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Showing papers in "Journal of Sports Medicine and Physical Fitness in 2020"


Journal ArticleDOI
TL;DR: Lockdown measures, including isolation, impacted negatively on the PA levels of the already inactive or moderately active young population, and government actions should enhance strategies to control physical inactivity during pandemics like COVID-19.
Abstract: Background Italy early experienced one of the most suffering impact of the COVID-19 outbreak in terms of number of cases and death toll. Progressively, more compelling national restrictions hardened citizens' lifestyle and habits, including limiting mobility and outdoor physical activity (PA). In a second phase, people were allowed to perform outdoor activities close to their houses and thereafter motor or sports activity were gradually reintroduced. These drastic changes raised the question on how to cope and exploit the residual opportunities of PA under circumstances of home confinement. Methods International Physical Activity Questionnaires were administered to 1,568 youngsters from North-western Italian high schools, before, during, and after lockdown enacted by Italian Government to contrast the COVID-19 pandemic. Results Student's PA levels were significantly different before (1676.37 ± 20.6 MET-min/week) and after (1774.50 ± 33.93 MET-min/week) the governmental restrictions (TIME effect: F=3.49; ηp 2 = 0.005 p=0.03). There was a significant TIME*CATEGORY interaction effect (F=8.37; ηp 2 = 0.021; p 2520 MET-min/week) increased their PA during (3467.48 ± 55.85 MET-min/week) and after (3515.73 ± 65.75 MET-min/week) the lockdown measures with respect to their baseline levels (3151.43 ± 42.41 MET-min/week). Conclusions Lockdown measures, including isolation, impacted negatively on the PA levels of the already inactive or moderately active young population. Government actions should enhance strategies to control physical inactivity during pandemics like COVID-19.

36 citations


Journal ArticleDOI
TL;DR: The aim of this review is to show the role of some well-known myokines in the maintenance of homeostasis and to open a new direction in understanding the effects of exercises on humans.
Abstract: In the last years, scientists have shown that skeletal muscle is not a pure locomotor unit or responsible for propulsion and posture Skeletal muscle encompasses one of the major organs of the body (constituting about 40% of the body mass in non-obese men) It regulates energy and metabolic processes and is now recognized as an organ capable of producing molecules with vital functions These molecules are termed myokines, a new field of research in the health sciences, and represent an open field of discoveries and applications in several areas The aim of this review was to show the role of some well-known myokines in the maintenance of homeostasis Our search was performed in databases such as Medline/Pubmed, Embase and Scielo Some relevant myokines are interleukin-6 (IL-6), IL-8, IL-15, irisin, myostatin, fibroblast growth factor 21 (FGF21), leukemia inhibitory factor (LIF), brain-derived neurotrophic factor (BDNF), and insulin-like growth factor-1 (IGF-1) They are related to play a positive or negative role in muscle function and metabolism homeostasis They are associated with the regulation of glucose and lipid metabolism, the deposition of fat in the adipose tissue, and the "browning" of the white adipose tissue For these reasons, they can interfere with the prevention of obesity, diabetes, metabolic syndrome, and cardiovascular diseases The discovery of the myokines has opened a new direction in understanding the effects of exercises on humans

21 citations


Journal ArticleDOI
TL;DR: Investigation of the relations between the players' speed, aerobic capacity, body composition and distance covered in different speed zones during official soccer matches indicates that professional soccer players with lower fat content and higher levels of aerobic capacity are able to cover longer distances in sprinting and HSR during official matches.
Abstract: BACKGROUND The importance of sprinting and high-speed running activities during a soccer match is indisputable. The main purpose of this study was to investigate the relations between the players' speed, aerobic capacity, body composition and distance covered in different speed zones during official soccer matches and to compare the match performance variables according to playing position. METHODS Twenty-three professional soccer players (age: 27.9±4.58 y, body mass: 78.8±7.35 kg, height: 181.7±6.53 cm) participated in this study. During 13 weeks of the competitive season, players participated in 16 official matches and completed body composition analyses, sprint tests, multistage shuttle run tests (MST), and incremental running tests (IRTs). RESULTS Significant negative correlations were found between sprint distance and percent of fat mass (FM; r=-0.57, P<0.0001), MST (r=0.45, P<0.001), maximal speed (r=0.44, P<0.001). High-speed running (HSR) distance covered by the players during the matches was significantly correlated with FM (r=-0.38, P<0.001) and MST distance (r=0.30, P<0.01). CONCLUSIONS These data indicate that professional soccer players with lower fat content and higher levels of aerobic capacity are able to cover longer distances in sprinting and HSR during official matches.

19 citations


Journal ArticleDOI
TL;DR: Tai Chi training plus routine exercise might be an ideal alternative non-pharmacological approach for the motor and non-motor symptoms of PD patients, and especially be more useful for the improvement of sleep quality and cognitive function in Parkinson's disease compared with routine exercise regimen alone.
Abstract: Background Tai Chi, a kind of physical exercise, may act as a non-pharmacologic approach to reducing the symptoms of Parkinson's disease. This study was conducted to investigate the effect of simplified Tai Chi training plus routine exercise on motor and non-motor symptoms in patients with mild to moderate Parkinson's disease in comparison with routine exercise regimen alone. Methods Forty-one outpatients and inpatients with Parkinson's disease (PD) were randomized into Tai Chi group (N.=19) and routine exercise group as control group (N.=22) for 12 weeks. The Tai Chi group included both Tai Chi traning and routine exercise. Motor and non-motor functions were assessed. Motor function was evaluated by Unified Parkinson's Disease Rating Scale part III (UPDRS-III) and Berg Balance Scale (BBS). The non-motor symptoms like quality of life, sleep quality, depression and anxiety state, cognitive function were assessed by Parkinson's Disease Questionnaire-39 (PDQ-39), Parkinson's Disease Sleep Scale (PDSS), Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), Montreal Cognitive Assessment (MOCA) respectively. Results After 12 weeks of intervention, participants in both Tai Chi and routine exercise groups gained effects in UPDRS-III, BBS, PDQ-39, PDSS and HAMD compared to the baseline. However, significant improvements between Tai Chi group and routine exercise group were only found in PDSS (P=0.029) and MoCA (P=0.024). Conclusions Tai Chi training plus routine exercise might therefore be an ideal alternative non-pharmacological approach for the motor and non-motor symptoms of PD patients, and especially be more useful for the improvement of sleep quality and cognitive function in Parkinson's disease compared with routine exercise regimen alone.

19 citations



Journal ArticleDOI
TL;DR: The results of the present study indicated that a 6-week CST did not improve dynamic balance, vertical jump height and throwing velocity in adolescent male handball players, and it is believed that longer CST programs may provide significant benefits.
Abstract: Background The aim of this study was to examine the effects of core strength training (CST) on dynamic balance and vertical jump height, and throwing velocity in handball players. Methods Twenty male handball players (mean age 14.90±0.44 years) participated in this study. The players randomly divided into two groups as CST and control (CON) groups. Dynamic balance, vertical jump, and throwing velocity were measured before and after a six-week CST. Results Significant differences were found at anterior (P=0.009) and posteromedial (P=0.017) directions of the Star Excursion Balance Test (SEBT) in only CST group. There were significant improvement in vertical jump height of participants compared to pre-test scores in both CST (P=0.047) and CON group (P=0.013). No significant difference was found for throwing velocity compared with pre-test in both groups. There were no significant differences in all parameters when CST and CON groups were compared (P>0.05). Conclusions The results of the present study indicated that a 6-week CST did not improve dynamic balance, vertical jump height and throwing velocity in adolescent male handball players. We believe that longer CST programs may provide significant benefits.

16 citations



Journal ArticleDOI
TL;DR: Male athletes better performed than women in all the fitness tests, and physical fitness comparisons between beach handball elite male athletes of different ages and between genders were showed for the first time.
Abstract: Background The aims of this study were to compare anthropometric and fitness variables of high-level beach handball players across Under-19 (U-19), Under-21 (U-21) and senior male categories, and between male and female senior players; and to test the correlations among those measures Methods A total of 70 high-level players (53 male of different ages) were evaluated for 5-m acceleration, 15-m sprint, horizontal jump, handgrip strength, specific beach handball throwing velocities, and anthropometric variables Differences between age groups were tested using ANOVA Independent t-test was used to compare fitness variables between male and female elite athletes, and Pearson partial correlation coefficients were calculated between each of the fitness variables using BMI and age as covariates SPSS Software was used, and the level of significance was set at 95% Results The U-21 athletes better performed on horizontal jump and 6-m throw than the U-19 athletes Senior athletes showed better performance on horizontal jump than U-19 athletes (P≤005) Positive correlation was seen for handgrip on dominant and non-dominant hands and 6-m throwing speed, and for handgrip on dominant hand and inflight velocity (P≤005) Negative correlations were observed between horizontal jump and 5-m acceleration, and 15-m sprint (P≤001 and P≤005, respectively) Conclusions Male athletes better performed than women in all the fitness tests The study, for the first time, showed physical fitness comparisons between beach handball elite male athletes of different ages and between genders These are key steps for coaches and athletes and may support future beach handball studies and practice

15 citations


Journal ArticleDOI
TL;DR: A strong correlation between PhA and hand grip strength in both volleyball players and in controls was found, and it was confirmed that body composition differed between volleyballPlayers and non-athletic subjects.
Abstract: BACKGROUND The assessment of body composition is central in evaluating athletes' nutritional status and the effects of training. The aim of this study was to evaluate body composition and the relation between bioimpedance phase angle (PhA) and muscular strength in elite female volleyball players. METHODS Twelve volleyball players (age 23.8±3.6 years; weight 63.0±5.1 kg; height 170±4 cm; BMI 21.9±1.3 kg/m2) and 22 non-athletic females, who served as a control group (age 23.6±2.0 years; weight 60.7±4.8 kg; height 167±5 cm; BMI 21.9±1.3 kg/m2), participating in the study. Skinfold thickness measures were used and segmental bioelectrical impedance analysis (BIA) was performed. Additionally, hand grip strength was used to evaluate muscular strength. RESULTS Volleyball players had lower FM and higher FFM than controls (FM(kg)=15.7±2.7 vs. 18.0±3.0, P=0.036; FM(%)=24.8±3.0 vs. 29.5±3.8, P=0.001; FFM(kg)=47.4±3.5 vs. 42.8±3.6, P=0.001). Both whole-body and segmental PhA were higher in volleyball players (P<0.05) than in controls, whereas no differences were observed for hand grip strength. A positive relation was found between hand grip strength and whole-body and upper limbs PhA in all subjects, resulting stronger in volleyball players (r=0.696, P=0.012 and r=0.821, P=0.001, respectively). CONCLUSIONS The data confirmed that body composition differed between volleyball players and non-athletic subjects. In addition, a strong correlation between PhA and hand grip strength in both volleyball players and in controls was found. However, further evaluations are needed to investigate the use of hand grip strength in sport performance.

14 citations


Journal ArticleDOI
TL;DR: Swimmers may benefit more from submaximal prolonged conditioning activities such as resisted swimming rather than high-resistance dry-land sets to obtain performance enhancements.
Abstract: Background The swimming community has shown considerable interest in using dry-land warm-ups as a method of impacting performance This study compared the effects of high-resistance pull-over and swimming warm-up in semi-tethered resisted swimming Methods An incremental-load semi-tethered swimming test was individually administered in 20 national-competitive swimmers to determine the load maximizing swimming power In different sessions, participants tested such a load 6 min after a swimming warm-up (SWU) or a dry-land warm-up (DLWU: 3 pull-over reps at 85% of the one-repetition maximum) Kinetic variables (velocity, force, acceleration, impulse, power rate of force development [RFD] and intra-cycle variation), were obtained with a linear encoder through trapezoidal integration regarding time Kinematic variables (distance, time, stroke-rate and stroke-length), were obtained by video recordings The differences between protocols were observed by paired-samples t-test (ANOVA) Pearson's coefficient explored correlations between kinetics and kinematics variables; significance was set at P Results DLWU increased RFD (3452±1655 vs 3129±1370 N/s; Δ=935%) and stroke-rate (6470±984 vs 6156±707 Hz; Δ=510%) compared to SWU, but decreased velocity, force, acceleration, impulse and power During the incremental-load test velocity and power were higher than obtained after SWU (121±014 vs 117±012 m/s; Δ=306%), (5138±1493 vs 4998±1540 W; Δ=272%), suggesting enhancements prompted by the test itself Correlations between stroke-length with impulse (r=076) and power (r=075) associated kinetics with kinematics Conclusions Potentiation responses were present after the dry-land warm-up However, swimmers may benefit more from submaximal prolonged conditioning activities such as resisted swimming rather than high-resistance dry-land sets to obtain performance enhancements

13 citations


Journal ArticleDOI
TL;DR: It is reported for the first time that the use of RIR-based RPE resistance training protocol promotes improvements in high-intensity actions, muscle power output, and maximum strength, particularly in youth athletes.
Abstract: Background This study aimed to analyze and compare the effects of two different resistance training programs Methods Fourteen under-17 youth female basketball players were randomly assigned to repetitions in reserve (RIR, N=7) or maximum effort (RM, N=7) resistance training programs The programs consisted of 3-4 sets of 4 exercises x 7-10 repetitions with 2 min of passive recovery between sets and exercises, twice a week for a period of 8 weeks The RIR group was instructed to perform the exercises with 3 repetitions remaining (rate of perceived exertion [RPE] =7) The physical assessment included jumping, agility, and sprinting tests Moreover, the maximum strength (one maximum-repetition [1-RM]) and muscle power output at 60% 1RM were assessed for back-squat and bench-press exercises Results The within-group analysis showed improvements in all tests for both groups (RIR=13-439%; RM=13-172%) Between-group analyses showed a significant interaction effect (group x time) on 1-RM bench-press (F=807, P p =040), favoring RIR group Conclusions This study reports for the first time that the use of RIR-based RPE resistance training protocol promotes improvements in high-intensity actions (sprinting, jumping, and cutting), muscle power output, and maximum strength, particularly in youth athletes Considering the advantages of non-failure training, RIR training may be a suitable in-season training strategy However, more studies are needed to confirm whether the training-induced benefits of this novel training strategy are significantly better as compared to other approaches

Journal ArticleDOI
TL;DR: The relationship between force-time characteristics achieved from ISqT with CMJ and sprint performances changed after a period of strength training.
Abstract: BACKGROUND The effect of strength training on the relationship between isometric force-time characteristics with dynamic performances is still unknown. Therefore, the purpose of this study was to investigate if strength training would alter relationship between the force-time characteristics achieved from isometric squat (ISqT) with dynamic performances. METHODS Six female and 18 male elite floorball athletes (age: 24±3 years; stature: 1.68±0.07 m; body mass: 64.4±10.7 kg) performed a countermovement jump (CMJ), 20-m sprint and ISqT at 90° (ISqT90) and 120° (ISqT120) knee angles during the preliminary test. Subsequently, they underwent 12 strength training sessions over six weeks and repeated the three tests upon completion of training. RESULTS ISqT and CMJ improved significantly post-training (P<0.01). Before training, all measures of ISqT90 were significantly correlated to CMJ height and sprint times (r=0.56 to 0.63, P<0.01 and r=-0.42 to -0.58, P<0.05, respectively), while only rate of force development (RFD) measures of ISqT120 were significantly correlated to CMJ height and sprint times (r=0.55 to 0.56, P<0.01 and r=-0.51 to -0.53, P<0.05, respectively). After training, all measures of ISqT90 were significantly correlated to CMJ height (r=0.43 to 0.71, P<0.05), while only PF achieved from ISqT120 was significantly correlated to CMJ height (r=0.43, P<0.05). CONCLUSIONS The relationship between force-time characteristics achieved from ISqT with CMJ and sprint performances changed after a period of strength training.

Journal ArticleDOI
TL;DR: In the ML phase, which causes increased core temperature and minute ventilation, RE is impaired at exercise intensities that are applicable to training and performance, and in physiologically stressful environments, this impairment in RE may have a significant impact onTraining and performance.
Abstract: Background The aim of this study was to examine the effect of the menstrual cycle on running economy (RE). Methods Using a repeated-measures design, ten eumenorrheic, trained female runners (age: 32±6 yrs, VO2max: 59.7±4.7 mL·kg-1·min-1) completed four, weekly, identical sub-maximal and maximal incremental step tests on a treadmill to measure physiological responses across a full menstrual cycle. For phase comparison, the results from the trials that fell in the early follicular (low estrogen, low progesterone), late follicular (high estrogen, low progesterone) and mid-luteal (high estrogen, high progesterone) phases were used. Results There was a significant effect of menstrual cycle phase on RE (P=0.001), with RE in the mid-luteal (ML) phase being worse than that of the early follicular (EF) (+2.33 mL·kg-1·min-1; P=0.026) and late follicular (LF) (+2.17 mL·kg-1·min-1; P=0.011) phases. The ML phase also resulted in elevated core temperature versus the EF (+0.51 oC; P=0.001) and LF (+0.66 oC; P=0.037) phases, and elevated minute ventilation versus the EF phase (+3.83 L·min-1; P=0.003). No significant effects of menstrual cycle phase were found on body mass, heart rate, ratings of perceived exertion, time-to-exhaustion, maximal oxygen consumption, or blood lactate concentration. Conclusions In the ML phase, which causes increased core temperature and minute ventilation, RE is impaired at exercise intensities that are applicable to training and performance. In physiologically stressful environments, this impairment in RE may have a significant impact on training and performance.

Journal ArticleDOI
TL;DR: It was showed that AR, NMES, and FR have similar effects on Bla removal, performance recovery, and DOMS reduction in healthy young individuals.
Abstract: Background Recovery from exercise is important in sports and rehabilitation for preventing exercise-induced injuries and recovery of performance. This study aimed to compare active recovery (AR), neuromuscular electrical stimulation (NMES), and foam rolling (FR) in terms of blood lactate (Bla) removal, reduction in delayed-onset muscle soreness (DOMS), and restoration of muscle strength, endurance, and flexibility in healthy young individuals. Methods Forty-five subjects aged 20-25 years were assigned to AR, FR, and NMES groups. The subjects performed a single bout of circuit-based high-intensity training (CBHIT) at 85% of the heart rate reserve (HRR). The subjects in the AR group walked at 40% of the HRR, whereas those in the FR group self-massaged the tight muscles. In the NMES group, electrical stimulation was applied to the hamstrings and quadriceps. All recovery methods took 15 minutes. The sit-and-reach performance, quadriceps and hamstring strength, and squat endurance of the subjects were measured prior to CBHIT and after recovery. Bla concentrations were measured before CBHIT and at 0, 5, and 20 minutes of recovery. The DOMS were evaluated for 3 days. Results After recovery, no significant differences were found between the groups in terms of quadriceps (right, P=0.82; left, P=0.772) and hamstring (right, P=0.41; left, P=0.30) strength, sit-and-reach performance (P=0.55), squat endurance (P=0.18), Bla concentration at each time point (P=0.94), and DOMS (P=0.31). Conclusions This study showed that AR, NMES, and FR have similar effects on Bla removal, performance recovery, and DOMS reduction in healthy young individuals.

Journal ArticleDOI
TL;DR: The SV players have an asymmetrical rotational strength profile, with a greater asymmetry between both shoulders in the male players compared to the female players, preference for the dominant side in both groups.
Abstract: Background Sitting volleyball (SV) is a popular Paralympic game, in which shoulders of SV players are overloaded continuously during play. Nevertheless, shoulder girdle muscle function has never been measured in this population yet. The objective of this study was to investigate the dominant and non-dominant strength profile of male and female elite SV players on a glenohumeral level. Methods A total of 13 Brazilian SV national team players volunteered to participate in this study (male: N.=6, age 32.8±4.1 years, body mass 83.2±19.4 kg, seated height 1.47±0.04 m; female: N.=7, age 32.8±4.1 years, body mass 80.1±17.9 kg, seated height 1.36±0.05 m). A Biodex dynamometer was used to measure internal rotation (IR) and external rotation (ER) of the glenohumeral muscle strength at 60°/s and 180°/s velocities in a concentric/concentric mode. Results It was observed that male SV players were stronger than the female players at both upper limbs. Concerning the side effects, significant differences were found for IR at 60°/s velocity (F=7.55, P=0.02) and ER at 180°/s velocity (F=5.91, P=0.03), with higher values on the dominant limb in comparison to the non-dominant limb for both the male and female players. There were significant gender differences for the IR inter-limb asymmetry at 180°/s velocity, with a greater asymmetry between both shoulders in the male players compared to the female players, preference for the dominant side in both groups. Conclusions The SV players have an asymmetrical rotational strength profile. As muscular imbalance is a common injury pattern among overhead players. The findings of this study may assist the SV coaches and physiotherapists for evaluation and training of strength of the ER and IR shoulders of these players.

Journal ArticleDOI
TL;DR: Training more than four days a week and do not receive regular physiotherapeutic care were associated with CrossFit-related musculoskeletal injuries.
Abstract: Background CrossFit® is usually composed of high intensity workout routines and is executed quickly, repetitively and with limited rest time. Previous studies have identified a high prevalence of injuries in CrossFit®. This study aimed to determine the prevalence of CrossFit-related musculoskeletal injuries and to identify potential associated factors. Methods A cross-sectional study was conducted with 413 CrossFitters. Participants completed a questionnaire containing personal data, training characteristics and injury history in the last 12 months. Data were analyzed by descriptive statistics and logistic regression models. Results The prevalence of CrossFit-related musculoskeletal injuries was 24.0%; and the injury rate was of 0.80 injuries per 1,000 hours of exposure. The regions of the body most affected were the lumbar spine (33.3%), shoulders (31.3%) and knees (14.1%). The majority of CrossFitters participated in competitions (74.6%), had more than 12 months of experience in CrossFit® (62.7%), and trained up to 90 minutes a day (82.3%) for more than 4 days a week (76.8%). The variables that showed a significant association with CrossFit®-related musculoskeletal injuries were weekly training frequency (OR=2.25; 95% CI: 1.13-4.48) and regular physiotherapeutic care (OR=1.85; 95% CI: 1.11-3.07). Conclusions The prevalence of musculoskeletal injury was 24.0%, and the most affected regions of the body were the lumbar spine, shoulders and knees. Training more than four days a week and do not receive regular physiotherapeutic care were associated with CrossFit-related musculoskeletal injuries.

Journal ArticleDOI
TL;DR: Different types of exercise have different intervention effects on the outcome of patients with gestational diabetes, and it is still necessary to conduct large-scale, high-quality and long-term intervention studies for verification.
Abstract: Introduction There is evidence that maternal and child outcomes in patients with gestational diabetes mellitus (GDM) are associated with different exercise patterns. However, the evidence on which forms of exercise are beneficial for pregnant women with GDM is unclear. Evidence acquisition PubMed, EMBASE, the Cochrane Library and the Web of Science were systematically searched for eligible studies until Feb.24, 2019. A randomized controlled trial (RCT) was used as the study method. The literature quality was evaluated and the data extracted by two researchers, and statistical analysis was carried out using Review Manage 5.2 software. Evidence synthesis A total of nine RCTs were included. The research results show that compared with the conventional treatment group, aerobic exercise reduced the fasting blood glucose (WMD=-0.35, 95% CI: -0.62 to -0.08, I2=87%), postprandial blood glucose (WMD=-0.62, 95% CI:-0.95 to -0.29, I2=84%) and glycosylated hemoglobin levels (WMD=-0.35, 95% CI:-0.49 to -0.20, I2=71%) in patients with GDM. Compared with the conventional treatment group, the dosage of insulin (WMD=0.97, 95% CI: 0.42-2.26, I2=0%) in patients with GDM in the resistance exercise group was reduced, and the effect of combined treatment was statistically significant. Compared with the conventional treatment group, the combination of aerobic exercise plus resistance exercise training reduced postprandial blood glucose in patients with GDM (WMD=-0.64, 95% CI:-0.94 to -0.34), and the combined treatment effect was statistically significant. Conclusions Different types of exercise have different intervention effects on the outcome of patients with gestational diabetes. However, we do not have enough data to determine whether infants benefit from this exercise, and it is still necessary to conduct large-scale, high-quality and long-term intervention studies for verification.

Journal ArticleDOI
TL;DR: The results suggested that the scaling method identified the optimal height-to- body mass ratios associated with Cooper endurance test corresponding to ectomorph body shape.
Abstract: BACKGROUND The Cooper Test, is a field test, simple and useful in the school context. The aim of this research was the definition of the trend in Cooper endurance test along with the growth. In particular, through the scaling method (allometric). METHODS A total of 556 of European sedentary children aged 11-13 years (282 boys; 274 girls) were involved. All subjects were evaluated through the Endurance Cooper test (12 min run test). To identify the most appropriate body size and shape characteristics as well as any categorical differences (sex, age) associated with the measure of the Cooper test, a multiplicative model with allometric body-size components was applied. RESULTS The multiplicative model relating to the Cooper test and the body-size components was: Cooper test = a · mass-0.325 · height0.878 with the mass and height exponents being k1=-0.325 (SEE=0.40) and k2= 0.878 (SEE=0.141), respectively. The adjusted coefficient of determination (adj R2) was 32.3%, with a log-transformed error ratio of 0.136 or 14.5% having taken antilogs. Significant differences in the constant 'a' parameter were identified by sex (P<0.001) and age (P<0.001) while the interaction of sex per age was not significant (P=0.761). CONCLUSIONS The results suggested that the scaling method identified the optimal height-to-body mass ratios associated with Cooper endurance test corresponding to ectomorph body shape. Furthermore, growth fluctuations become important to avoid alarming judgment in case children will be poorly evaluated.

Journal ArticleDOI
TL;DR: PJT interventions that included a programmed taper induced significant improvements inJump performance in team-sport athletes after different tapering strategies in terms of volume, taper duration, and the type of PJT prescribed.
Abstract: INTRODUCTION The purpose of this systematic review was to analyze the effect of plyometric jump training (PJT) applied in conjunction with tapering strategies on the jump performance of team-sport athletes. EVIDENCE ACQUISITION The meta-analysis included: 1) randomized-controlled studies that incorporated a PJT program; 2) cohorts of team-sport athletes; 3) jump performance assessments; and 4) studies that incorporated a programmed taper. A systematic search was conducted in distinct electronic databases for relevant studies. Aside from jump performance, the extracted data included characteristics of the participants, PJT, and tapering. Means and standard deviations were used to calculate the effect sizes (ES). To assess the effects of moderator variables, subgroup analyses were performed. The statistical significance level was set as P<0.05. EVIDENCE SYNTHESIS From 7020 records initially identified, 14 studies were eligible for meta-analysis. Across all included studies, there was a moderate, significant improvement in jump performance (ES=0.73; P<0.001). Additionally, the subgroup analysis demonstrated that the duration and intensity of the taper and the volume of the PJT induced similar improvements in jump performance (P<0.01). CONCLUSIONS In summary, PJT interventions that included a programmed taper induced significant improvements in jump performance in team-sport athletes. These effects were observed after different tapering strategies in terms of volume, taper duration, and the type of PJT prescribed.

Journal ArticleDOI
TL;DR: Tai Chi for 30 or 60 minutes five times weekly for 48 weeks improves the B MD of L2-4 and the femoral neck in older women, but does not affect the BMD of the greater trochanter and Ward's triangle.
Abstract: Background This study compared the effect of Tai Chi with the same frequency and different session duration on the bone mineral density (BMD) of older women Methods Healthy older women aged 55-70 years were randomly divided into the short-time group (N=17), long-time group (N=18), and control group (N=17) The BMD of L 2-4 and the proximal femur were measured at baseline and after 48 weeks of intervention Results From 0 to 48 weeks, the respective BMD values of L 2-4 and the femoral neck in the short-time and long-time groups increased by 88% and 75% (P 2-4 and the femoral neck was greater in the short-time and long-time groups than the control group (P Conclusions Tai Chi for 30 or 60 minutes five times weekly for 48 weeks improves the BMD of L 2-4 and the femoral neck in older women but does not affect the BMD of the greater trochanter and Ward's triangle Increasing the exercise duration does not increase the effect of Tai Chi on BMD

Journal ArticleDOI
TL;DR: The use of core training in combination with normal football training is shown to be effective in improving quickness and agility but not speed among young male football players after a period of eight weeks.
Abstract: BACKGROUND Core training effectively improves sport performance. The purpose of this study was to determine the effect of core training on the performance measures of speed, agility and quickness of U19 male football players. METHODS A total of 24 young male football players were divided into 12 in the experimental group (aged 18.17±0.72) and 12 in the control group (aged 18.31±0.75). The experimental group performed 30-35 min core training three days a week for eight weeks while the control group continued their routine training. Measurements included a 40-meter sprint test for speed, a hexagon test for quickness and an agility-T test for agility. Pre-test measurements at the start of the study and post-test measurements after eight weeks were compared by an ANOVA 2×2. A significant level of P<0.05 was established. RESULTS In the experimental group, there were an improvement in quickness (pre: 17.27±3.24"; post: 16.79±3.09"; P=0.005, η2=0.53) and agility (pre: 12.86±1.17"; post: 12.38±1.12"; P=0.003, η2=0.56), but the speed did not change (pre: 6.14±0.57"; post: 6.00±0.45", P=0.653). CONCLUSIONS The use of core training in combination with normal football training is shown to be effective in improving quickness and agility but not speed among young male football players after a period of eight weeks. So, it appears reasonable to include specific core training programs within football training.

Journal ArticleDOI
TL;DR: An overview of the injury incidence and incidence rates reported in the current literature as well as to assess the injury risks associated with CrossFit are provided.
Abstract: INTRODUCTION: Despite completing complex movements under cardiovascular and muscular fatigued conditions, CrossFit suggested safety of participants is one of the most important factors to consider. Therefore, the aim of this brief review is to provide an overview of the injury incidence and incidence rates reported in the current literature as well as to assess the injury risks associated with CrossFit. EVIDENCE ACQUISITION: Research papers were searched using the following databases: Scopus, SPORTDiscus, Web of Science, PubMed, and MEDLINE. The search identified 718 potential articles across all databases. After the application of inclusion criteria, a total of 14 articles were included in this review. EVIDENCE SYNTHESIS: The shoulder, spine, and knee are the most commonly injured areas in CrossFit. Injury incidence of each study ranges from 12.8-73.5% and reported injury rates ranging from 0.27-3.3/1000 training hours. CONCLUSIONS: Reported findings in the current literature would suggest CrossFit has a relatively low injury risk. The current review highlights three important factors associated with injury incidence and incidence rates in CrossFit: 1) training frequency, 2) duration of CrossFit experience, 3) individuals that compete in CrossFit competitions. Due to recall bias and selection bias further research is warranted over a longitudinal prospective study. Additionally, further research is needed to investigate mechanisms of injury and the relationship between training load and injury risk in CrossFit.

Journal ArticleDOI
TL;DR: It was identified that the concurrent approach had meaningful impacts on the fitness development of players and should be considered by coaches for future training interventions.
Abstract: Background The purpose of this study was twofold: 1) to characterize a common microcycle considering both internal and external training loads; and 2) to identify the effects of small-sided games (SSGs) and of power and strength training on the fitness status of football players. Methods Fifteen male football players (age: 18.55±0.39 years) participated in this study. Ninety-two consecutive training sessions were monitored and analyzed over a period of nineteen weeks. Rating of perceived exertion (RPE ) was used as an internal load marker, and the distances covered at different speed thresholds and accelerations/decelerations were used as external load markers to characterize the common microcycle. Participants' body composition, vertical jumping ability, maximal strength, speed, and agility were assessed twice before and after the training monitoring process. Results The results revealed that match day -5 (MD-5) and MD-1 were associated with the lowest RPE scores (4.2 and 3.8 A.U., respectively). MD-4 and MD-3 were associated with the highest RPE values (9.2 and 8.8 A.U., respectively). Meaningful changes in RPE were found between training days. External load monitoring revealed that MD-4 had the highest values of accelerations and decelerations >2 m/s2/min (4.22 and 3.17, respectively) and MD-3 had the highest values of distance covered at high intensity (6.11 m/s2/min). Meaningful moderate improvements in jumping performance (d=0.90) and maximal strength parameters (d=0.83) were also found between assessments. Conclusions It was identified that the concurrent approach had meaningful impacts on the fitness development of players and should be considered by coaches for future training interventions.

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TL;DR: CAF mouth rinse did not increase peak power (PP, mean power (MP), peak power relative to body mass (rel PP), mean powerrelative to bodymass (rel MP), fatigue index (FI) nor anaerobic contribution in the Wingate test.
Abstract: Background The purpose was to investigate the effect of caffeine (CAF) mouth rinse on peak power (PP), mean power (MP), peak power relative to body mass (rel PP), mean power relative to body mass (rel MP), fatigue index (FI) and anaerobic contribution in the Wingate Test. Methods Ten healthy men (age: 24.8±3.7 years; body mass: 71.0±7.8 kg; height: 170±3 cm; body fat: 17.02±4.9%; VO2max: 44.15±5.5 ml·kg-1·min=) were recruited. A randomized, double-blind, cross-over design was employed. Participants were instructed to complete Wingate Test in the fastest time possible under 2 conditions: CAF (25 ml of mint syrup with 1.2% of CAF, equivalent to 300 mg of CAF) and placebo (PLA) (25 ml of mint syrup without CAF). Results There was no difference at PP (P=0.66), MP (P=0.16), rel PP (P=0.82), rel MP (P=0.18), FI (P=0.19), anaerobic alactic (P=0.71), anaerobic lactic (P=0.25), total energy expenditure (P=0.41) and peak plasma lactate concentration (P=0.57). Conclusions CAF mouth rinse did not increase peak power (PP), mean power (MP), peak power relative to body mass (rel PP), mean power relative to body mass (rel MP), Fatigue Index (FI) nor anaerobic contribution in the Wingate Test.

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TL;DR: Only ischemic preconditioning group improved performance time and decreased heart rate at submaximal point during incremental cycling test, and promoted faster heart rate recovery, mainly on first minute.
Abstract: Background Previous studies have assessed the effects of ischemic preconditioning (IPC) on exercise performance and physiological variables, such as lactate and muscle deoxygenation In this study, we verified the IPC effects on heart rate and performance during and immediately after a maximal incremental cycling test Methods Eighteen recreationally trained cyclists (28 ± 4 years) were allocated to one of three groups: IPC, SHAM and Control After the first visit to familiarization, cyclists attended the laboratory on two separate occasions to perform an incremental cycling test: in the 1st visit they performed the reference test (baseline), and in 2nd the test ischemic preconditioning (2 cycles of 5-min occlusion [at 50 mm Hg above systolic arterial pressure]/ 5-min reperfusion), SHAM (identical to ischemic preconditioning, but at 20 mm Hg) or control (no occlusion) interventions (post intervention) During the incremental cycling test, heart rate, power output and perceived exertion were measured and the heart rate was monitored throughout the recovery Results Only ischemic preconditioning group improved performance time by 49 ± 40% and decreased heart rate at submaximal point during incremental cycling test, of 170 ± 8 to 166 ± 8 bpm (p Conclusions Two cycles of five minutes of ischemia were relevant to produce positive effects on performance and alter the heart rate during and soon after incremental cycling test

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TL;DR: High intensity exercise results in greater muscle damage in both trained and untrained individuals vs. low intensity exercise, however untrained participants experience more pain and with earlier onset and should therefore take caution when beginning exercise programs that require consecutive sessions of high intensity exercise.
Abstract: BACKGROUND Individuals participating in exercise beyond their level of fitness may be at higher risk for exercise-induced muscle damage, however the impact of training status on muscle damage development is not well understood. The purpose of this study was to measure skeletal muscle damage and soreness after five days of high and low intensity exercise in previously trained and untrained individuals. METHODS Eighteen males and females (9 trained and 9 untrained) completed five consecutive days of high intensity (HI) exercise and five consecutive days of low intensity (LI) exercise. Blood was drawn at the initial visit and after completion of each exercise intensity period. RESULTS CK was elevated post exercise for both groups during both intensities, but was greater in trained vs. untrained (HI: 203.6 vs. 143.4 IU/L and LI: 156.4 vs. 109.3 IU/L; P<0.01). Myoglobin was significantly higher after exercise for both groups (P<0.01) and was higher following high vs. low intensity in trained (P<0.01), but not untrained (P=0.052). Untrained experienced soreness following one day of high intensity exercise vs. after 3 days in trained participants (P=0.04, P=0.02). CONCLUSIONS The current study suggests that high intensity exercise results in greater muscle damage in both trained and untrained individuals vs. low intensity exercise. However untrained participants experience more pain and with earlier onset and should therefore take caution when beginning exercise programs that require consecutive sessions of high intensity exercise.

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TL;DR: Despite the expected weight increase, the creatine monohydrate supplementation is safe for health and no detrimental effects on different organs and physiological systems were observed in the cohort of volunteers.
Abstract: Background Creatine represents a natural supplement and ergogenic aid for sport performance, but there are several concerns regarding its safety for health The present double-blind placebo-controlled study evaluated the effect of creatine monohydrate supplementation on a panel of blood and urine health indicators in resistance training practitioners Methods Eighteen males performing resistance training three times per week were supplemented with 03 g/kg per day creatine monohydrate for 7 days and compared with matched controls supplemented with dextrosol Blood and urine samples were collected pre- and 30 days post-supplementation to evaluate 41 biochemical parameters and renal function Results Creatine monohydrate supplementation did not cause adverse events and, as expected, promoted an increase of the performance and body weight No modification of red blood cells parameters, white blood cells profile, blood lipid profile, metabolic and urine markers, hepatic and renal function were observed in the supplemented group Conclusions Despite the expected weight increase, the creatine monohydrate supplementation is safe for health and no detrimental effects on different organs and physiological systems were observed in our cohort of volunteers

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TL;DR: Investigation of the relationship between muscle strength (MS) and clusters of metabolic syndrome (MetS) components in adults from Florianópolis, Brazil found greater number of individual MetS components were related to lower MS values.
Abstract: Background Cardiovascular diseases are the leading cause of death globally. The aim of the study was to investigate the relationship between muscle strength (MS) and clusters of metabolic syndrome (MetS) components in adults. Methods Population-based cross-sectional study comprising 533 adults (45.3±11.1 years) from Florianopolis, Brazil. MS - calculated as the ratio between absolute strength (kgf) and body mass (kg) - was measured by handgrip dynamometry. Data on blood pressure, waist circumference, lipids and blood glucose were used to identify MetS components that were analyzed as individual variables and clusters. Multiple linear regression adjusted was used. Results Individually, MS was inversely associated with all MetS components (1, 2, 3 and 4 factors, β of at least -0.08 kgf/kg). In addition, MS was negatively associated with number of positive MetS components (1, 2, 3 and 4 factors; β of at least -0.05 kgf/kg). Individually or combined in clusters of two, three and four risk factors (β of at least -0.20 kgf/kg), abdominal obesity was directly associated with lower MS values. All combinations of 3 and 4 MetS components (β of at least -0.13 kgf/kg) were inversely associated with MS. Conclusions Greater number of individual MetS components were related to lower MS values.

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TL;DR: The results showed that the effect of a 4-week plyometric training program on RSI and leg stiffness is sport dependent and the applied plyometric program was effective in reducing ground contact time and therefore increasing leg stiffness.
Abstract: Background Plyometric exercises are often used to develop lower limb strength and performance-related biomechanics such as leg stiffness However, the effectiveness of plyometric training may depend on participants' own training and performance demands The purpose of this study was to examine the effect of plyometric training on Reactive Strength Index (RSI) and leg stiffness (Kleg) on young athletes of different sports Methods Forty eight female athletes (25 Taekwondo (TKD) and 23 rhythmic gymnastics (RG), mean±SD: age: 894±250 years; mass: 2973±769 kg; height: 13884±1190 cm; training experience: 462±237 years) participated in this study Participants were randomly assigned to experimental (PT, N=24) and control (CG, N=24) groups The PT group followed a twice-weekly plyometric training program for 4 weeks Plyometric drills lasted approximately 5-10 s, and at least 90 s rest was allowed after each set To examine RSI, participants performed trials of five maximal CMJs Submaximal hopping (20 hops) was performed in order to examine leg stiffness Results Significant interaction effect was found for RSI and the post hoc analysis showed that RSI significantly increased by 35% (P=0017) in RG athletes, whereas a significantly reduction by 28% (P=0004) was revealed in TKD athletes The interaction effect between time and group was statistically significant for Kleg (P 005) in RG athletes Conclusions The results showed that the effect of a 4-week plyometric training program on RSI and leg stiffness is sport dependent Further, the applied plyometric program was effective in reducing ground contact time and therefore increasing leg stiffness

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TL;DR: Ankle dorsiflexion ROM is still reduced 48h after a competitive basketball match in semi-professional basketball players, and the implementation of specific recovery strategies aiming at minimizing a decrease in ankle dors iflexion after a match might be considered to reduce the likelihood of ankle injury.
Abstract: Background The aim of this study was to investigate the effects of basketball match-play on ankle dorsiflexion range of motion (ROM) and countermovement (CMJ) performance, and their association with internal match load. Methods Thirty semi-professional basketball players participated in this study. Ankle dorsiflexion ROM and bilateral CMJ performance were evaluated before (pre-match) and immediately after match-play (post-match). In addition, ankle dorsiflexion ROM was measured 48 hours post-match. Furthermore, for each player, the ankle dorsiflexion ROM scores were categorized as normal or restricted according to previously reported reference values (>2 cm change from baseline pre-match to post-match and to 48 hours post-match). Results Ankle dorsiflexion ROM was increased post-match from pre-match in dominant and non-dominant limbs (most likely small) and decreased 48 hours post-match (most likely moderate) compared with immediately post-match measures in both limbs. Approximately 20% of all players showed restricted ankle dorsiflexion ROM values 48 hours post-match. CMJ performance was higher post-match than pre-match. Conclusions Ankle dorsiflexion ROM is still reduced 48 h after a competitive basketball match in semi-professional basketball players. The implementation of specific recovery strategies aiming at minimizing a decrease in ankle dorsiflexion after a match might be considered to reduce the likelihood of ankle injury.