A new device to increase the medial-to-lateral hamstring and quadriceps co-contraction ratios in female athletes
Background : Because athletes rely on sports physicians as a source of information, physicians must be included in research relating to doping prevention. According to several studies, the level of knowledge of sports physicians with regard to doping prevention seems to be inadequate. It is crucial for them to have a comprehensive understanding of doping regulations, substances and the side effects, as well as the procedure for issuing Therapeutic Use Exemptions (TUE). Research questions : (1) to evaluate the knowledge of Austrian sports physicians regarding doping substances, doping methods and side effects and (2) to provide ideas on efficient strategies to educate this target group. Methods : An online questionnaire was distributed to all registered Austrian physicians who hold a Supplementary Diploma in Sports Medicine (n = 1,543). The questionnaire was administered over four months and structured into eight areas of interest. Chi-Square tests, as well as descriptive statistics, were used to analyse the data. Results : A total of 152 physicians returned the questionnaire (response rate of 9.8%). Some 53.7% subjectively believed that they were poorly informed about the topic, and 43% reported that they knew of the World Anti-Doping Agency (WADA) 2011 Prohibited List. Knowledge deficits regarding substances (especially insulin, recombinant human erythropoietin, stimulants) and strong uncertainties with regard to prohibited doping methods and the side effects of specific substances were reported. This low level of knowledge stood in contrast to the high interest in the topic that the physicians self-reported. In general, physicians had a very positive anti-doping attitude. Conclusion : Results of this study are comparable with previous studies conducted in Germany and France. Despite the low response rate, this study demonstrated high interest from sports physicians regarding doping, and showed some of the deficits in their knowledge of doping. Integrating anti-doping related information within educational material may assist increasing the knowledge of sports physicians and gain their support for wider anti-doping strategies.
Tendinopathies are common clinical pathologies leading to local disability and impaired athlete's performance. A diagnosis of tendinopathy is based on local symptoms under physical load and pain on tendon palpation. To verify structural alterations of the tendon, ultrasound and/or MRI examinations are useful. Basically, any tendon can be affected. However, highest rates of tendinopathy are seen in the Achilles and patella tendons of athletes. Sport-specific accumulation of complaints is usually explained by regionally higher tendon loading leading to intratendinous micro ruptures, with loss of hierarchical collagen fibre organisation.Non-surgical treatment is recommended as the initial strategy in tendinopathies at all locations. In general, the treatment approach is multifactorial and consists of both exercise and physical therapy. Different methods aim to stimulate collagen synthesis, reduce tissue adhesions and free nerve endings, as well as optimising the stress onto the tendon by improved load management. As a result of recent evidence, it can be stated that eccentric training regimens lead to favourable results with less pain and improvement in function within 12 weeks of application. Shock wave and laser therapy show promising results on pain reduction at some locations. Systemic or local usage of medication has to be considered as an additional, practically relevant therapeutic tool without significant evidence for use in athletes. Location-wise modification of treatment strategy has to be undertaken.
To study the exercise-induced arterial hypoxaemia (EIAH) kinetics in a world class Ironman triathlete at ventilatory threshold (THvent), the authors simulated the cycle-run succession (CR, 20 min + 20 min) and a 20-min isolated run (R). Although 'moderate EIAH' was noted during CR, the SpO2 kinetics of the isolated R reflected 'severe EIAH' from minutes 7 to 15 with a nadir of 85 % SpO2 that stabilised at 90 % SpO2 from minute 15 on. The physiological processes involved in these responses are discussed. These data indicate a systematic 'moderate EIAH' in a world class Ironman champion during CR and R at THvent and a temporary 'severe EIAH' during R, which was attenuated when running was successive to cycling. The physiological significance of this phenomenon remains unclear, however, and further experiments are needed.
Background : Low saddle height has been empirically linked to increased compressive force at the patellofemoral joint and to the development of overuse knee pain. Research question : How changes in saddle height would affect patellofemoral and tibiofemoral forces of cyclists with and without knee pain. Type of study : Cross-sectional. Methods : Sixteen cyclists without knee pain and eight cyclists with knee pain performed four 2-minute submaximal cycling trials using their preferred saddle height, two saddle heights (high and low) eliciting ±10° change in knee flexion angle, in relation to their preferred saddle height, and a saddle height eliciting 25° knee flexion at the 6 o'clock crank position. Workload (3.04 ± 0.78 W/kg) was consistent and pedalling cadence was visually controlled at 90 rpm for every trial. Right pedal forces and joint kinematics recorded during all trials enabled calculation of patellofemoral and tibiofemoral forces using a musculoskeletal model. Results : Changes in saddle height did not substantially affect patellofemoral and tibiofemoral forces when comparing cyclists with and without knee pain. Compared to the low saddle height there were larger anterior tibiofemoral forces at optimal (35% without pain, 51% pain) and high saddle heights (76% without pain, 92% pain). Conclusions : Bicycle saddle height can probably be set within a large range of knee motion (i.e., ~44-65° determined during dynamic cycling at the 3 o;clock position) to minimise possible detrimental effects of large patellofemoral and tibiofemoral forces.
Background : The number of runners has been increasing as well as the number of injuries related to this sport. Knowing the foot strike patterns of the runners has become necessary since there is a possible relationship between the landing pattern of the foot against the ground during running and the increased incidence of musculoskeletal injuries in runners.Research question : The objective of this study was to determine the distribution of the foot strike patterns in recreational runners during typical training running pace.Type of study : Cross-sectional study.Methods : This is a cross-sectional study conducted with recreational runners who practice with running coach. A high-speed camera (image acquisition frequency of 250 Hz) was used to analyse the foot strike pattern and photocells were used to register the runners' speed. The foot strike patterns were classified into three categories: rearfoot, midfoot and forefoot. The description of the foot strike pattern and the characteristics of participants were done through descriptive statistics. Intra-class and inter-class confiability was evaluated by agreement percentage.Results : Fifty-three runners, with an average speed of 12.6 km/h, were evaluated, and 98.1% of the runners showed a rearfoot strike pattern. Only one runner touched the ground with the midfoot first, and none were forefoot strikers. The evaluation method for determining foot strike pattern showed an agreement percentage of 96.2% and 100% intra-class and inter-class confiability, respectively.Conclusion : The results of the study showed that the adult recreational runners who train with a one running coach, almost exclusively demonstrate a rearfoot strike pattern during running.
Background : Recently, there has been increasing interest in gathering epidemiological data through standardised assessment for the health of athletes. Research question : This study prospectively examined the epidemiologic profile of acute and chronic sports injuries incurred by the national athletes of the Korean Olympic Committee (KOC) during the 16th Summer Asian Games. Type of study : Prospective epidemiologic surveillance. Methods : All medical personnel of the KOC were instructed to complete and return a daily injury report form, and all physicians were asked to fill in the clinical diagnoses after a thorough examination. The frequency, characteristics, and clinical diagnoses of all sports injuries were examined, and the incidence and injury risk across different sports were compared. Chronic conditions prevalent in elite athletes were also assessed. Results : The number of sports injuries that were reported was 725 (430 athletes); of these 725, 288 were acute injuries (209 athletes), including 68 recurrent injuries (58 athletes), and 437 were chronic injuries (305 athletes). The largest number of acute and recurrent injuries was reported in athletics (37 acute injuries and 16 recurrent injuries). Acute injuries were incurred in competition (n=126; 43.8%) and during practice (n=162; 56.3%), and recurrent injuries in competition (n=18; 26.5%) and during practice (n=50; 73.5%). The incidence rate (IR) of acute injuries was 37.9 (95% Confidence Interval [CI]; 33.5-42.3) injuries/1,000 athlete-exposures (AEs), and the IR of recurrent injuries was 9.0 (95% CI; 6.8-11.1) injuries/1,000 AEs. Athletics also showed the highest IRs for both acute and recurrent injuries (245.0 injuries/1,000 AEs, 95% CI; 166.1-324.0, and 106.0 injuries/1,000 AEs, 95% CI; 54.0-157.9, respectively). 26.4% (95% CI; 23%-30%) of the registered athletes sustained acute injuries, and 7.3% (95% CI; 6%-9%) of them incurred recurrent injuries. Basketball (67%, 95% CI; 48%-86%) and field hockey (66%, 95% CI; 49%-82%) showed high IPs for acute injuries and the IP for recurrent injuries was high in athletics (27%, 95% CI; 14%-40%). Lateral ankle ligament sprain was the most frequent acute injury (n=28; 9.7%, 95% CI; 27-29), whereas calf muscle cramps was the most frequent recurrent injury (n=11; 16.2%, 95% CI; 10.3-11.7). The prevalence of chronic injuries was highest in wrestling (n=31; 7.1%, 95% CI; 26.7-35.3), and the most prevalent chronic injury was chronic ankle instability and lumbar myofascial pain (n=51; 11.7%, 95% CI; 49.6-52.4, respectively). Conclusions : The statistics of this epidemiologic study indicated the wide range of the incidence, prevalence and characteristics of injuries in different sports during the 16th Summer Asian Games, and the data from the sports might be compared using the statistical measures of the injury surveillance in this study. Therefore injury prevention programmes should be tailored to the injury profile of the respective sport for the major international multi-sport events.
Background : Non-medical anabolic steroid (AS) use in non-professional athletes is an increasingly recognized public health problem in Europe and the United States but poorly studied in the Middle East. Research question : The aim of this study is to assess the prevalence and determinants of anabolic steroid use amongst adult fitness centre attendees in the Greater Beirut area, Lebanon. Type of study : A cross-sectional study design was adopted. Methods :Subjects: The targeted population included all gym attendees in Greater Beirut aged 18 or above. Professional or career athletes competing in organized sports were excluded. Questionnaire: A questionnaire was used to survey participants on demographic information, history of anabolic steroid usage and possible determinants of use. Sampling: A list of 53 fitness centres in the Greater Beirut area was identified. Thirty-three gyms agreed to permit access to their centres. Trained research assistants distributed the questionnaire to all gym attendees on arrival, during equally selected day and evening intervals. A total of 523 gym attendees completed the survey. Results : The prevalence of any history of anabolic steroid use was 10.7%. The majority of users (78.2%) were aware of the adverse health effects. The main reason for usage reported was body image enhancement (82.0%). Demographic factors associated with anabolic steroid use were: male gender, separated/divorced status and full-time employment. Conclusion : Non-medical anabolic steroid use is a public health concern in Lebanon that should be addressed by monitoring AS use in health clubs and with educational programs aimed at high-risk groups, health practitioners and health clubs that not only focus on risk awareness but also on media literacy and body image attitudes.
Background: Serum magnesium (SMg) has been used as part of the pre-participation physical examination of athletes but the clinical usefulness of this biochemical index is unknown. Research question: Do footballers have lower SMg during active rest than footballers involved in full training? Type of study: Prospective descriptive study. Aim: To compare the SMg of 3 groups: 23 professional footballers after active rest for a mean of seven days (RT), 23 professional footballers in active training (AT), and 63 less physically active males (CG). Methods: After an overnight fast, blood was drawn by a standardised protocol from players belonging to the RT, AT and CG groups respectively. Each group was analysed on a separate occasion. Results: The median SMg (IQR) in the RT, AT and CG groups were 1.3 (1.2, 1.4); 2.0 (1.9, 2.1) and 1.9 (1.8, 2.1) mg/dl respectively (p<0.0005 for the difference between RT and both AT and CG groups). Conclusion: SMg in the RT group was significantly lower than that found in the CG and AT groups. The SMg of the RT group lay at the low end of the normal range for magnesium, and this may represent the chronic effect of football on this biochemical index. SMg may have a role as a marker of reduced training load in professional footballers. Physicians should enquire about the training status of these players before interpreting SMg levels.
Background : The energy cost of running per unit mass and distance (Cr) is reported to increase or to remain constant after a fatigue test in young healthy adults. No studies had been performed on master athletes on this topic. Research question : Does the energy cost of running increase after a half marathon in a group of master athletes? Type of study : Pre-Post single group design. Methods : Ten healthy master athletes took part in the experiment. The experimental protocol involved an incremental test to exhaustion, a half marathon simulation, and two sessions of energy cost assessments before and after the race simulation. Results : Neither comparing fatigue to no-fatigue conditions (p>0.05) nor as a function of the running speed (p>0.05) could show a change in the group mean energy cost. Conclusions : The energy cost of running is not affected by a half marathon race within a group of master athletes.
Background: Bilateral strength imbalance in the lower extremities has been studied in several sports as well as cycling and running. However, there has been little investigation of the differences in muscle strength and leg asymmetries in vertical jump between elite runners and cyclists. Research question: The primary purpose of this investigation was to determine the differences in vertical jump capacity between elite athletes (runners and cyclists). A secondary purpose was to describe single leg vertical jump capacity and leg asymmetries in elite athletes. Type of study: The evaluation sessions consisted of a different vertical jump tests. Methods: 27 elite male endurance athletes (endurance runners and road cyclists) performed a countermovement jump (CMJ), single leg CMJ, arm swing CMJ and a 10 s repeat jump (RJ) test. Results: The runners had a significantly greater (p < 0.01) jump performance in the double leg CMJ (19%), arm swing CMJ (27%) and RJ (16%) compared with cyclists. Similarly, single leg vertical jump performance was significantly better in runners compared with cyclists both with reference to the right leg CMJ (13.4%, p < 0.05), left leg CMJ (15.5%, p < 0.05), dominant leg CMJ (12.6%, p < 0.05) and non-dominant leg CMJ (16.4%, p < 0.01). Significant differences between dominant leg CMJ and non-dominant leg CMJ performance in jump height (leg asymmetry 5.5%) and power production (leg asymmetry 6.5%) were found in the runners' group. In the cyclists' group, significant differences were also found between dominant leg CMJ and non-dominant leg CMJ jump height (leg asymmetry 9.7%) and power production (leg asymmetry 14.6%). Conclusions: The present study demonstrated a markedly higher single and double leg vertical jump capacity in elite endurance runners compared with professional road cyclists.
Background: Baseball pitching involves coordinated movements between the upper extremity, trunk, and lower extremity. Among pitchers, hamstring injuries are the second most common lower extremity injury. Research question: Investigate the 10-year incidence and demography of hamstring injuries in Major League Baseball pitchers. Type of study: Descriptive study. Methods: The Major League Baseball Disabled list from 2001 to 2010 identified 61 pitchers with hamstring injuries. Age, body mass index, throwing hand dominance, and days on the Disabled list were analysed. Results: The annual incidence of hamstring injuries increased over time. Mean age at injury was 30.6 ± 5.1 years, mean height 188.7 ± 5.8 cm, mean weight 99.8 ± 12.1 kg, and mean BMI 28.0 ± 2.8 kg/m2. Mean length of stay on the disabled list was 27.7 ± 20.0 days. There was a correlation between age and BMI (p < 0.010). There was no correlation between days on the Disabled list and age (p = 0.275) or BMI (p = 0.908). There was no difference in age (p = 0.381), BMI (p = 0.736), or days on the Disabled list (p = 0.530) between pitchers with injured hamstrings ipsilateral versus contralateral to their throwing arm. Conclusions: The incidence of hamstring injuries in Major League Baseball pitchers increased over time. Number of disabled days averaged 4 weeks, but was variable. Injuries contralateral to the throwing arm were more common but not more debilitating. These findings can be useful for preventive strengthening programmes and rehabilitation techniques in pitchers.
Background : The continuous growth of the elderly population is forcing developed nations to invest effort in the search for interventions and physical exercise programmes, with the aim of increasing the well-being and quality of life of this adult population. Research question : The purpose of this study was to determine the efficacy of physical exercise in the elderly using different intervention methodologies (recommendation, home prescription, and monitoring). Type of study : Experimental study. Methods : One hundred subjects who were 55-70 years of age were recruited and randomized into four groups of 25: CON=control, REC=recommendation, PRE=prescription, and MON=monitoring. The participants followed a structured physical exercise programme for 12 weeks. Each participant's physical condition was evaluated before and after the intervention using a battery of tests that included the scoring of strength, flexibility, balance, and aerobic resistance. Results : The MON group showed significant improvements in all variables (p<0.001). However, the PRE group did not exhibit increased performance in resistance or balance. The MON and PRE groups were significantly different in all variables studied (p<0.01) except for equilibrium with eyes open. Nonetheless, significant improvements in the strength variables were observed in the PRE group compared to the CON and REC groups (p<0.01 and p<0.05). The improvements in resistance, flexibility, and balance were not significant. Conclusions : A WREP programme is useful for improving physical conditions in both a prescribed home form and a monitored form. However, a simple recommendation does not seem to be sufficient. Nevertheless, the exercise with instructor has greater impact on the physical health of the elderly.
Background: Allergy and asthma represent important problems for athletes. Also, exercise is known to induce oxidative stress and increase in reactive oxygen species during exercise might overwhelm endogenous antioxidant defence. Type of study: Original research concerned the oxidative stress in athletes with IgE-dependent allergic response. Research question: The aim of the present work was to assess oxidative stress biomarkers in elite athletes with known allergy and non-allergic controls. Methods: Based on serum IgE concentration (cut-off 100 IU/L) and findings at physical examination, 66 elite athletes were divided into two groups: with some kind of IgE-dependent allergic response (n=19) and healthy controls (n=47). The following parameters were measured: White blood cell count (WBC), Immunoglobulin E (IgE), high sensitive C reactive protein (hs-CRP), Interleukin-6 (IL-6), oxidative stress parameters (reactive oxygen metabolites - ROMs, advanced oxidation protein products - AOPP and lipid hydroperoxides - LOOH) and biological antioxidative potential - BAP. Results: Multivariate analysis of covariance revealed that IgE-dependent allergic response contributed 16.9 % to variability of oxidative status and hs-CRP and WBC to be significant covariates. Reactive oxygen metabolites (327 ± 81 vs. 294 ± 53; P=0.047) were significantly higher in athletes with IgE-dependent allergic response and biological antioxidative potential (2314 ± 344 vs. 2484 ± 226; P=0.031) was significantly lower in this group. Conclusions: Increased reactive oxygen metabolites and reduced antioxidant capacity in athletes with IgE-mediated allergy lead us to suppose that free radical generation could be mediated at least in part via type I hypersensitivity response.
The aim of this study was to examine the relationships between short sprint time (30 metres) and several kinetic variables of the countermovement jump (CMJ) in a sample of trained athletes. A group of 12 trained athletes volunteered to participate in the study (mean ± SD: age 22.2 ± 1.2 years, body mass 67.5 ± 5.5 kg, body height 1.75 ± 0.02 m). Following a standard warm-up, participants performed three maximal CMJ trials on a Smith machine and three maximum effort sprints of 30 metres. The major findings of this study were the significant associations between 30 metre sprint time and the concentric phase of CMJ for both force and power parameters. In addition, non-significant predictive values were observed between sprint performance time and jump impulse values. The results are of practical interest for optimising training and assessment methods in sprint performance.
Background: The aims of this study were firstly, to describe the variation in total testosterone (TT) and cortisol (C) through the course of a complete season in elite male basketball players and secondly, to analyse their relation to training frequency and playing time. Type of study: Observational descriptive with repeated measures and non-randomised sampling. Methods: Eight professional male basketball players (27.8 ± 4.9 years; 97.0 ± 9.5 kg; 197.2 ± 7.3 cm; 24.7 ± 1 BMI) participated in the study. Firstly, blood samples were collected just after the off season period. These values were considered as baseline. During the competitive season, samples were taken periodically every four to six weeks, in a resting state, always after 24-36 hours break following the last game played. Eight samples were collected from August to April. Results: TT concentration showed significant variations amongst blood samples: April vs. September (-4.4 nMol/l, p=0.010, d=1.1), April vs. October (-4.9 nMol/l, p=0.004, d=1.27) and April vs. February (-6.8 nMol/l, p=0.013, d=2.08). TT did not correlate with playing time. C concentration and the TT/C ratio did not show any significant variation throughout the season and also did not correlate with playing time. Conclusions: The effect of a basketball season can be reflected in TT. It is interesting to differentiate between the three phases of the season: 1) pre-season, 2) first two-thirds of the regular season and 3) last third of the regular season, where fatigue accumulation at a metabolic level occurs. TT could be an indicator of players' state, which would justify, in conjunction with other indicators, the necessity to optimise players' workload and to individually prevent overtraining.
Background : Few studies have investigated resistance training and its physiological and functional effects in the hypertensive elderly. Research question : The study aimed to analyse the effect of resistance training on resting blood pressure, body composition, muscular strength, functional capacity and blood variables in hypertensive elderly. Type of study : Randomised controlled study. Methods : Participants were 17 hypertensive elderly women divided into a training group (n = 7) and control group (n = 10). The training group performed a 12-week resistance training programme 3 d.wk-1, with the following exercises: bench press, leg extension, pull-down, leg curl, biceps curl, seated calf raise, pushdown and crunch. The control group performed 12 weeks of passive stretching training 2 d.wk-1. Body composition, maximal strength, resting blood pressure, blood variables and functional capacity were assessed before and after the training period. Results : There were significant changes (p<0.05) in muscular strength in the bench press exercise (28.6 ± 2.1 vs 32.6 ± 2.5 kg) and leg extension (22.7 ± 1.8 vs 26.3 ± 1.8 kg) and agility tests (6.0 ± 0.2 vs 4.6 ± 0.2 s), 10-m walk (6.5 ± 0.4 vs 5.5 ± 0.3 s) and lower limbs endurance (16.0 ± 1.0 vs 18.7 ± 1.8 rps). Also, the training group showed lower values (p<0.05) than the control group in triglycerides (79.5 ± 13.6 vs 137.3 ± 17.8 mg.dL-1) and blood glucose (85.2 ± 1.9 vs 95.0 ± 2.8 mg.dL-1) at post-training. No significant changes were identified in resting blood pressure and body composition. Conclusion : Twelve weeks of resistance training were sufficient to increase muscle strength and functional capacity of hypertensive elderly, but without statistically modifying the values of resting blood pressure, body composition and blood variables.
Background : A recent, novel approach to measuring training load has been to investigate measures of the post-exercise return towards resting homeostasis for potential in this role. For practical reasons, it is important to determine whether changes in training load produce changes in the recovery measurement that are in excess of the day-to-day variation or within-subject reliability of the measurement. However, the day-to-day variation in certain recovery measurements is not always known. Research objective : To determine day-to-day variation in measures of heart rate recovery (HRR) and excess post-exercise oxygen consumption (EPOC) so as to determine the minimal detectable difference in these measurements for future research. Type of study : Observational cohort study. Methods : Twelve moderately trained runners completed 3 repetitions of a submaximal treadmill protocol on consecutive days. The protocol involved 20 min of running at 70% of maximal oxygen uptake and 15 min of controlled recovery. Day-to-day variation for exercise and recovery measurements was calculated as the typical error as a coefficient of variation (CVTEM). Results : Recovery measurements showed CVTEM values of 8.0% (90% C.I. 6.7-10.3%) for the magnitude of EPOC, 12.9% (90% C.I. 10.6-16.4%) for the time constant of the oxygen consumption recovery curve, 8.7% (90% C.I. 7.2-11.2%) for 1 min HRR and 10.0% (90% C.I. 8.2-12.8%) for the time constant of the HRR curve. In contrast, most exercise parameters had CVTEM values of 2-4%. Conclusions : For future studies in a similar setting, changes in training load that produce changes in HRR or EPOC greater than the CVTEM values of these recovery measurements might be interpreted as of likely practical significance.
Background : There is no recent scientific information available on the perceptions of active and former professional football players on medical examinations during and after their careers. Research question : The aim of this study was to explore which kind of medical examinations are currently addressed during and after a career as professional football player in the Netherlands and what are the needs towards improvement in these medical examinations. Type of study : cross sectional study. Methods : A qualitative research was conducted based on semi-structured, audio-recorded telephone interviews with eight active professional football players, eight former professional football players and eight club physicians. Results : At present, the contents of medical examinations are directed to the cardiovascular, pulmonary and musculoskeletal systems. All three target groups criticize the current organization and content of the medical examinations. After a career in professional football, sport-specific medical examinations are still lacking. Proposals were done focusing more on the prevention of physical and psychosocial problems preferably organized more centrally. Conclusion : The content of the current medical examinations in Dutch professional football is criticized by all participant groups. Recommendations were made towards improvements of the medical examinations during and after the career of a professional football player, especially with regard to the prevention of potential long-term health problems. Centrally organized medical examinations for former professional football players were proposed.
Background : This study aimed to determine: 1) the changes in the physical conditioning of under-19 soccer players, 2) the effects of strength training using resistance executed as a function of the speed of a Smith machine bar, 3) relationships between heart rate (HR) values recorded during training and competition and changes in players' physical conditioning. Methods : Nineteen field players from a team in the U-19 Spanish first division participated in the study. Changes in jump ability (CMJ, CMJL), bar movement speed in a loaded full squat (FSL), sprint time over 30m (T10, T20, T30, T10-20, T10-30, T20-30), and maximal aerobic speed (MAS) were evaluated three times (E1, E2, E3) during the fourth months studied. Players' HR during practices and matches were recorded. Improvements in MAS, application of strength in CMJ, CMJL, and FSL were reported, while the players significantly worsening their sprint times. Results : No significant relationships were found between HR values and changes in players' physical conditioning. Changes in sprint times (T30 and T10-30) were correlated with changes in bar speed for the FS60kg (r = 0.53-0.64, p < 0.05) and volume of strength training performed (r = 0.53-0.59, p < 0.05). These improvements in strength did not induce expected improvement in sprint time, possibly due to the interference effect between concurrent aerobic and strength training. Conclusions : The results suggests that improved ability to accelerate could be related to improvements in loaded full squats moving at speed near 1m.s-1, and the inhibitor effect obtained shows the importance of monitoring the intensity of aerobic training.
