High-intensity Movements Research Articles

Free-Living Motor Activity Monitoring in Ataxia-Telangiectasia.

With disease-modifying approaches under evaluation in ataxia-telangiectasia and other ataxias, there is a need for objective and reliable biomarkers of free-living motor function. In this study, we test the hypothesis that metrics derived from a single wrist sensor worn at home provide accurate, reliable, and interpretable information about neurological disease severity in children with A-T.A total of 15 children with A-T and 15 age- and sex-matched controls wore a sensor with a triaxial accelerometer on their dominant wrist for 1 week at home. Activity intensity measures, derived from the sensor data, were compared with in-person neurological evaluation on the Brief Ataxia Rating Scale (BARS) and performance on a validated computer mouse task.Children with A-T were inactive the same proportion of each day as controls but produced more low intensity movements (p < 0.01; Cohen’s d = 1.48) and fewer high intensity movements (p < 0.001; Cohen’s d = 1.71). The range of activity intensities was markedly reduced in A-T compared to controls (p < 0.0001; Cohen’s d = 2.72). The activity metrics correlated strongly with arm, gait, and total clinical severity (r: 0.71–0.87; p < 0.0001), correlated with specific computer task motor features (r: 0.67–0.92; p < 0.01), demonstrated high reliability (r: 0.86–0.93; p < 0.00001), and were not significantly influenced by age in the healthy control group.Motor activity metrics from a single, inexpensive wrist sensor during free-living behavior provide accurate and reliable information about diagnosis, neurological disease severity, and motor performance. These low-burden measurements are applicable independent of ambulatory status and are potential digital behavioral biomarkers in A-T.

Resting Energy Expenditure in CrossFit® Participants: Predictive Equations versus Indirect Calorimetry

Background: CrossFit® involves high-intensity functional movements and research has shown that the program increases metabolic rates in participants. Objective: To measure resting energy expenditure (REE) in CrossFit® participants using indirect calorimetry (IC) and to verify the most appropriate predictive equation to estimate REE. Methods: Overall, 142 CrossFit® participants (18–59 years; 91 [64.1%], women) underwent weight, height, waist circumference, and body mass index (BMI) measurements. Body composition was evaluated using a portable ultrasound system (BodyMetrix®). REEs were measured (mREE) by IC and predicted by six different equations (pREE): Harris-Benedict, World Health Organization (WHO), Henry and Rees, Cunningham (1980 and 1991), and Mifflin–St. Jeor. Results: The mean age was 33.0 (6.3) years, with no significant difference between men and women; mean mREE, 1583.2(404.4) kcal/d; and pREE, 1455.5(230.9) to 1711.3(285.5) kcal/d. The best REE predictive equations for this population were Cunningham (1991) (P=0.338), WHO (P=0.494), and Harris-Benedict (P=0.705) equations. The Harris-Benedict equation presented a smaller difference compared with IC [12.9(307.6) kcal], the Cunningham (1991) equation showed improved adequacy (102.5%), and the WHO equation presented highest accuracy (59.9%). The equations that were closest to the mREE were the Harris-Benedict for women and the WHO equation for men. Conclusion: Therefore, for CrossFit® participants, the REE can accurately be predicted with the Cunningham (1991), WHO, and Harris-Benedict equations.

Kinematika Sendi Lengan Penari Bapang Malangan

&#x0D; &#x0D; &#x0D; &#x0D; Dancers experience various injuries, because dancing requires high intensity movements. Frequent injuries to dancers involve overuse of joints and muscles. The highest potential for injury is in the knee. However, in the Bapang Malangan Dance, the arms are the limbs that are often used in extreme movements. Thus the potential for injury can be high. This study focuses on the kinematics of arm movement of the Bapang Malangan Dance in relation to the possibility of injury. The research was carried out through analyzing image data resulting from the rendering of dance video footage, following a kinematics-based biomechanical framework and engineering dynamics. The results showed that the kinematic analysis of the Bapang dancer's arm was depicted only on the change in position because velocity and velocity could not be measured directly. Changes in the position of the Bapang dancer's arms can be depicted in graphic form through frame analysis of the transformed video files into image files. The arm joints that get a lot of weight are the shoulder and elbow joints, which in Bapang Malangan dancers have the potential to experience injury due to tugging and twisting. The complexities of movements and changes in dancer movements turn out to make it difficult to determine the speed and acceleration by analyzing the rendered images. A measuring instrument is needed that can directly measure arm movements when dancing. This tool must not use cables so as not to obstruct the dance movement.&#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; Keywords: biomechanic, kinematic, arm joint, dancer, Bapang Malangan&#x0D; &#x0D; &#x0D; &#x0D;

Facial Fractures Related to Soccer.

Soccer is one of the most popular sports in the world. Despite the concept that soccer is not a violent game, it can lead to several injuries in amateur and professional settings, including facial fractures. Previous studies of facial fractures in soccer were all retrospective and, to date, no prospective studies are available in the literature.The authors performed a comprehensive literature search using the terms "soccer" AND "facial fracture" OR "craniofacial fracture" and "football" AND "facial fracture" OR "craniofacial fracture" and retrieved 693 articles. After applying inclusion and exclusion criteria, 11 articles were included in the present study.A total of 647 patients had suffered facial trauma, with a male-to-female ratio of 63.7:1. The patients' mean age was 27.3 years.The articles reported 670 fractures as follows: 219 (32.7%) in the zygoma, 197 (29.4%) in the nasal bone, 153 (23.6%) in the mandibula, 54 (8.0%) in the orbital wall, 12 (1.8%) in the frontal sinus, 10 (1.5%) in the alveolar bone, 3 (0.4%) in the maxilla, 3 (0.4%) in a Le Fort pattern, and 1 (0.1%) in a naso-orbito-ethmoid (NOE) pattern.Sports are a frequent cause of maxillofacial trauma and are responsible for 9.2% to 33.2% of such injuries. Soccer is a contact sport more associated with lower-limb injuries, but with a significant rate of facial fractures. As soccer is a popular sport played without facial protection and involving high-intensity movements and contact, the prevention of facial fractures related to this sport is crucial to improve the players' safety.

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

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

Injury rate among CrossFit participants and its associated risk factors in Riyadh: A cross-sectional study

Background: CrossFit is a form of exercise that incorporates rapid and successive high-intensity movements. This study assesses the rate and risk factors of CrossFit injuries. Materials and Methods: This is an analytical, cross-sectional study that was conducted in four CrossFit affiliates (two for males and two for females) in Riyadh, Saudi Arabia. A validated questionnaire was used to collect the data from CrossFit athletes between January and April 2018. Data collected were incidence, severity, number of injuries, and potential risk factors for injury in the preceding 6 months. Using the SPSS software, data were analyzed using the t-test, Chi-square test, and multivariate logistic regression. Results: Among the 255 participants, 31.37% had an injury during the last 6 months' period. The incidence rate of injury was 3.33/1000 athlete hours. Participants who did not include cool down in their CrossFit workout were significantly more likely to be injured (41.58% vs. 24.68%, P = 0.004). Injured participants reported higher weekly athlete training hours (5.73 ± 3.89 vs. 4.55 ± 2.94, P = 0.008). Most of the participants' injuries were acute and required medical attention (51%). Conclusion: Injury rate among CrossFit athletes in Saudi Arabia is relatively high, especially among those who train regularly and those who do not incorporate cool-down in their CrossFit regimen. Cooling-down after CrossFit activities might help in reducing the rate of injury.

Metabolic load comparison between the quarters of a game in elite male basketball players using sport metabolomics

Purpose: A basketball match is characterized by intermittent high-intensity activities, thereby relying extensively on both aerobic and anaerobic metabolic pathways. Here, we aimed to compare the metabolic fluctuations between the four 10-min quarters of high-level basketball games using metabolomics analyses. Methods: 70 male basketball players with at least 3 years of experience in the Iran national top-league participated. Before and after each quarter, saliva samples were taken for subsequent untargeted metabolomics analyses, where Principal component analysis (PCA) and Partial least squares-discriminant analysis (PLS-DA) were employed for statistical analysis. Results: Quarters 1 and 3 showed similar metabolic profiles, with increased levels of ATP turnover (higher Lactate, Pyruvate, Succinic Acid, Citric Cid, Glucose and Hypoxanthine), indicating more reliance on anaerobic energy systems than quarters 2 and 4. In comparison, quarters 2 and 4 showed a reduction in Valine and Lucien and an increase in Alanine, Glycerol, AcetoAcetic Acid, Acetone, Succinic Acid, Citric Acid, Acetate and Taurine that was not present in quarters 1 and 3, indicating greater reliance of aerobic energy contribution, fat metabolism and gluconeogenesis. Conclusion: Our data demonstrate that the higher intensity of movements in the first quarter, where players are more rested, induce an increase in anaerobic energy contribution. This seems to be the case also for the third quarter that follows 15 min of rest, whereas the accumulated fatigue and reduction of high-intensity movements in the second and fourth quarters also reduces the speed of energy production and players thereby utilize more aerobic energy.

Comparative and correlational analysis of the performance from 2016 crossfit games high-level athletes

Background: CrossFit is a functional training modality created by Greg Glassman in 1995 in the United States. Such modality is characterized by the execution of complex and high intensity movements with the purpose of preparing the participant for the unpredictable. It is observed the exponential increase in CrossFit practice across the world, with this increase there are a consolidation of this modality with as a very peculiar sport modality, since as tasks to be performed in the competitions are made public just before the events happen. Few studies have focused on the determinants of competitive success in CrossFit, both morphologically and performance. Objective: This present study dedicated to investigate, in the existing literature and in the results of the 2016 championship, variables that can be predicted the performance of these athletes. Methods: The performance of 40 2016 - CrossFit Games finalists of both genders were analyzed in the morphological variables (weight, height, body mass index), performance and specific tests (Benchmarks and 1 MR tests). Results: We found that among male athletes, it was not possible to identify variables that could predict a classification. However, among the women, we identified some variables that correlated with classification, such as the Benchmark Filth 50, Sprint performance of 400m and maximal loads in the Clean and Jerk and Snatch exercises. Conclusion: It was attributed to the correlations found among women the smaller participation in the Games, this allowed physical characteristics as force to influence in the final position.

Acceleration Profile of High-Intensity Movements in Basketball Games.

Koyama, T, Rikukawa, A, Nagano, Y, Sasaki, S, Ichikawa, H, and Hirose, N. Acceleration profile of high-intensity movements in basketball games. J Strength Cond Res 36(6): 1715-1719, 2022-This study aimed to elucidate movements that require greater acceleration during basketball games, their occurrence frequency, and compare acceleration components. Eighteen male collegiate basketball players (age: 19.5 ± 0.8 years) were enrolled. Triaxial accelerometer was used to measure acceleration and a synchronized video was recorded. Moments that generated resultant accelerations >4, 6, and 8 G, and their coincided movements were identified. Ratios and frequencies of the extracted movements were calculated and Jonckheere-Terpstra trend test was used to examine which movement rate increased when acceleration threshold increased. In addition, the top 7 movements that generated a resultant acceleration >6 G among the combination of basketball-specific movements were extracted. Their resultant, mediolateral, vertical, and anteroposterior accelerations were identified and compared using one-way analysis of variance. Cohen's d was used to calculate effect sizes. All p < 0.05 were considered statistically significant. The extracted frequencies were 33.6, 9.1, and 2.3 cases per minute for >4 G, >6 G, and >8 G, respectively. As the threshold increased, the rate of deceleration, landing, and physical contact increased. The mediolateral acceleration of physical contact was significantly greater than other movements, whereas the vertical acceleration of landing and deceleration was significantly greater than other movements. Thus, acceleration component analysis was performed to classify movement types. Greater acceleration appeared frequently in movement during defense. It is suggested that many defense movements involve a reaction to the ball and opponent. There are many passive movements during defense and speed changes rapidly. If many passive movements occur when defending, larger physical load is applied, and may lead to fatigue.

Maximum Movement Workloads and High-Intensity Workload Demands by Position in NCAA Division I Collegiate Football.

Sanders, GJ, Roll, B, Peacock, CA, and Kollock, RO. Maximum movement workloads and high-intensity workload demands by position in NCAA Division I collegiate football. J Strength Cond Res 34(7): 1974-1981, 2020-The purpose of the study was to quantify the average and maximum (i.e., peak) movement workloads, and the percent of those workloads performed at high intensity by NCAA Division I football athletes during competitive games. Using global positioning system devices (Catapult Sports), low, moderate, and high and total multidirectional movement workloads were quantified by each position. Strategically achieving maximal workloads may improve both conditioning and rehabilitation protocols for athletes as they prepare for competition or return to play after an injury. A total of 40 football athletes were included in the analysis. For the data to be included, athletes were required to participate in ≥75% of the offensive or defensive snaps for any given game. There was a total of 286 data downloads from 13 different games for 8 different football positions. Data were calculated and compared by offensive and defensive position to establish the mean, SD, and maximum workloads during competitive games. The percent high-intensity workload profile was established to assess the total number and percent of high-intensity movement workloads by position. The profile was calculated by dividing a position's maximal high-intensity movement workload by the total (e.g., sum of maximal low, moderate, and high-intensity movements) movement workload. One-way analysis of variances revealed that there was a main effect of football position for total movement workloads and the percent of workloads performed at high intensities (p ≤ 0.025 for all). Maximal high-intensity workloads were 1.6-4.3 times greater than average high-intensity workloads, and the percent of total workloads performed at high intensities varied greatly by position. Strategically training for and using maximal movement workloads can help ensure that athletes are achieving workloads that are similar to the greatest demands of a competitive game.

Effect of ginger on the lower limb anaerobic power of brazilian national team gymnasts

Introdução: a ginástica aeróbica é um esporte que tem crescido consistentemente nas últimas décadas, e sua prática exige que seus atletas realizem movimentos complexos e de alta intensidade. Objetivo: analisar se a suplementação com gengibre tem efeito ergogênico no poder anaeróbico dos membros (PAMI) em atletas de ginástica aeróbica. Métodos: foi realizado um estudo randomizado, duplo-cego, controlado por placebo, com nove atletas (23,11 + 4,14 anos, 1,63 + 0,09 m, 60,51 + 7,38 kg) da Seleção Brasileira de Ginástica Aeróbica. Após a ingestão de 400 mg de Zingiber officinale ou placebo por sete dias, os indivíduos foram submetidos a um teste de potência anaeróbica (RAST). Os dados de Velocidade de pico e Potência de pico (m/s e W), potência média e mínima (W) e índice de fadiga (W/s e %) foram obtidos no RAST. Resultados: Após verificar a não normalidade da amostra, foi aplicado o Mann-Whitney, mas não foram encontradas diferenças significativas na velocidade de pico da suplementação de gengibre (6,28 ± 0,41 m / s; 445,28 ± 117,15 W) em comparação ao placebo (6,22 ± 0,45 m / s; 425,95 ± 130,39 W). Conclusões: conclui-se que a ingestão de 400 mg de Z. officinale não exerce efeito ergogênico no poder anaeróbico dos membros inferiores de atletas de ginástica aeróbica.

Effectiveness of a crossover prosthetic foot in active children with a congenital lower limb deficiency

Children with lower limb prostheses cannot always keep up with their peers during active play. A pediatric crossover foot may be a promising prosthetic alternative for children engaging in high-intensity movements necessary for active play. To compare children's walking performance, running performance, experienced competence, and cosmesis using their prescribed prosthesis compared with the crossover foot. Pretest-posttest study. Children with lower limb amputation or deficiency were recruited. Measurements were taken at baseline with the prescribed prosthesis and 6 weeks later with the crossover foot. Walking speed, energy cost of walking, anaerobic muscle power, stair climbing speed, ankle power, and cosmesis were evaluated. Four children participated in the study. Two children had increased walking speed with the same energy cost, one child had decreased speed with increased energy cost, and one child had the same speed with decreased energy cost. Muscle power increased for three of the four children and ankle power increased for all children while using the crossover foot compared to the prescribed prosthesis. Two children reported knee pain or feeling excessive knee flexion when running with the crossover foot. One child reported negative feelings toward cosmesis of the crossover foot. This study suggests crossover foot may benefit active children by improving walking and running performance, and decreasing energy cost. However, knee pain reports or negative feelings toward the atypical design suggest the crossover foot may not be ideal for every child. Further research is needed to determine which pediatric users would benefit from this type of prosthetic foot. Children with lower limb deficiencies are active prosthetic users who often switch between low- and high-intensity movements in their daily activities. Therefore, they might benefit from a crossover prosthetic design. The preliminary findings of this study suggest the crossover foot (XF) may be a promising foot for active children.

Anaerobic performance among children with spina bifida.

Children and adolescents with spina bifida demonstrate less physical activity. Most of them are wheelchair users. It is important to control their physical fitness for instance their anaerobic performance. They need anaerobic performance to daily activities like transfers that require short and high intensity movements. The aim of this study was to assess anaerobic performance among children with spina bifida and to evaluate their results in relation to normative values from able-bodied peers, as well as to find appropriate, easy and feasible field-based tests measuring anaerobic performance of children with spina bifida in non-laboratory settings. Ninety-five children and adolescents with spina bifida were divided according to gender and age (four male and four female groups) and performed the 30-second Wingate Anaerobic Test (WAnT), the handgrip test and the chest pass test. The Kolmogorov-Smirnov test, the Kruskal-Wallis test, the Mann-Whitney U-test, the Pearson correlation (P<0.05) and Effect Size were applied in this study. Differences in MP, PP, rMP and rPP between age groups were found. A significant and strong correlation of the 30-second WAnT results (MP, PP) with the handgrip test and the chest pass test was found (P<0.01; r>0.7). In conclusion, anaerobic performance of children with spina bifida varies depending on the age group and is "very poor" compared to anaerobic performance of their able-bodied peers. The chest pass test may be a good non-laboratory test to be used to indirectly assess anaerobic performance of children with spina bifida.

Evaluation of the effects of traction on ankle kinematics during a side cut using bfPCA

High-intensity movements and sudden changes of direction in football are known to contribute to the occurrence of non-contact injuries (Jain, Murray, Kemp, & Calder, 2014). Studies of ankle injury ...

A comparison of the physical demands of a one-day cricket game and the training sessions of provincial cricket players using Global Positioning System tracking software

Background: Cricket is a highly technical skills-based game and coaches consequently focus on the improvement of skills during training sessions. However, a certain level of physical fitness is required to execute these skills optimally. Coaches tend to give little focused attention to the development of physical fitness during training, which could lead to players being physically unprepared for the demands of a game. &#x0D; Objective: The purpose of this study was to assess and compare the physical demands of a one-day cricket game and a training session of provincial cricket players, using Global Positioning System units. &#x0D; Methods: Nineteen male provincial cricketers participated in the research. The participants were classified into five sub-disciplines, namely, batting, fast bowling, spin bowling, fielding and wicketkeeping. The study employed a descriptive and comparative design as it essentially collected numerical data from Global Positioning System units to describe and compare the physical demands of a one-day game of cricket and a training session preceding these games. The variables used in the study included total distances travelled in the game which were divided into five movement categories, i.e. walking, jogging, running, striding and sprinting. Also included were average and maximum heart rates, number of sprints and average sprint distances. &#x0D; Results: There were significant differences across all sub-disciplines and movement categories during training and the one-day game for provincial cricket players. Batsmen showed the greatest discrepancies between training and the game for all high-intensity movements (p&lt;0.05). &#x0D; Conclusion: The findings of this study highlight the different physical and physiological demands placed on players in the various sub-disciplines during training and the one-day game. The current study found the major disparity between training and the one-day game was amongst the batsmen.

TORQUE, POWER AND FATIGUE RATIO IN KNEE FLEXORS AND EXTENSORS OF SOCCER PLAYERS

ABSTRACT Introduction: Soccer is the most popular and practiced sport in the world and is characterized by high intensity movements. This high demand induces several types of locomotor system injury, and one of the intrinsic factors responsible for triggering these injuries is muscle imbalances, which can occur between limbs or between muscles groups of the same limb. Objective: To evaluate the muscular performance between knee flexor/extensor groups of both limbs in professional soccer athletes.: Methods: Isokinetic assessments were performed in 18 professional soccer athletes, with mean age of 26.9 ± 3.6 years and mean body mass index (BMI) of 23.9 ± 1.7 kg/m2.. The test protocol consisted of five concentric contractions of knee flexion and extension at angular velocity of 60o/sec, 15 contractions at 180o/sec and 30 contractions at 300o/sec in both limbs. Test paired t-test was used to verify the torque, power, and fatigue ratio of flexors and extensors of the dominant and non-dominant knee. Results: There was no significant difference between the evaluated members related to dominance (p&gt;0.05). Regarding the torque ratio between flexors and extensors, we observed values below what is considered normal for this population, besides a higher fatigue index in knee flexor group when compared with the extensor group. Conclusion: No better performance was observed in the dominant limb, suggesting that, although this limb is preferred, this does not necessarily characterizes the better performance. The data also revealed an imbalance in the torque production capacity between the knee flexor and extensor groups, with an unfavorable ratio for the hamstrings, as well as a higher fatigue index in this group, which would make these muscles more susceptible to injures. Level of Evidence II; Diagnostic studies - Investigating a diagnostic test.

Monitoring and Managing Fatigue in Basketball.

The sport of basketball exposes athletes to frequent high intensity movements including sprinting, jumping, accelerations, decelerations and changes of direction during training and competition which can lead to acute and accumulated chronic fatigue. Fatigue may affect the ability of the athlete to perform over the course of a lengthy season. The ability of practitioners to quantify the workload and subsequent fatigue in basketball athletes in order to monitor and manage fatigue levels may be beneficial in maintaining high levels of performance and preventing unfavorable physical and physiological training adaptations. There is currently limited research quantifying training or competition workload outside of time motion analysis in basketball. In addition, systematic research investigating methods to monitor and manage athlete fatigue in basketball throughout a season is scarce. To effectively optimize and maintain peak training and playing performance throughout a basketball season, potential workload and fatigue monitoring strategies need to be discussed.

The Impact of Load Carriage on Measures of Power and Agility in Tactical Occupations: A Critical Review.

The current literature suggests that load carriage can impact on a tactical officer’s mobility, and that survival in the field may rely on the officer’s mobility. The ability for humans to generate power and agility is critical for performance of the high-intensity movements required in the field of duty. The aims of this review were to critically examine the literature investigating the impacts of load carriage on measures of power and agility and to synthesize the findings. The authors completed a search of the literature using key search terms in four databases. After relevant studies were located using strict inclusion and exclusion criteria, the studies were critically appraised using the Downs and Black Checklist and relevant data were extracted and tabled. Fourteen studies were deemed relevant for this review, ranging in percentage quality scores from 42.85% to 71.43%. Outcome measures used in these studies to indicate levels of power and agility included short-distance sprints, vertical jumps, and agility runs, among others. Performance of both power and agility was shown to decrease when tactical load was added to the participants. This suggests that the increase in weight carried by tactical officers may put this population at risk of injury or fatality in the line of duty.

Bone Mineral Monitoring with Dual-energy X-ray Absorptiometry (DEXA) in University Female Soccer Players

Soccer practice usually has high intensity movements involving sprints and change of direction; these implicate great strength over the bone structure having influence in the bone mineral since they facilitate bone stimulation, getting the appropriate parameters. Several studies show soccer practice or training, amateur as well as professional, lead to effective adaptations in the bone mass, as well as increases in bone mineral content (BMC) and bone mineral density (BMD). PURPOSE: The evaluation of changes in BMC and BMD during 4-month period, competition training of university, female, soccer players. METHODS: Body measurements were made at the beginning and at the end of 4-month training to 19 soccer players (20.87 ± 1.88 years old), through DEXA where BMC and BMD of arm, leg, trunk and total body were obtained. They were evaluated fasting at the morning, where every subject used a minimum of clothes for measurement. They also received informed consent explaining the test protocol, after that their height was measured. For the statistical analysis, the software SPSS version 21.0 was used. The Pearson product-moment correlation coefficient method was used. RESULTS: Meaningful increases were found from the initial take to the final take of BMC of arms and legs (p<0.01), and meaningful decrease on trunk and total body (p<0.01). Regarding BMD, significant increases were seen in legs and trunk (p<0.01), however in total body obtained a significant decrease (p<0.01) and not significant in arms (p=0.252), all of this during a 4-month study. CONCLUSIONS: Significant changes of lower limbs BMC and BMD are associated to the impact of kicking the ball, the sprints and the jumps that exist in soccer practice.

Low-Carbohydrate-High-Fat Diet: Can it Help Exercise Performance?

Low-carbohydrate-high-fat (LCHF) diets have been used as a means of weight loss and control of symptoms in several clinical conditions. There is emerging evidence that the metabolic changes induced by LCHF diets enhance endurance performance. The aims of this review are to examine the evidence of LCHF diets in improving various aspects of athletic performance. Long-term LCHF dietary intake may help control body weight and fat mass while maintaining lean body mass in athletes in weight-sensitive sports. LCHF-adapted endurance athletes can reach the maximal fat oxidation rate of approximately 1.5 g/min, with a lower carbohydrate oxidation rate and similar muscle glycogen content and a resynthesis rate compared to their counterparts consuming high-carbohydrate-low-fat (HCLF) diets. The elevated fat oxidation rate and glycogen sparing effect may improve performance in ultra-endurance events. These metabolic changes may also prevent the decline in performance in later stages of repeated high-intensity movements, in which the aerobic metabolism becomes more important. However, elevated blood concentrations of non-esterified fatty acids and ammonia during exercise after LCHF diets may lead to early development of central fatigue. It appears that at least several months of adaptation to a LCHF diet are required for the metabolic changes and restoration of muscle glycogen to occur. Further investigations on LCHF diets are needed regarding (1) performance after weight loss in weight-categorized sports; (2) repeated high-intensity exercise performance; (3) development of central fatigue during endurance events; (4) perceptual-motor performance during prolonged intermittent sports; and (5) ideal dietary fatty acid compositions.