A Single Dose of Beetroot Juice not Enhance Performance during Intervallic Swimming Efforts.

Despite the numerous scientific evidence on the topic, there is no clear and consistent answer that clarifies the true effects of beetroot juice (BJ) supplementation on different types of physical performance. This study examined whether an acute intake of BJ improves swimming performance, physiological variables of anaerobic metabolism, or subjective measures during high-intensity interval exercise with incomplete rest in competitive swimmers. Eighteen competitive swimmers (nine females and nine males) participated in this cross-over randomized, placebo-controlled, double-blind and counterbalanced study. In two trials, swimmers ingested BJ (70 mL, 6.4 mmol/400 mg NO3-) or placebo (PLA) (70 mL, 0.04 mmol/3 mg NO3-) three hours before a 2×6×100 m maximal effort with 40 seconds rest between repetitions and three minutes between blocks. The 100 m times showed no differences between groups (p > 0.05), but there was an interaction between block×repetition×condition (F5 = 3.10; p = 0.046; ηp2 = 0.54), indicating that the BJ group decreased the time of the sixth repetition of block2 compared to block1 (p = 0.01). Lactate concentration showed no differences between conditions (p > 0.05), but there was a main effect of block (ηp2 = 0.60) and a block×repetition interaction (ηp2 = 0.70), indicating higher values in block2 and increasing values between repetitions in block1. The subjective scales, perception of exertion (RPE) and Total Quality Recovery (TQR), showed no effects of condition (p > 0.05), but BJ swimmers had a greater TQR in the last repetitions of each block. In conclusion, a single dose of BJ did not enhance intermittent swimming performance or modified the physiological (lactate and heart rate) or subjective (RPE and TQR) variables; although there was a possible positive effect on the exercise tolerance at the end of effort.

Internal workload in elite female football players during the whole in-season: starters vs non-starters.

The aim of this study was to quantify weekly internal workload across the in-season and compare the workload variables between starter and non-starter Spanish female first league (Liga Iberdrola) football players. Twenty-six participants belonging to the same team (age, height, and mass: 25.4 ± 6.1 years, 167.4 ± 4.8 cm and 57.96 ± 6.28 kg, respectively) participated in this study. Training loads (TL) and match loads (ML) were assessed through breath-cardiovascular (RPEbreath), leg-musculature (RPEleg) and cognitive (RPEcog) rating of perceived exertion (RPE0-10) for each training session and match during the in-season phase (35 weeks). Session-RPE (sRPE) was calculated by multiplying each RPE value by session duration (minutes). From these, total weekly TL (weekly TL+ML), weekly TL, weekly ML, chronic workload, acute:chronic workload ratio, training monotony, and training strain were calculated. Linear mixed models were used to assess differences for each dependent variable, with playing time (starter vs non-starter players) used as a fixed factor, and athlete, week, and team as random factors. The results showed that total weekly TL (d = 1.23-2.04), weekly ML (d = 4.65-5.31), training monotony (d = 0.48-1.66) and training strain (d = 0.24-1.82) for RPEbreath, RPEleg and RPEcog were higher for starters in comparison with non-starters (p = 0.01). Coaches involved in elite female football should consider implementing differential sRPE monitoring strategies to optimize the weekly load distribution for starters and non-starters and to introduce compensatory strategies to equalise players' total weekly load.

Beetroot juice ingestion does not improve neuromuscular performance and match-play demands in elite female hockey players: a randomized, double-blind, placebo-controlled study.

PURPOSE: Beetroot juice is a dietary supplement that contains high levels of inorganic nitrate (NO3-) and that its intake has proven effective at increasing blood nitric oxide (NO) concentrations improving endurance performance. However, the effect of this supplement in team sport performance, especially in female athletes, has been barely studied. This study aimed to compare the acute effects of beetroot juice supplementation on neuromuscular performance and match-play demands in elite female field hockey players. METHODS: Eleven elite female hockey players (22.8 ± 5.1 years) belonging to a bronze team medal in Eurohockey Club Champions Cup participated in this study. Participants were randomly divided into two groups undergoing a test battery with beetroot juice (70 mL, 6.4 mmol NO3-) or placebo (70 mL, 0.04 mmol NO3-) in two different days with one week between protocols. The neuromuscular test battery consisted of a countermovement jump, isometric handgrip strength (i.e., dominant hand), 20 m-sprint and repeated sprint ability test (RSA). Afterward, a simulated hockey match play (2 × 12.5 min) was performed and recorded by Global Positioning System (GPS). RESULTS: No statistically significant improvements were observed in any physical parameters analysed comparing beetroot juice compared to placebo ingestion, countermovement jump (p = 0.776, ES = 0.16), isometric handgrip strength (p = 0.829; ES = - 0.08), 20 m sprint test (p = 0.227; ES = - 0.23), mean repeated sprint ability (p = 0.955, ES = 0.03) and in any physical match demands measured by GPS (p = 0.243-1.000; ES = 0.02-0.47). CONCLUSION: Acute beetroot juice supplementation did not produce any statistically significant improvement in neuromuscular performance or match-play demands in elite female field hockey players. TRIAL REGISTRATION: The study was registered in ClinicalTrials.gov with the following ID: NCT05209139. The study was retrospectively registered by 26 January 2022.

Association of the CKM rs8111989 Polymorphism with Injury Epidemiology in Football Players.

The influence of the rs8111989 polymorphism in the muscle-specific creatine kinase gene (CKM) on injury incidence is unknown. The aim was to investigate CKM polymorphism on injury incidence in high-performance football players. A cohort of 109 high-performance players was genotyped by using saliva samples. Injury incidence was similar in players with the GG, GA, and AA genotypes and did not modify incidence during training or match exposure (p=0.583 and p=0.737 respectively). GG players had a higher frequency of slight-severity injuries (60.0 vs. 10.2 vs. 24.2%, p<0.001), while GA players had a higher frequency of severe injuries (16.7 vs. 30.8 vs. 10.0%, p=0.021). GA players also had a higher frequency of muscle tears (34.8 vs. 59.0 vs. 20.0%, p<0.001). Muscle contracture was a more frequent injury in players with the GG genotype (40.0%, p<0.001). G allele carriers had lower frequencies of gradual-onset injuries (4.1 vs. 16.7%, p=0.035) and recurrent injuries (6.1 vs. 16.7%, p=0.003) than AA players. A allele carriers had higher frequency of severe injuries (10.0 vs. 21.9%, p=0.044) than GG players. Genotypes in the CKM rs8111989 polymorphism did not affect injury incidence in high-performance football players. Players with the GA genotype were more prone to severe injuries and muscle tears when compared to GG and AA players.

Genetic profile in genes associated with muscle injuries and injury etiology in professional soccer players.

Many causes define injuries in professional soccer players. In recent years, the study of genetics in association with injuries has been of great interest. The purpose of this study was to examine the relationship between muscle injury-related genes, injury risk and injury etiology in professional soccer players. In a cross-sectional cohort study, one hundred and twenty-two male professional football players were recruited. AMPD1 (rs17602729), ACE (rs4646994), ACTN3 (rs1815739), CKM (rs8111989) and MLCK (rs2849757 and rs2700352) polymorphisms were genotyped by using Single Nucleotide Primer Extension (SNPE). The combined influence of the six polymorphisms studied was calculated using a total genotype score (TGS). A genotype score (GS) of 2 was assigned to the "protective" genotype for injuries, a GS of 1 was assigned to the heterozygous genotype while a GS of 0 was assigned to the "worst" genotype. Injury characteristics and etiology during the 2021/2022 season were classified following a Consensus Statement for injuries recording. The distribution of allelic frequencies in the AMPD1 and MLCK c.37885C>A polymorphisms were different between non-injured and injured soccer players (p < 0.001 and p = 0.003, respectively). The mean total genotype score (TGS) in non-injured soccer players (57.18 ± 14.43 arbitrary units [a.u.]) was different from that of injured soccer players (51.71 ± 12.82 a.u., p = 0.034). There was a TGS cut-off point (45.83 a.u.) to discriminate non-injured from injured soccer players. Players with a TGS beyond this cut-off had an odds ratio of 1.91 (95%CI: 1.14-2.91; p = 0.022) to suffer an injury when compared with players with lower TGS. In conclusion, TGS analysis in muscle injury-related genes presented a relationship with professional soccer players at increased risk of injury. Future studies will help to develop this TGS as a potential tool to predict injury risk and perform prevention methodology in this cohort of football players.

Genetic profiles to identify talents in elite endurance athletes and professional football players.

The genetic profile that is needed to identify talents has been studied extensively in recent years. The main objective of this investigation was to approach, for the first time, the study of genetic variants in several polygenic profiles and their role in elite endurance and professional football performance by comparing the allelic and genotypic frequencies to the non-athlete population. In this study, genotypic and allelic frequencies were determined in 452 subjects: 292 professional athletes (160 elite endurance athletes and 132 professional football players) and 160 non-athlete subjects. Genotyping of polymorphisms in liver metabolisers (CYP2D6, GSTM1, GSTP and GSTT), iron metabolism and energy efficiency (HFE, AMPD1 and PGC1a), cardiorespiratory fitness (ACE, NOS3, ADRA2A, ADRB2 and BDKRB2) and muscle injuries (ACE, ACTN3, AMPD1, CKM and MLCK) was performed by Polymerase Chain Reaction-Single Nucleotide Primer Extension (PCR-SNPE). The combination of the polymorphisms for the "optimal" polygenic profile was quantified using the genotype score (GS) and total genotype score (TGS). Statistical differences were found in the genetic distributions between professional athletes and the non-athlete population in liver metabolism, iron metabolism and energy efficiency, and muscle injuries (p<0.001). The binary logistic regression model showed a favourable OR (odds ratio) of being a professional athlete against a non-athlete in liver metabolism (OR: 1.96; 95% CI: 1.28-3.01; p = 0.002), iron metabolism and energy efficiency (OR: 2.21; 95% CI: 1.42-3.43; p < 0.001), and muscle injuries (OR: 2.70; 95% CI: 1.75-4.16; p < 0.001) in the polymorphisms studied. Genetic distribution in professional athletes as regards endurance (professional cyclists and elite runners) and professional football players shows genetic selection in these sports disciplines.

Injury Incidence Increases after COVID-19 Infection: A Case Study with a Male Professional Football Team.

Background: The SARS-CoV-2 virus disease has caused numerous changes in sports routines in the last two years, showing the influence on an increase in sports injuries. The aim of this study was to prospectively analyze the incidence and characteristics of injuries in male professional football players diagnosed with COVID-19 when they return to play after recovering from this illness. Methods: Injury characteristics of professional male football players were recorded for the 2020−2021 season following the international consensus statement from the International Olympic Committee (IOC). SARS-CoV-2 infection in the football players was certified by PCR analysis. Injury epidemiology was compared in players infected by the SARS-CoV-2 virus before and after being diagnosed with COVID-19. Results: 14 players (53.8%) were diagnosed with COVID-19 during 2020−2021 season and 12 (46.2%) were not infected (controls). Only three (21.4%) had suffered an injury before being diagnosed with COVID-19. Eleven players (78.6%) had injuries after being diagnosed with COVID-19 (p < 0.001). Among the players diagnosed with COVID-19, injury incidence increased on their return to play after the infection (3.8 to 12.4 injuries/1000 h of exposure, p < 0.001). Additionally, injury incidence during training (10.6 vs. 5.1 injuries/1000 h of exposure, p < 0.001) and matches (56.3 vs. 17.6 injuries/1000 h of exposure, p < 0.001) was ~two-fold higher on return to play after COVID-19 compared to controls (33.4 vs. 17.6 injuries/1000 h of exposure, respectively, p < 0.001). Conclusions: Injury incidence in professional football players who had been infected by the SARS-CoV-2 virus significantly increased compared to the injury rates that these same players had prior to the illness. Additionally, the injury incidence was higher when compared to players who were not infected by the SARS-CoV-2 virus during the season, especially during matches.

Analysis of Sport Supplement Consumption by Competitive Swimmers According to Sex and Competitive Level.

Sports supplements (SS) are commonly used by athletes to improve their performance. SS use by competitive swimmers is reported to be prevalent but there is no evidence of such use by elite swimmers, either male or female. The objective of this research was to study the patterns of SS use by competitive swimmers based on sex and competitive levels (national and international); Methods: Using the categories of the Australian Institute of Sport (AIS), a total of 102 competitive swimmers (59 men and 43 women) completed a validated self-administered questionnaire on the use of SS; (3) Results: Overall, 86.9% of swimmers had consumed SSs with no differences observed between males and females (p = 0.247) or between competitive levels (p = 0.597). The SS that were most consumed by swimmers were caffeine (53.5%), sport drinks (52.5%), sport bars (51.5%), and vitamin C (43.4%). SSs categorized as medical supplements were consumed significantly more frequently by international swimmers (p = 0.012), with significant differences also found in the level-sex interaction (p = 0.049); (4) Conclusions: Compared to other sports disciplines, the prevalence of SS consumption is high in competitive swimmers regardless of performance level or gender. However, the consumption of medical supplements was greater in swimmers at a higher performance level.

Genetics and sports performance: the present and future in the identification of talent for sports based on DNA testing.

The impact of genetics on physiology and sports performance is one of the most debated research aspects in sports sciences. Nearly 200 genetic polymorphisms have been found to influence sports performance traits, and over 20 polymorphisms may condition the status of the elite athlete. However, with the current evidence, it is certainly too early a stage to determine how to use genotyping as a tool for predicting exercise/sports performance or improving current methods of training. Research on this topic presents methodological limitations such as the lack of measurement of valid exercise performance phenotypes that make the study results difficult to interpret. Additionally, many studies present an insufficient cohort of athletes, or their classification as elite is dubious, which may introduce expectancy effects. Finally, the assessment of a progressively higher number of polymorphisms in the studies and the introduction of new analysis tools, such as the total genotype score (TGS) and genome-wide association studies (GWAS), have produced a considerable advance in the power of the analyses and a change from the study of single variants to determine pathways and systems associated with performance. The purpose of the present study was to comprehensively review evidence on the impact of genetics on endurance- and power-based exercise performance to clearly determine the potential utility of genotyping for detecting sports talent, enhancing training, or preventing exercise-related injuries, and to present an overview of recent research that has attempted to correct the methodological issues found in previous investigations.

Effects of Six Weeks of Flywheel Single-Leg Romanian Deadlift Training on Speed, Jumping and Change of Direction Performance.

Several studies have confirmed the efficacy of flywheel training, mainly in the bilateral half-squat exercise. The aim of the present study was to analyze the effects of single-leg Romanian deadlift flywheel training on speed, jumping and change of direction performance. Seventeen young healthy males underwent two periods of 3-week training based on two weekly sessions of 3 sets × 7 repetitions or 4 sets × 7 repetitions of single-leg Romanian deadlifts (0.037 kg/m² moment inertia) with their dominant and non-dominant leg. After the first three weeks of the program, the CMJ, the 10 m, 30 m and total sprint times, as well as the COD-90 test, presented likely substantial beneficial effects and a small decrease in the relationship between the sprint and COD-90 test performance. After the second period of the three-week training, likely detrimental effects were observed in some of the change of direction conditions and an increase in the relationship between the sprint and the COD-180 performance. It could be hypothesized that most of the flywheel training effects reported in the traditional protocols lasting a minimum of 5-6 weeks would occur in the first weeks of training.

Effects of beetroot juice intake on repeated performance of competitive swimmers.

Background: Beetroot juice is a sport supplement with a high level of evidence on the physical performance enhancement. However, in swimming, there is no clear data about the effects of beetroot juice on performance. Objective: To investigate whether an acute intake of beetroot juice (BJ) improves the performance of competitive swimmers in a repeated maximum swimming effort. Method: Thirteen national-level swimmers (six females and seven males), participated in this randomized, double-blind crossover study. In two different trials, swimmers ingested a 70-mL placebo shot (.04 mmol NO3 -; PLA) or a 70-mL Beet-It shot (6.4 mmol of NO3 -beet juice [BJ]) 3 h before undergoing a 6 × 100-m front-crawl maximal effort test with 7 min rest between each 100 m. Results: Overall, 100-m times showed no difference between the BJ and PLA groups (p = .364), although a possibly shorter time was observed for BJ in the last repetition (p = .104; mean difference [MD] = -.99 s, mean-based inference [MBI] = 49/51/0). Participants in the BJ condition showed a possibly lower rate of perceived exertion in the first (p = .242, MD = -.85, MBI = 70/28/2) and second repetitions (p = .165, MD = 1.15, MBI = 83/16/1), whereas Total Quality Recovery scale scores were likely higher in the first (p = .110, MD = 1.15, MBI = 83/16/1) and third (p = .082, MD = -.77, MBI = 70/29/1) repetitions compared with those in the PLA group. Blood lactate concentration [La+] levels showed no differences between groups in any of the repetitions (p > .05, unclear), and we observed an increase in 100-m times for both BJ and PLA (BJ: p = .014, MD = -1.51 s; PLA: p = .029, MD = -1.57 s) after the fifth repetition. Conclusion: No clear differences in performance were observed in a 6 × 100-m repeated sprint test by competitive swimmers when supplementing (or not) with BJ. However, there was a trend toward a better recovery between efforts and a better tolerance of fatigue when swimmers ingested BJ.

External and internal loads during the competitive season in professional female soccer players according to their playing position: differences between training and competition.

The aim of this study was to compare external (EL) and internal loads (IL) during training sessions compared to official matches between elite female soccer players according to their playing position.Training and match data were obtained during the 2017/18 season from eighteen players (age: 26.5±5.7 years; height: 164.4±5.3 cm; body mass: 58.56±5.58 kg) from a first Division Spanish team. The EL (total distance covered; high-speed running distance; number of accelerations and decelerations) was assessed with a Global Positioning System (GPS) and triaxial accelerometer. The IL was assessed with ratings of perceived exertion (RPE; and session-RPE).The EL and the IL from official matches were higher compared to training sessions (p<0.05; effect size [ES]:0.6-5.4). In matches, the EL was greater in Attackers (AT) and Central Midfielders (CM) versus Central Backs (p<0.05; ES:0.21-1.74). During training sessions, the EL was similar between playing positions (p>0.05; ES:0.03-0.87). The EL and the IL are greater in matches compared to training sessions, with greater match-related EL in AT and CM players. Current results may help practitioners to better understand and modulate training session's loads according to playing position, potentially contributing to their performance readiness and injury risk reduction.

Relationships between Strength and Step Frequency with Fatigue Index in Repeated Sprint Ability.

Force-velocity profile (FVP) and repeated-sprint ability (RSA) tests are indicators of physical capacities in most team sport players. The purpose of this study was to examine the stride kinematics during a repeated-sprint ability (RSA) test and to analyze the relationship between Bosco's force-velocity profile (FVP) and RSA performance in elite female field hockey players. Thirteen elite-female players performed both RSA (six 30 m maximal sprints) and jumping (CMJ weighted and body weight) tests. Sprinting time fatigue indexes during a 30 m RSA test were correlated with step frequency fatigue indexes (r > 0.7; p < 0.01). CMJ50 showed a large relationship with sprint time fatigue indexes. FV50 showed a very large relationship with sprint time fatigue indexes (r > 0.7; p < 0.01), and a large relationship with the step frequency fatigue indexes (r > 0.5; p < 0.05). This study highlighted two possible ways to improve fatigue indexes in RSA, with the aim of maximizing the distances covered at high-intensities during the matches: (a) strength training and (b) focusing on step frequency during speed training.

Effects of Caffeine Ingestion on Physical Performance in Elite Women Handball Players: A Randomized, Controlled Study.

PURPOSE: To investigate the effects of acute caffeine (CAFF) intake on physical performance in elite women handball players. METHODS: A total of 15 elite women handball players participated in a randomized, double-blind study. In 2 different trials, participants ingested either a placebo (cellulose) or 3 mg of CAFF per kilogram of body mass (mg/kg bm) before undergoing a battery of neuromuscular tests consisting of handball throws, an isometric handgrip strength test, a countermovement jump, a 30-m sprint test (SV) and a modified version of the agility T test. Then, participants performed a simulated handball game (2 × 20 min), and movement patterns were recorded with a local positioning system. RESULTS: Compared with the placebo, CAFF increased ball velocity in all ball throws (P = .021-.044; effect size [ES] = 0.39-0.49), strength in isometric handgrip strength test (350.8 [41.2] vs 361.6 [46.1] N, P = .034; ES = 0.35), and countermovement-jump height (28.5 [5.5] vs 29.8 [5.5] cm; P = .006; ES = 0.22). In addition, CAFF decreased running time in the SV (4.9 [0.2] vs 4.8 [0.3] s; P = .042; ES = -0.34). In the simulated game, CAFF increased the frequency of accelerations (18.1 [1.2] vs 18.8 [1.0] number/min; P = .044; ES = 0.54), decelerations (18.0 [1.2] vs 18.7 [1.0] number/min; P = .032; ES = 0.56), and body impacts (20 [8] vs 22 [10] impacts/min; P = .032; ES = 0.30). However, postexercise surveys about self-reported feelings of performance indicate that players did not feel increased performance with CAFF. CONCLUSION: Preexercise ingestion of 3 mg/kg bm of CAFF improved ball-throwing velocity, jump, and sprint performance and the frequency of in-game accelerations and decelerations in elite women handball players.

Effects of 7-Week Hip Thrust Versus Back Squat Resistance Training on Performance in Adolescent Female Soccer Players.

Hip thrust (HT) is a loaded bridging exercise that requires more hip extension than a back squat (SQ) does, while in a back squat, triple flex extension occurs. Due to the specificity of each exercise, it is claimed that HT gains can be better transferred to actions where hip extension occurs. In addition, strength improvements during squatting can be transferred in a greater way to vertical plane movement, such as vertical jumping. However, its effects on the performance of female soccer players are unclear. For this reason, the purpose of this study was to analyze a 7-week training program on performance variables using either HT or SQ exercises in female adolescent soccer players without lifting experience (N = 24, age = 16.82 ± 1.56 years, height = 1.64 ± 0.55 cm, body mass = 58.35 ± 6.28 kg). Players were randomized into three groups: A back squat group (SQG; N = 8), hip thrust group (HTG; N = 8), and control group (CG; N = 8). Participants in the HTG and SQG joined a progressive resistance training program twice per week for 7 weeks with either HT or SQ exercises. A countermovement jump, 10-20 m sprint, T-test, and barbell velocity during HTs and SQs (with the load that represents ~60 and ~80% RM) were measured before and after the intervention. The HTG showed greater improvements in the 10-m sprint (d = 0.7), 20-m sprint (d = 0.46), T-test (d = 0.36), and barbell velocity at 80% repetition maximal (RM) (d = 0.53) and 60% RM (d = 1.02) during hip thrusts, while the SQG showed higher barbell velocity at 80% RM (d = -0.7) during back squats. These results may be useful for strength and conditioning coaches working with adolescent female soccer athletes, since both strengthening exercises improved performance in different ways due to the nature of the exercise.

Effects of Vibration and Non-Vibration Foam Rolling on Recovery after Exercise with Induced Muscle Damage.

We aimed to compare the effects between non-vibration foam rolling (NVFR) and vibration foam rolling (VFR) on visual analogic scale (VAS), pressure pain threshold (PPT), oxygen saturation (SmO2), countermovement jump (CMJ) and hip and knee range of movement (ROM) after eliciting muscle damage through eccentric acute exercise using an inertial flywheel. Thirty-eight healthy volunteers (32 men, 6 women; aged 22.2±3.2 years) were randomly assigned in a counter-balanced fashion to either a VFR or NVFR protocol group. All participants performed a 10x10 (sets x repetitions) eccentric squat protocol to induce muscle damage. The protocols were administered 48-h post-exercise, measuring VAS, PPT, SmO2, CMJ and ROM, before and immediately post-treatment. The treatment technique was repeated on both legs for 1 minute for a total of five sets, with a 30-s rest between sets. The VFR group showed substantially greater improvements (likely to very likely) in the passive VAS (VFR -30.2%, 90% CI -66.2 to -12.8) with chances for lower, similar or greater VAS compared with the NVFR group of 82%, 14% and 4%, respectively and passive extension hip joint ROM (VFR 9.3%, 90% CI 0.2-19.2) with chances for lower, similar or greater ROM compared with the NVFR group of 78%, 21% and 1%, respectively. For intragroup changes, we observed substantial improvements in VAS (p=.05), lateral vastus, rectus femoris and medial vastus PPT. The results suggest that the VFR group achieved greater short-term benefits in pain perception and passive extension hip joint ROM. Both protocols were effective in improving PPT, SmO2, CMJ and knee joint ROM. The enhanced improvement in VAS and hip ROM measures could have significant implications for VFR treatment.

The Use of Generic and Individual Speed Thresholds for Assessing the Competitive Demands of Field Hockey.

The current study compared the running demands of professional field hockey players using individualized speed zones and generic default settings of the GPS manufacturer. In addition, the differences in slow, moderate and fast players were studied. Sixteen male players from the same club participated in the study (age: 25.5 ± 2.9 years; body mass: 74.6 ± 5.5 kg; stature 1.77 ± 0.05 m). The peak speed of each participant was established at the end of the data collection period by analyzing all training and playing data throughout the season. Using players peak speed achieved for each participant during the season, individualized speed zones were retrospectively applied to all match-play data. Peak speed was used to categorize players into three groups, slow (5 players: 29.2-30.2 km·h-1), moderate (6 players: 30.7-31.5 km·h-1) and fast (5 players: 32.2-33.7 km·h-1). Significant differences were observed between generic and individual thresholds for the distance covered in moderate, high, and very high-speed running in all positions (p = 0.01). Our findings show that the distances covered at high-speeds in midfielders and forwards were overestimated, while the very high-speed running and sprinting in backs were underestimated. Generic speed thresholds should be used if comparisons between positions is of importance. However, based on the different capacities of field hockey players, individual speed thresholds may be more suitable when addressing the relative stress on individual athletes.

Positional Comparisons in the Impact of Fatigue on Movement Patterns in Hockey.

PURPOSE: To examine the influence of the match period on the movement patterns of hockey players according to their playing positions under the introduction of quarters (QTRs). METHODS: Sixteen subelite-level Spanish National League male hockey players participated in the study (age: 25.5 [2.9] y; body mass: 74.6 [5.5] kg). Global positioning system devices were used to monitor players' running performance during 17 competitive matches (113 match-play profiles). Only players who played for at least 85% of the game were analyzed. Players were placed into 3 position categories: backs, midfielders, and forwards. RESULTS: Moderate to large differences in relative total distance were found between midfielders and both backs and forwards in all QTRs (effect size [ES]: 0.4-1.2). ES for total distance was moderate for midfielders when compared with backs during the first QTR (moderate ES: 0.7). Midfielders and forwards covered more distance (m and m·min-1) in high-velocity zones than backs (ES: 0.6). Acceleration activities (n·min-1) at moderate and high intensities decreased in all groups across QTRs with moderate to very large ES (ES: 0.4-1.4). Relative sprinting distance decreased in backs (ES: 0.8). Backs had fewer repeated-sprint bouts (n and n·min-1) as the game progressed (ES: 1.0). CONCLUSIONS: During competitive match play, a degree of positional variation can be observed across QTRs. The relative distance and the number of accelerations and decelerations at moderate and high intensity decreased across QTRs. No between-QTRs differences in high-speed activity were reported.

Cardiovascular Fitness and Energy Expenditure Response during a Combined Aerobic and Circuit Weight Training Protocol.

OBJECTIVES: The present study describes the oxygen uptake and total energy expenditure (including both aerobic and anaerobic contribution) response during three different circuit weight training (CWT) protocols of equivalent duration composed of free weight exercises, machine exercises, and a combination of free weight exercises intercalating aerobic exercise. DESIGN: Controlled, randomized crossover designs. METHODS: Subjects completed in a randomized order three circuit weight training protocols of the same duration (3 sets of 8 exercises, 45min 15s) and intensity (70% of 15 repetitions maximum). The circuit protocols were composed of free weight exercises, machine exercises, or a combination of free weight exercises with aerobic exercise. Oxygen consumption and lactate concentration were measured throughout the circuit to estimate aerobic and anaerobic energy expenditure respectively. RESULTS: Energy expenditure is higher in the combined exercise protocol (29.9±3.6 ml/kg/min), compared with Freeweight (24.2±2.8ml/kg/min) and Machine (20.4±2.9ml/kg/min). The combined exercise protocol produced the highest total energy expenditure but the lowest lactate concentration and perceived exertion. The anaerobic contribution to total energy expenditure was higher in the machine and free weight protocols compared with the combined exercise protocol (6.2%, 4.6% and 2.3% respectively). CONCLUSIONS: In the proposed protocols, the combined exercise protocol results in the highest oxygen consumption. Total energy expenditure is related to the type of exercise included in the circuit. Anaerobic contributions to total energy expenditure during circuit weight training may be modest, but lack of their estimation may underestimate total energy expenditure. TRIAL REGISTRATION: ClinicalTrials.gov NCT01116856.

Can the exercise mode determine lipid profile improvements in obese patients?

INTRODUCTION: Unfavorable lipid profile is associated with developed cardiovascular diseases. It is necessary to know the beneficial effects of different mode exercises to improve lipid profile. OBJECTIVE: To investigate, in obese men and women, the effect on lipid profile of hypocaloric diet combined with structured exercise programs or recommendations of physical activity. METHODS: Ninety six obese subjects (59 women and 61 men; 18 - 50 years; BMI >30 and < 34.9 kg/m(2)) were randomised into four supervised treatment groups: strength training (S; n = 24), endurance training (E; n = 26), combined S + E (SE; n = 24), and and received recommendations of physical activity (PA; n = 22). Energy intake, body composition, training variables (VO(2peak), strength index, dynamometric strength index) and blood lipid profile were recorded at baseline and after 24 weeks of treatment. RESULTS: Blood lipid profile improved in all groups. No statistically significant differences in baseline and posttraining values were observed between groups. HDLCholesterol showed no changes. A decrease in LDLCholesterol values was observed in all groups after the intervention (S: 11.2%, E: 10.8%, SE: 7.9%, PA: 10.8%; p < 0.01). S, E and PA subjects showed decrease in triglycerides (S: 14.9%, E: 15.8%, PA: 15.7%; p < 0.01). Total cholesterol decreased in all groups (S: 8.4%, p < 0.01; E: 8.8%, p < 0.01; SE: 4.9%, p < 0.01; PA: 8.3%, p < 0.05). CONCLUSION: All protocols proposed in our study improved blood lipid profile in obese people. There were no significant differences about the effect on the lipid profile between the implementation of a structured training protocol with physical activity professional supervision and follow recommendations of physical activity.

Introducción y objetivo: El perfil lipídico desfavorable se asocia con el desarrollo de enfermedades cardiovasculares. Para reducir este factor es necesario estudiar el impacto que los diferentes modos de ejercicio con dieta tienen sobre el perfil lipídico. Por ello, el objetivo de este trabajo fue investigar, en hombres y mujeres obesos, el efecto sobre el perfil lipídico de la dieta hipocalórica combinada con programas de ejercicios estructurados o recomendaciones de actividad física. Métodos: Noventa y seis participantes con obesidad (edad entre 18-50; IMC > 30 and < 34.9 kg/m2) fueron repartidos en 4 grupos: fuerza (S; n = 24), aeróbico (E; n = 26), combinado de fuerza y aeróbico (SE; n = 24), los cuales entrenaron 3 veces/semana durante 22 semanas, y el grupo de recomendaciones de actividad física (PA; n = 22). A todos se les asigno una dieta equilibrada con un 35% de restricción. Antes y después de la intervención todos los grupos fueron evaluados de los cambios en el perfil lipídico, la composición corporal y la ingesta diaria. Resultados: El perfil lipídico mejoró en todos los grupos. No se observaron diferencias significativas en los valores basales y tras la intervención entre los grupos. El HDL no mostró cambios. Para los valores de LDL se observó una disminución significativa en todos los grupos (S: 11,2%, E: 10,8%, SE: 7,9%, PA: 10,8%). Los sujetos S, E y PA mostraron una disminución en los triglicéridos (S: 14,9%, E: 15,8%, PA: 15,7%; p < 0,01). El colesterol total disminuyó significativamente en todos los grupos (S: 8,4%, E: 8,8%, SE: 4,9%, PA: 8,3%). Conclusiones: Todos los protocolos propuestos en nuestro estudio mejoraron el perfil lipídico en personas obesas. No hubo diferencias significativas en cuanto al efecto sobre el perfil lipídico entre la aplicación de un protocolo de entrenamiento estructurado que seguir las recomendaciones de actividad física.