyle chronometric time (ρ = -0.56, p < 0.05), and lat pull-down V@Pmax presented a relationship with mean swimming velocity (ρ = 0.71, p < 0.01). Similarly, bench press F@Pmax and the normalized F@Pmax were significantly related to the mean swimming velocity (ρ = -0.51, ρ = -0.62, p < 0.05). Stepwise multiple regression showed that lat pull-down V@Pmax, bench press normF@Pmax, and V@Pmax accounted for 40.6%, 42.3%, and 65.8% (p < 0.05) of the mean swimming velocity variance. These preliminary results highlighted that simple dryland tests, although with a moderate relationship, are significantly associated with 100 m freestyle swimming performance in elite Paralympic swimmers.

The "thinking system" in a new school concept: A rhythmic teaching approach in physical education to develop creativity.

System Thinking is an actual construct supported by several scientific evidence that offer a perspective on how phenomena relate. Rhythm methodology, teaching-learning, and enjoyment in physical education are the main system elements we hypothesize interacting closely to determine direct or mediated effects on motor creativity and rhythmic perceptive capacity. Seventy-six elementary and middle school students (8.9 ± 2.1 years) were randomly assigned to two groups: a) an intervention group that received a physical education lesson based on rhythmic methodology and b) a control group that received conventional lessons without specific rhythmic interventions. Participants were engaged in eight physical education lessons lasting one hour each for eight weeks. Tests and questionnaires were administered before and after the intervention to evaluate motor creativity, rhythmic perception capacity, self-perception and enjoyment. Two lessons were randomly analyzed to identify the teaching style and motor content (moderate and vigorous activity). The main results revealed direct effects on the intervention group's motor creativity (p = 0.001) and its rhythmic perception capacity (p = 0.02). Furthermore, enjoyment mediated the effects of the intervention on motor creativity (p = 0.01). Finally, the results have shown that self-perception does not mediate the effect of rhythmic intervention group on motor creativity and rhythmic perceptive capacity (p > 0.05). A rhythmic methodology proposed by specific multi-teaching styles can involve children and young people in an enjoyable activity with more moderate to vigorous physical activity.

Effects of cognitive load and different exercise intensities on perceived effort in sedentary university students: a follow up of the Cubo Fitness Test validation.

Work and intellectually fatiguing environments can significantly influence the health of individuals, which is strictly bound to motor efficiency. In particular, desk workers and university students may have a sedentary lifestyle and a condition of mental fatigue caused by daily routine, which could impair motor efficiency. The assessment is a starting point for enhancing awareness of the individual's psychophysical condition through the perception of one's body motor efficiency, motivating to move towards improvement. This way, a submaximal test based on perceived exertion was developed (Cubo Fitness Test, CFT) and validated in previous studies. Hence, two further studies were employed to enhance the consistency and accuracy of this instrument in different conditions. The first study investigated the internal responsiveness of CFT, evaluating if mental fatigue could affect motor efficiency. The second study investigated which perceived intensity (weak, moderate, strong, or absolute maximum) could be more reliable for applying the CFT (as previous research focused the investigation only on moderate intensity). In the first investigation, participants assessed two stimuli (mental fatigue induced with a Stroop color-word task and a neutral condition based on the vision of a documentary) lasting 60 min each. The quality of psychophysical recovery (total quality recovery) and the mood state (Italian Mood State questionnaire) were evaluated before the stimuli. After the fatiguing or the neutral task, the mood state was newly assessed, together with the evaluation of the workload's characteristics (Nasa TLX) and the CFT motor efficiency. In the second investigation, participants had to perform CFT twice for each at different intensities of Borg's Scale of perceived exertion. Researchers successfully requested to fill out the NASA TLX questionnaire regarding the perceived workload characteristics of CFT, and the reliability of each intensity was assessed. Results seem to enhance the consistency and the accuracy of the instrument. Indeed, findings evidenced that CFT is not influenced by mental fatigue conditions typical of the intellectual work of desk workers and university students for which this test was specifically conceived. Moreover, moderate and strong perceived intensity are the most adequate conditions to assess motor efficiency in these populations.

Effects of Musical Classes on Motor Creativity According to Age, Sex, and Weight Status in Young Students: A Music-Oriented versus Conventional Education Plan.

Motor creativity can be influenced by the specificity of the school-class environments (music-based education plans) and individual characteristics. This study aimed to investigate the effects of music oriented and conventional education plans on rhythmic perceptive capacity, motor creativity, and skill- and health-related fitness components in young students according to age, sex, and weight status. One hundred sixty-three young Italian students from elementary (second and fourth grade) and middle school (sixth and eighth grade) were enrolled in the study according to their education plan (music oriented or conventional). All participants were tested for rhythmic perceptive capacity (Stambak's test), motor creativity (Divergent Movement Ability test), skill-related (Körperkoordinationstest Für Kinder), and health-related (Multistage Fitness test) components. Individuals were also considered according to age (elementary and middle school), sex, and weight status. Significant age × education plan and sex × education plan interactions (p < 0.01) were found in motor creativity (locomotor and stability skills) and motor competence (balance and jumping-like activities). No significant weight status × education plan interaction was found. The predominant role of music in the music-oriented education plan appeared to foster the ability to enhance motor creativity in elementary and middle school students compared to the conventional plan. Moreover, music-oriented experience also seems relevant for expressing and exhibiting motor competence (i.e., balance) in relation to sex.

Development, explanation, and presentation of the Physical Literacy Interventions Reporting Template (PLIRT).

BACKGROUND: The physical literacy (PL) concept integrates different personal (e.g., physical, cognitive, psychological/affective, social) determinants of physical activity and has received growing attention recently. Although practical efforts increasingly adopt PL as a guiding concept, latest evidence has shown that PL interventions often lack specification of important theoretical foundations and basic delivery information. Therefore, the goal of the present study was to develop an expert-based template that supports researchers and practitioners in planning and reporting PL interventions. METHODS: The development process was informed by Moher et al.'s guidance for the development of research reporting guidelines. We composed a group of ten distinguished experts on PL. In two face-to-face meetings, the group first discussed a literature-driven draft of reporting items. In the second stage, the experts anonymously voted and commented on the items in two rounds (each leading to revisions) until consensus was reached. RESULTS: The panel recommended that stakeholders of PL initiatives should tightly interlock interventional aspects with PL theory while ensuring consistency throughout all stages of intervention development. The Physical Literacy Interventions Reporting Template (PLIRT) encompasses a total of 14 items (two additional items for mixed-methods studies) in six different sections: title (one item), background and definition (three items), assessment (one item each for quantitative and qualitative studies), design and content (five items), evaluation (one item plus one item each for quantitative and qualitative studies), discussion and conclusion (two items). CONCLUSION: The PLIRT was designed to facilitate improved transparency and interpretability in reports on PL interventions. The template has the potential to close gaps between theory and practice, thereby contributing to more holistic interventions for the fields of physical education, sport, and health.

Enhancing motivation and psychological wellbeing in the workplace through conscious physical activity: Suggestions from a qualitative study examining workers' experience.

Introduction: After COVID-19 restrictions, hybrid solutions were established that combined smart working and work in presence. Workplace conditions significantly impact employees' lives, particularly in terms of meeting their needs and promoting their wellbeing. Based on a socio-ecological and multilevel methodology, the UP150 concept (Proactive Office 150) represents a possible innovative solution to meet employees' needs and valorize flexible work. It encourages physical exercise and active breaks during the typical workday by using particular architectural modifications, a dedicated App, and physical activity professionals as wellness coaches. The present study is the last step of the preliminary actions planned to check the benefits of the UP150 concept and aims to explore the workers' perceptions after experiencing this project. Methods: The qualitative analysis of a preliminary survey (concerning information about the company structure and workers' habits) performed before conducting a randomized controlled trial intervention study and the analysis of the semi-structured interviews after 8 weeks of a UP150 experience served as datasets for this study and have been examined and discussed. Results: In the preliminary survey, the young (under 40) and generally active (57% of the workers) reported being motivated to exercise but inhibited by a lack of time and a heavy workload. After 8 weeks at a modified workplace designed in accordance with the motive behind the UP150, the workers displayed noticeable positive perceptions and appreciation. Discussion: The qualitative analysis confirmed and supported the effectiveness of the UP150 concept that previous research had already found in quantitative parameters related to employees' motor efficiency, psychophysical status, and amount of physical activity. Participants reported beneficial perceived effects on their wellness and psychophysical status following a UP150 experience. Moreover, the concept improved social relationships and increased motivation. In conclusion, the UP150 concept efficiently fostered a positive perception of physical exercise and directed the employees toward the assumption of healthy behaviors fitting the physical literacy paradigm.

The Challenge of Long COVID-19 Management: From Disease Molecular Hallmarks to the Proposal of Exercise as Therapy.

Long coronavirus disease 19 (COVID-19) is the designation given to a novel syndrome that develops within a few months after infection by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and that is presenting with increasing incidence because of the numerous cases of infection. Long COVID-19 is characterized by a sequela of clinical symptoms that concern different organs and tissues, from nervous, respiratory, gastrointestinal, and renal systems to skeletal muscle and cardiovascular apparatus. The main common molecular cause for all long COVID-19 facets appears to be related to immune dysregulations, the persistence of inflammatory status, epigenetic modifications, and alterations of neurotrophin release. The prevention and management of long COVID-19 are still inappropriate because many aspects need further clarification. Exercise is known to exert a deep action on molecular dysfunctions elicited by long COVID-19 depending on training intensity, duration, and continuity. Evidence suggests that it could improve the quality of life of long COVID-19 patients. This review explores the main clinical features and the known molecular mechanisms underlying long COVID-19 in the perspective of considering exercise as a co-medication in long COVID-19 management.

Promoting Children's Psychomotor Development with Multi-Teaching Didactics.

This group randomized control trial examined the dose-response effect of varied combinations of linear and nonlinear pedagogy (enriched physical education with specific program led by specialist vs. conventional physical education led by generalist) for improving first-grade children's motor creativity, executive functions, self-efficacy, and learning enjoyment. We led three physical education classes per group through 12 weeks of combined instruction, based on linear and nonlinear pedagogy: mostly linear (ML; 80% linear, 20% nonlinear; n = 62); mostly nonlinear (MNL; 20% linear, 80% nonlinear; n = 61); and control (C; conventional teaching from generalists; n = 60). MNL improved in (a) motor creativity ability (DMA; 48.7%, 76.5%, and 47.6% for locomotor, stability, and manipulative tasks, respectively); (b) executive functions (working memory and inhibitory control) for RNG task (14.7%) and task errors (70.8%); (c) self-efficacy (5.9%); and (d) enjoyment (8.3%). In ML, DMA improved by 18.0% in locomotor and 60.9% in manipulative tasks. C improved of 10.5% in enjoyment, and RNG task worsened by 22.6%. MNL improvements in DMA tasks, executive functions, and self-efficacy were significantly better than those in C. ML was better than C in DMA task and in executive functions' task errors. Overall, ML and MNL approaches were more effective than conventional generalist teaching (C), and the MNL combination of 80% nonlinear and 20% linear pedagogy was optimal. We recommend that educators favor the MNL approach.

Changes in Upper-Body Muscular Strength and Power in Paralympic Swimmers: Effects of Training Confinement during the COVID-19 Pandemic.

The aim of this case series was to evaluate the effectiveness of a dry-land home-training program conducted during the COVID-19 pandemic period in Paralympic swimmers. Previous evidence showed the importance of muscular strength and power training for Paralympic swimmers due to the positive relationship between severity of impairment, swimming technique and biomechanics parameters. Specifically, we aimed to analyze: (i) the effects of a customized training regime conducted pre, during and post restrictions on upper-body muscular strength and power (one repetition maximum, mean propulsive velocity, and mean relative propulsive power) compared to a regular gym-based program; (ii) the associations between mean propulsive velocity and load during two upper body exercises in order to estimate the one repetition maximum. Four elite Paralympic swimmers were retrospectively analyzed in upper-body muscular strength, mean propulsive velocity and mean relative propulsive power in bench press and lat pull-down exercises at three time points: T0 (prior the Lockdown period), T1 (immediately after the Lockdown confinement), T2 (sixteen weeks after returning to gym training). Our findings suggest a very likely decrement in one repetition maximum, mean propulsive velocity, and mean relative propulsive power during the Lockdown period compared with the T0 period with a subsequent very likely increment in one repetition maximum after returning to gym training (T2) compared with the lockdown period (T0). Conversely, mean relative propulsive power showed an unclear improvement in all athletes in T2 compared with T1. These results were also corroborated by the Friedman's test followed by the Dunn's pairwise comparison that mainly showed a decrement from T0 to T1 (p < 0.05). At the same time, it appears that muscle strength and power could be rapidly restored close to the pre-lockdown levels following an adequate training program in the gym, albeit without significance (p > 0.05). Finally, the close relationship between mean propulsive velocity and load in bench press and lat pull-down exercises was also confirmed in para swimming, making a possible estimation of one repetition maximum.

The UP150: A Multifactorial Environmental Intervention to Promote Employee Physical and Mental Well-Being.

Physical activity (PA) is a major health factor and studies suggest workplaces could promote PA by modifying office design, motivational strategies and technology. The present study aims to evaluate the efficiency of UP150, a multifactorial workplace intervention for the improvement and maintenance of the level of physical fitness (PF) and wellbeing. Forty-five employees were randomly divided into the experimental (EG) and control (CG) groups. The PF was assessed pre-post intervention using the cubo fitness test (CFT), the amount of PA was evaluated using the IPAQ questionnaire and accelerometers while the workload was assessed using the NASA-TLX questionnaire and psycho-physical health by using the SF-12 questionnaire. The EG worked in UP150 offices while the CG worked in their usual offices for 8 weeks. The EG and CG came back 4 weeks after the intervention for CFT retention. The EG improved CFT motor efficiency and the amount of moderate PA, while it reduced mental load. The EG retained reached motor efficiency levels 4 weeks after the intervention. No differences were found in IPAQ. The UP150 demonstrated to be a proactive environment and to be efficient in the promotion of PA, improving PF and mental health while decreasing mental load.

Effects of a nasal breathing protocol on physical fitness and pulmonary function in young basketball players.

BACKGROUND: Respiratory muscle training has been shown to provide positive effects for both health and performance purposes. The aim of this study was to evaluate the effects of a six-week period of nasal breathing on pulmonary function and cardio-respiratory fitness in young basketball players. METHODS: Thirty-four, male, basketball players were enrolled and assigned either to experimental group (EG) or to control group (CG). All participants were tested for Yo-Yo Intermittent Recovery level 1 (Yo-Yo IR1), Shuttle Sprint Test (SST), Forced Vitality Capacity (FVC), Forced Expiratory Volume in one second (FEV1) and Peak Expiratory Flow (PEF). EG group followed reduced breathing frequency training program focused on intermittent running exercises while performing nasal breathing. RESULTS: The main findings were significant interactions in Yo-Yo IR1 test, FVC, FEV1 and PEF (P<0.05) in favor of EG compared to CG. Conversely, no significant changes were detected between EG and CG in the SST total time. CONCLUSIONS: Young basketball players may benefit from nasal breathing protocol during their regular training practice leading remarkable improvements in both physical fitness and pulmonary function.

Biological Rhythm and Chronotype: New Perspectives in Health.

The circadian rhythm plays a fundamental role in regulating biological functions, including sleep-wake preference, body temperature, hormonal secretion, food intake, and cognitive and physical performance. Alterations in circadian rhythm can lead to chronic disease and impaired sleep. The circadian rhythmicity in human beings is represented by a complex phenotype. Indeed, over a 24-h period, a person's preferred time to be more active or to sleep can be expressed in the concept of morningness-eveningness. Three chronotypes are distinguished: Morning, Neither, and Evening-types. Interindividual differences in chronotypes need to be considered to reduce the negative effects of circadian disruptions on health. In the present review, we examine the bi-directional influences of the rest-activity circadian rhythm and sleep-wake cycle in chronic pathologies and disorders. We analyze the concept and the main characteristics of the three chronotypes.

Relationship between Cognitive Functions and Sport-Specific Physical Performance in Youth Volleyball Players.

The aim of this study was to investigate the relationship between basic cognitive functions and sport-specific physical performance in young volleyball players. Forty-three female volleyball players (age 11.2 ± 0.8 years) were tested for cognitive performance by measuring simple reaction time (clinical reaction time), executive control (Flanker task), and perceptual speed (visual search task). Moreover, a set of tests was used to assess physical abilities as volleyball-specific skills (accuracy of setting, passing, and serving) and motor skills (change of direction, vertical jump, and balance). A cumulated value for both cognitive and sport-specific physical performance tests was computed by adding up each test's domain outcomes. Pearson's r correlation analysis showed a large positive correlation (r = 0.45, d-value = 1.01) of the cumulated score summarizing cognitive functions with the cumulated score summarizing sport-specific physical performance. Moreover, small-to-medium correlations (d-value from 0.63 to 0.73) were found between cognitive and motor skills. Given the cumulative scores, these results suggest that volleyball athletes with superior basic cognitive functions present better sport-specific physical performance. Our findings encourage to extend the knowledge of the associations between cognitive and motor skills within a sports performance context.

Local fat content and muscle quality measured by a new electrical impedance myography device: correlations with ultrasound variables.

AbstractThe present study investigated the relationship between local fat percentage (SKfat) and muscle quality (MQ) estimated by a new hand-held electrical impedance myography (hEIM) device or derived from ultrasound and strength assessments. The right anterior thigh of 90 healthy participants (mean ± SD; age=22.9 ± 2.9 years; 45 men: BMI = 23.9 ± 2.4 kgm-2; 45 women: BMI = 21.1 ± 1.9 kgm-2) was scanned by hEIM and ultrasound. Correlations between SKfat, local subcutaneous fat (SUBfat), and echo intensity (EIus) were explored. Correlations between MQ, EIus, quadriceps femoris anatomical cross-sectional area (ACSAQF), knee extensors maximum voluntary isometric torque (T), T/ACSAQF, EIus/SUBfat, and ACSAQF/SUBfat were also assessed. SKfat correlated with SUBfat (r = 0.88; p < 0.001) and EIus (r = 0.64; p < 0.001). MQ correlated with EIus (r = -0.66; p < 0.001), ACSAQF (r = 0.37; p < 0.001), EIus/SUBfat (r = 0.37; p < 0.001), and ACSAQF/SUBfat (r = 0.81; p < 0.001). Multiple regression analysis showed that SUBfat, EIus, and sex explained 86% of SKfat variance, whereas ACSAQF/SUBfat, sex and EIus explained 75% of MQ variance. In conclusion, high hEIM local fat percentage relates to greater subcutaneous fat and intramuscular non-contractile tissue content. High hEIM muscle quality relates to greater muscle-size:subcutaneous-fat ratio and contractile tissue content. Sex influences the prediction of both parameters. This hEIM device seems to be useful to estimate local thigh composition.

Assessing Rolling Abilities in Primary School Children: Physical Education Specialists vs. Generalists.

Teaching physical education requires competencies to conduct the classes and to assess the motor skills of practitioners. Specialists (physical education professionals) and generalists (primary school teachers) differently experienced motor tasks during their academic education. This study aimed to compare the teachers' ability in assessing the children's forward and backward rolls from the analysis of the reliability of an evaluation grid of rolling abilities (Information Scale for Agility on the Soil, InfoSAS), which was investigated in a first study with teachers. A second study in young children explored the responsiveness of the InfoSAS to discriminate by skill level or by training effects. When administered by specialists, the InfoSAS resulted in being reliable (forward: p = 0.087 and p = 0.908; backward: p = 0.926 and p = 0.910; intra- and inter-rater reliability, respectively) and responsive in detecting differences due to expertise (gymnasts vs. primary school children; forward: p = 0.003, backward: p = 0.016) or improvements after specific training in rolling (pre- vs. post-children's training; forward: p = 0.005, backward: p = 0.001). The results support the conclusion that specialists exhibit higher competence than generalists, which allows proper application of the InfoSAS, possibly because of the practice of skills and reflective teaching styles in physical activity they experienced, along with their academic education in sport sciences.

Passive Drag in Young Swimmers: Effects of Body Composition, Morphology and Gliding Position.

The passive drag (Dp) during swimming is affected by the swimmer's morphology, body density and body position. We evaluated the relative contribution of morphology, body composition, and body position adjustments in the prediction of a swimmer's Dp. This observational study examined a sample of 60 competitive swimmers (31 male and 29 female) with a mean (±SD) age of 15.4 ± 3.1 years. The swimmer's Dp was measured using an electro-mechanical towing device and the body composition was assessed using a bioelectrical impedance analyser. Body lengths and circumferences were measured in both the standing position and the simulated streamlined position. Partial correlation analysis with age as a control variable showed that Dp was largely correlated (p < 0.05) with body mass, biacromial- and bi-iliac-breadth, streamline chest circumference and breadth. Body mass, Body Mass Index, chest circumference and streamline chest circumference showed a significant and moderate to strong effect (η2 > 0.55) on Dp. Body mass was the best predictor of Dp explaining 69% of the variability. These results indicate that swimmers with lower Dp values were: (i) slimmer, with lower fat and fat-free mass, (ii) thinner, with lower shoulder breadth, chest circumference, and streamline trunk diameters (iii), shorter, with lower streamline height. These findings can be used for talent identification in swimming, with particular reference to the gliding performance.

Effects of in-season enhanced negative work-based vs traditional weight training on change of direction and hamstrings-to-quadriceps ratio in soccer players.

The present study investigated the effects of in-season enhanced negative work-based training (ENT) vs weight training in the change of direction (COD), sprinting and jumping ability, muscle mass and strength in semi-professional soccer players. Forty male soccer players participated in the eight-week, 1 d/w intervention consisting of 48 squat repetitions for ENT using a flywheel device (inertia=0.11 kg·m -2 ) or weight training (80%1 RM) as a control group (CON). Agility T-test, 20+20 m shuttle, 10 m and 30 m sprint, squat jump (SJ) and countermovement jump (CMJ), lean mass, quadriceps and hamstrings strength and the hamstrings-to-quadriceps ratio were measured. Time on agility T-test and 20+20 m shuttle decreased in ENT (effect-size =-1.44, 95% CI -2.24/-0.68 and -0.75, -1.09/-0.42 respectively) but not in CON (-0.33, -0.87/0.19 and -0.13, -0.58/0.32). SJ and CMJ height increased in both ENT (0.71, 0.45/0.97 and 0.65, 0.38/0.93) and CON (0.41, 0.23/0.60 and 0.36, 0.12/0.70). Overall, quadriceps and hamstrings strength increased in both ENT and CON (0.38/0.79), but the hamstrings-to-quadriceps ratio increased in ENT (0.31, 0.22/0.40) but not in CON (0.03, -0.18/0.24). Lean mass increased in both ENT (0.41, 0.26/0.57) and CON (0.29, 0.14/0.44). The repeated negative actions performed in ENT may have led to improvements in braking ability, a key point in COD performance. Semi-professional soccer players may benefit from in-season ENT to enhance COD and the negative-specific adaptations in muscle strength and hamstrings-to-quadriceps ratio.

Physiological and technical commitment during a 300-m in-line skating trial in athletes of different age categories.

BACKGROUND: This study investigated the differences in strength, technique and time performance in in-line skaters of three age categories during a 300-meter trial. Possible correlations among these variables were also assessed. METHODS: Thirty-six elite in-line skaters (Cadets, Juniors and Seniors, N.=12 each; 14±1, 16±1, and 24±6 years of age, respectively) performed a 300-m trial on an outdoor oval track. Total time (Ttot), 100-m fractions and duration of each skating technique (initial acceleration phase, straight push and cross-over) were recorded. A squat jump (SJ) was performed before and after the trial. Heart rate, blood lactate concentration ([La-]) and rate of perceived exertion (RPE) were collected before, during and at the end of the trial. RESULTS: Ttot was longer and SJ lower in Cadets compared to the other groups. Seniors employed the cross-over technique for a longer period than the straight push technique, compared to Juniors and Cadets. Ttot correlated negatively with SJ in Seniors. The number of significant correlations between skating techniques' duration and both Ttot and SJ increased with age category. No differences among groups were found for heart rate, [La-] and RPE. CONCLUSIONS: With increasing age category, leg strength appeared to be the more related aspect to skating performance. To improve 300-m in-line skating performance, trainers should pay particular attention to the enhancement of leg strength and cross-over skating technique.

Techniques and considerations for monitoring swimmers' passive drag.

Drag is the resistant force that opposes a swimmer displacing through water and significantly affects swimming performance. Drag experienced during active swimming is called active drag (Da), and its direct determination is still controversial. By contrast, drag experienced while gliding in a stable streamlined body position is defined as passive drag (Dp), and its assessment is widely agreed upon. Dp reduction preserves the high velocity gained with the push-off from the starting block or wall after starting and turning or improves the gliding phase of the breaststroke cycle. Hence, this paper reviewed studies on swimming that measured Dp under different conditions of gliding. In the present research, accurate descriptions of the main methods used to directly or indirectly determine Dp are provided and the main advantages, limitations and critical features of each method are discussed. Since Dp differs in methods but not in reported values and is consistent regardless of the measuring method, the information provided in this paper might allow coaches and practitioners to identify the most suitable method for assessing and determining the drag of their swimmers.

Effects of knee extension with different speeds of movement on muscle and cerebral oxygenation.

BACKGROUND: One of the mechanisms responsible for enhancing muscular hypertrophy is the high metabolic stress associated with a reduced muscular oxygenation occurring during exercise, which can be achieved by reducing the speed of movement. Studies have tested that lowered muscle oxygenation artificially induced by an inflatable cuff, could provoke changes in prefrontal cortex oxygenation, hence, to central fatigue. It was hypothesized that (1) exercising with a slow speed of movement would result in greater increase in cerebral and greater decrease in muscle oxygenation compared with exercises of faster speed and (2) the amount of oxygenation increase in the ipsilateral prefrontal cortex would be lower than the contralateral one. METHODS: An ISS Imagent frequency domain near infrared spectroscopy (NIRS) system was used to quantify oxygenation changes in the vastus lateralis muscle and prefrontal cortex (contra- and ipsilateral) during unilateral resistance exercises with different speeds of movement to voluntary fatigue. After one maximal repetition (1RM) test, eight subjects performed three sets of unilateral knee extensions (∼50% of 1RM), separated by 2 min rest periods, following the pace of 1 s, 3 s and 5 s for both concentric and eccentric phases, in a random order, during separate sessions. The amount of change for NIRS parameters for muscle (ΔHb: deoxyhemoglobin, ΔHbO: oxyhemoglobin, ΔHbT: total hemoglobin, ΔStO2: oxygen saturation) were quantified and compared between conditions and sets by two-way ANOVA RM. Differences in NIRS parameters between contra- and ipsilateral (lobe) prefrontal cortex and conditions were tested. RESULTS: Exercising with slow speed of movement was associated to larger muscle deoxygenation than normal speed of movement, as revealed by significant interaction (set × condition) for ΔHb (p = 0.01), and by significant main effects of condition for ΔHbO (p = 0.007) and ΔStO2 (p = 0.016). With regards to the prefrontal cortex, contralateral lobe showed larger oxygenation increase than the ipsilateral one for ΔHb, ΔHbO, ΔHbT, ΔStO2 in each set (main effect of lobe: p < 0.05). Main effects of condition were significant only in set1 for all the parameters, and significant interaction lobe × condition was found only for ΔHb in set1 (p < 0.05). DISCUSSION: These findings provided evidence that speed of movement influences the amount of muscle oxygenation. Since the lack of oxygen in muscle is associated to increased metabolic stress, manipulating the speed of movement may be useful in planning resistance-training programs. Moreover, consistent oxygenation increases in both right and left prefrontal lobes were found, suggesting a complementary interaction between the ipsi- and contralateral prefrontal cortex, which also seems related to fatigue.