Pre-season Period Research Articles

Do Australian Football players have sensitive groins? Players with current groin pain exhibit mechanical hyperalgesia of the adductor tendon.

This is the first study to evaluate the mechanical sensitivity, clinical classifications and prevalence of groin pain in Australian football players. Case-control. Professional (n=66) and semi-professional (n=9) Australian football players with and without current or previous groin injuries were recruited. Diagnoses were mapped to the Doha Agreement taxonomy. Point and career prevalence of groin pain was calculated. Pressure pain thresholds (PPTs) were assessed at regional and distant sites using handheld pressure algometry across four sites bilaterally (adductor longus tendon, pubic bone, rectus femoris, tibialis anterior muscle). To assess the relationship between current groin pain and fixed effects of hyperalgesia of each site and a history of groin pain, a mixed-effect logistic regression model was utilised. Receiver Operator Characteristic (ROC) curve were determined for the model. Point prevalence of groin pain in the preseason was 21.9% with a career prevalence of 44.8%. Adductor-related groin pain was the most prevalent classification in the pre-season period. Hyperalgesia was observed in the adductor longus tendon site in athletes with current groin pain (OR=16.27, 95% CI 1.86 to 142.02). The ROC area under the curve of the regression model was fair (AUC=0.76, 95% CI 0.54 to 0.83). Prevalence data indicates that groin pain is a larger issue than published incidence rates imply. Adductor-related groin pain is the most common diagnosis in pre-season in this population. This study has shown that hyperalgesia exists in Australian football players experiencing groin pain indicating the value of assessing mechanical pain sensitivity as a component of the clinical assessment.

RISK OF SPORTS-RELATED MUSCULOSKELETAL INJURIES AMONG ELITE WOMEN BASKETBALL PLAYERS ACCORDING TO POSITION ON THE COURT AND SPORT RESULTS

Background. Basketball is a popular sport around the world, the number of players is growing, the probability to experience trauma is increasing, too. Studies have shown that women sustain 60% more injuries than men do. Pre- season physical examination helps to establish sports specific changes in the body of the athlete and to determine risk factors for training, competition, which cause injury to the players. Research aim was to analyse risk of non-contact musculoskeletal injuries in elite women basketball players according to the position on the court. Methods. The study involved 100 players in Lithuanian women basketball league who completed the questionnaire about the level of physical fatigue, performed Lower Quarter Y Balance Test™ and Functional Movement Screen ™ tests during pre-season physical examination in 2014. Data were analysed and compared according to player’s position on the court (guards and forwards). Results. The level of physical fatigue during pre-season period was low in both groups. Dynamic stability of the right leg was better in guards (composite score – 105.2 to 101.8 in forwards) while dynamic stability of the left leg remained the same in both groups. Guards had higher total scores in Functional Movement Screen™ tests pointing to the better quality of basic functional movement patterns. Conclusions. The guard’s playing efficiency during the season was higher than that of forwards and it was associated with better dynamic stability and higher level of physical fatigue at pre-season. Indirect indicators of non-contact musculoskeletal sport injuries showed that guards should have lower risk of non-contact sport-related injuries in women basketball.

Physical Profiles of Regional Academy Netball Players

Objectives: The purpose of this study was to evaluate the height, body mass and physical characteristics of English regional acad emy netball players by age category (under 15s, under 17s and under 19s). Design and Methods: Data were collected on 50 regional academy players during the preseason period and comprised of height, body mass, and physical (single and triple hop, 5- and 10-m sprint, 505 change of direction speed, vertical jump, and cardiorespiratory fitness) characteristics. Results: One-way analysis of variance revealed the under 19s group demonstrated superior (p < 0.05) performances compared to the under 15s group in single hop left (U15: 1.61 ± 0.18 m; U19: 1.88 ± 0.09 m; p = 0.001), single hop right (U15: 1.66 ± 0.17 m; U19: 1.87 ± 0.13 m; p = 0.001), triple hop left (U15: 5.10 ± 0.58 m; U19: 5.90 ± 0.39 m; p = 0.001), triple hop right (U15: 5.10 ± 0.50 m; U19: 5.86 ± 0.41 m; p = 0.001), 5-m sprint (U15: 1.15 ± 0.05 seconds; U19: 1.10 ± 0.07 seconds; p = 0.032), 505 left (U15: 2.59 ± 0.08 seconds; U19: 2.45 ± 0.08 seconds; p = 0.001), 505 right (U15: 2.54 ± 0.13 seconds; U19: 2.43 ± 0.06 seconds; p = 0.007), squat jump (U15: 0.34 ± 0.04 m; U19: 0.41 ± 0.05 m; p = 0.001), countermovement jump (U15: 0.35 ± 0.04 m; U19: 0.42 ± 0.05 m; p = 0.001), and cardiorespiratory fitness (U15: 16.40 ± 0.83 km∙hˉ¹; U19: 18.14 ± 1.10 km∙hˉ¹; p = 0.001). Moreover, the under 17s group reported significantly better (p < 0.05) performances in single leg hop left (U15: 1.61 ± 0.18 m; U17: 1.74 ± 0.12 m; p = 0.033), single hop right, triple hop left (U15: 5.10 ± 0.58 m; U17: 5.59 ± 0.35 m; p = 0.008), triple hop right (U15: 5.10 ± 0.50 m; U17: 5.50 ± 0.36 m; p = 0.031), countermovement jump (U15: 0.35 ± 0.04 m; U17: 0.39 ± 0.03 m; p = 0.018), and cardiorespiratory fitness (U15: 16.40 ± 0.83 km∙hˉ¹; U17: 17.56 ± 1.30 km∙hˉ¹; p = 0.014) than the under 15s group. Conclusions: These findings highlight that height, body mass, and physical characteristics develop across age categories and pro vide normative data for English regional academy netball players.

Relationship between pre-season strength and power measures and performance in elite Australian football

This study investigated the relationship between various measures of muscular strength and power and individual player performance in elite Australian football (AF). Strength and power data was collected from 30 players from one Australian Football League club at various time points over the 2014 pre-season period. Upper and lower body strength and power were assessed using a one repetition maximum bench press, isometric mid-thigh pull and loaded countermovement jumps respectively. These variables were related to individual performance indicators (Champion Data ranking and descriptive match statistics) averaged over 22 games of the 2014 regular season. A secondary analysis also correlated strength and power measures with high speed running data derived from GPS units worn during games. For all players combined, no significant relationships for strength measures were found with Champion data ranking, but some power measures recorded moderate-large inverse relationships (r = -0.38 to -0.61) with certain match statistics. When separated by position, strong positive associations (r = 0.51 to 0.73) between upper body strength and performance (Champion Data© ranking and match statistics) were recorded for nomadic (midfield) players, but not for non-nomadic (taller, set position) players. Lower body power was also moderately-strongly associated (r = 0.42-0.69) with (GPS) maximum game acceleration and speed for the nomadic and combined player groups. These findings suggest that strength and power are significantly related to some common AF performance indicators and that particular consideration should be given to the positional requirements of players in planning strength and power programmes.

Temperature, precipitation, and insolation effects on autumn vegetation phenology in temperate China.

Autumn phenology plays a critical role in regulating climate-biosphere interactions. However, the climatic drivers of autumn phenology remain unclear. In this study, we applied four methods to estimate the date of the end of the growing season (EOS) across China's temperate biomes based on a 30-year normalized difference vegetation index (NDVI) dataset from Global Inventory Modeling and Mapping Studies (GIMMS). We investigated the relationships of EOS with temperature, precipitation sum, and insolation sum over the preseason periods by computing temporal partial correlation coefficients. The results showed that the EOS date was delayed in temperate China by an average rate at 0.12 ± 0.01 days per year over the time period of 1982-2011. EOS of dry grassland in Inner Mongolia was advanced. Temporal trends of EOS determined across the four methods were similar in sign, but different in magnitude. Consistent with previous studies, we observed positive correlations between temperature and EOS. Interestingly, the sum of precipitation and insolation during the preseason was also associated with EOS, but their effects were biome dependent. For the forest biomes, except for evergreen needle-leaf forests, the EOS dates were positively associated with insolation sum over the preseason, whereas for dry grassland, the precipitation over the preseason was more dominant. Our results confirmed the importance of temperature on phenological processes in autumn, and further suggested that both precipitation and insolation should be considered to improve the performance of autumn phenology models.

Relationship Between Dietary Factors and Bodily Iron Status Among Japanese Collegiate Elite Female Rhythmic Gymnasts.

This cross-sectional study explored the prevalence of iron deficiency (ID) and associations between dietary factors and incidence of ID in female rhythmic gymnasts during preseason periods. Participants were 60 elite collegiate rhythmic gymnasts (18.1 ± 0.3 years [M ± SD]) who were recruited every August over the course of 8 years. Participants were divided into 2 groups according to the presence or absence of ID. Presence of ID was defined either by ferritin less than 12 μg/L or percentage of transferrin saturation less than 16%. Anthropometric and hematologic data, as well as dietary intake, which was estimated via a semiquantitative food frequency questionnaire, were compared. ID was noted in 48.3% of participants. No significant group-dependent differences were observed in physical characteristics, red blood cell counts, hemoglobin, hematocrit, haptoglobin, or erythropoietin concentrations. The ID group had a significantly lower total iron-binding capacity; serum-free iron; percentage of transferrin saturation; ferritin; and intake of protein, fat, zinc, vitamin B2, vitamin B6, beans, and eggs but not iron or vitamin C. The recommended dietary allowance for intake of protein, iron, zinc, and various vitamins was not met by 30%, 90%, 70%, and 22%-87% of all participants, respectively. Multiple logistic analysis showed that protein intake was significantly associated with the incidence of ID (odds ratio = 0.814, 95% confidence interval [0.669, 0.990], p = .039). Participants in the preseason's weight-loss periods showed a tendency toward insufficient nutrient intake and were at a high risk for ID, particularly because of lower protein intake.

Anthropometric and Physical Profiles of English Academy Rugby Union Players.

The purpose of this study was to evaluate the anthropometric and physical characteristics of English regional academy rugby union players by age category (under 16s, under 18s and under 21s). Data were collected on 67 academy players at the beginning of the preseason period and comprised anthropometric (height, body mass, and sum of 8 skinfolds) and physical (5-, 10-, 20-, and 40-m sprint, acceleration, velocity, and momentum; agility 505; vertical jump; Yo-Yo intermittent recovery test level 1; 30-15 intermittent fitness test; absolute and relative 3 repetition maximum front squat, split squat, bench press, prone row, and chin; and isometric mid-thigh pull). One-way analysis of variance demonstrated significant increases across the 3 age categories (p ≤ 0.05) for height (e.g., 16s = 178.8 ± 7.1; 18s = 183.5 ± 7.2; 21s = 186.7 ± 6.61 cm), body mass (e.g., 16s = 79.4 ± 12.8; 18s = 88.3 ± 11.9; 21s = 98.3 ± 10.4 kg), countermovement jump height and peak power, sprint momentum, velocity, and acceleration; absolute, relative, and isometric (e.g., 16s = 2,157.9 ± 309.9; 18s = 2,561.3 ± 339.4; 21s = 3,104.5 ± 354.0 N) strength. Momentum, maximal speed, and the ability to maintain acceleration were all discriminating factors between age categories, suggesting that these variables may be more important to monitor rather than sprint times. These findings highlight that anthropometric and physical characteristics develop across age categories and provide comparative data for English Academy Rugby Union players.

Achilles tendon structure improves on UTC imaging over a 5-month pre-season in elite Australian football players.

Pre-season injuries are common and may be due to a reintroduction of training loads. Tendons are sensitive to changes in load, making them vulnerable to injury in the pre-season. This study investigated changes in Achilles tendon structure on ultrasound tissue characterization (UTC) over the course of a 5-month pre-season in elite male Australian football players. Eighteen elite male Australian football players with no history of Achilles tendinopathy and normal Achilles tendons were recruited. The left Achilles tendon was scanned with UTC to quantify the stability of the echopattern. Participants were scanned at the start and completion of a 5-month pre-season. Fifteen players remained asymptomatic over the course of the pre-season. All four echo-types were significantly different at the end of the pre-season, with the overall echopattern suggesting an improvement in Achilles tendon structure. Three of the 18 participants developed Achilles tendon pain that coincided with a change in the UTC echopattern. This study demonstrates that the UTC echopattern of the Achilles tendon improves over a 5-month pre-season training period, representing increased fibrillar alignment. However, further investigation is needed to elucidate with this alteration in the UTC echopattern results in improved tendon resilience and load capacity.

Differences in Lower-Body Stiffness Between Levels of Netball Competition

There are many notable differences in physical and skill attributes between competition levels, especially in team sports. Stiffness is an important mechanical factor to measure when considering athletic performance and injury incidence. Active vertical stiffness (K(vert)) during hopping and passive stiffness during lying and standing were measured during the preseason period for 46 female netballers (24.0 ± 3.7 years, 72.2 ± 7.6 kg, 175.2 ± 6.7 cm). Participants were classified as elite, sub-elite, representative or recreational based on their current level of competition. A 1-way analysis of variance revealed that elite players possessed significantly higher K(vert) than recreational players (p = 0.018). Large effect sizes (ES) suggested that elite players also possessed higher K(vert) than sub-elite (d = 1.11) and representative (d = 1.11) players. A number of large and moderate ES were also present when comparing the passive stiffness of elite players to their lower-ranked counterparts. The results of this study suggest that elite players possess higher levels of active stiffness when compared with their lower-ranked counterparts. The differences in stiffness levels may contribute to a player's ability to physically perform at an elite level and also provide one explanation into elevated rates of injury at higher levels of competition.

Half-squat or jump squat training under optimum power load conditions to counteract power and speed decrements in Brazilian elite soccer players during the preseason

The purpose of this study was to test which specific type of exercise (i.e., jump squat (JS) or half-squat (HS)) is more effective at maintaining speed and power abilities throughout a preseason in soccer players. Twenty-three male soccer players were randomly allocated into two groups: JS and HS. The mean propulsive power, vertical jumping ability, and sprinting performance were evaluated before and after 4 weeks of a preseason period. The optimum power loads for the JS and HS exercises were assessed and were used as load-references. The soccer players performed 10 power oriented training sessions in total. Both JS and HS maintained power in JS and speed abilities (P > 0.05, for main effects and interaction effect) as indicated by ANCOVA. Both groups demonstrated reduced power during HS (ES = −0.76 vs. −0.78, for JS and HS, respectively); both groups improved acceleration (ACC) from 5 to 10 m (ES = 0.52). JS was more effective at reducing the ACC decrements over 0–5 m (ES = −0.38 vs. −0.58, for JS and HS, respectively). The HS group increased squat jump height (ES = 0.76 vs. 0.11, for HS and JS, respectively). In summary, JS is more effective in reducing the ACC capacity over very short sprints while HS is more effective in improving squat jump performance. Both strategies improve ACC over longer distances. New training strategies should be implemented/developed to avoid concurrent training effects between power and endurance adaptations during professional soccer preseasons.

Relationship between physical capacity and match performance in semiprofessional Australian rules football.

This study investigated the relationship between physical performance and match performance in Australian Rules Football (ARF). Thirty-six semiprofessional ARF players participated in this study. Physical capacity was measured using a 3-km time trial. Match performance was measured throughout the 2013 season through 2 methods: direct game involvements (DGIs) per minute and a recording of coaches' vote after the game. The main finding of the study was that 3-km time trial performance was a significant predictor of DGI per minute (p ≤ 0.05). In addition, the number of senior games played was also significant in predicting DGI per minute (p ≤ 0.05). Furthermore, the number of senior games significantly correlated with coaches' votes (p ≤ 0.05). There were no significant relationships between 3-km time trial and coaches' vote. The results highlight the importance of developing physical capacity in the preseason period; the players who were better performers in the 3-km time trial had a greater number of DGIs per minute. This information is important to consider in preseason planning to ensure sufficient time is dedicated to developing physical capacity in the training program, as it is directly associated with performance. In addition, this research also highlights the importance of playing experience in relation to team selection. Playing experience, as measured by the number of senior games played, had a significant relationship with both measures of match performance.

Quantification of training load, energy intake, and physiological adaptations during a rugby preseason: a case study from an elite European rugby union squad.

Rugby Union (RU) is a high-speed collision sport consisting of an intermittent activity profile. Given the extreme physical demands of the sport, significant emphasis is placed on players possessing high lean body mass while minimizing body fat. Anecdotally, the most significant changes in body composition are observed during the preseason; however, there are no objective data on the physiological demands and energy intake during this time. We therefore monitored 45 elite European RU players over the 10-week preseason period by assessing training load using Global Positioning System and session rate of perceived exertion (sRPE) while also assessing changes in anthropometry and physical performance. For forwards and backs, respectively, mean weekly distance covered was 9,774 m (1,404) and 11,585 m (1,810) with a total mean weekly sRPE of 3,398 (335) arbitrary units and 2,944 (410) arbitrary units. Mean daily energy intake was 14.8 MJ (1.9) and 13.3 MJ (1.9), carbohydrate (CHO) intake was 3.3 (0.7) and 4.14 (0.4) g·kg body mass, protein intake was 2.52 (0.3) and 2.59 (0.6) g·kg body mass, and fat intake was 1.0 (0.3) and 0.95 (0.3) g·kg body mass for forwards and backs, respectively. Markers of physical performance (1 repetition maximum strength, speed, and repeated sprint tests) and anthropometry (body fat and estimated lean mass) improved in all players. Interestingly, all players self-selected a "low" CHO "high" protein diet. Based on physiological improvements the training load and energy intake seems appropriate, although further research is required to evaluate if such energy intakes would also be suitable for match day performance.

Junior cricketers are not a smaller version of adult cricketers: A 5-year investigation of injuries in elite junior cricketers

Background. Injury surveillance is fundamental to preventing and reducing the risk of injury. Objectives. To determine the incidence of injuries and the injury demographics of elite schoolboy cricketers over five seasons (2007 - 2008, 2008 - 2009, 2009 - 2010, 2010 - 2011 and 2011 - 2012). Methods. Sixteen provincial age group cricket teams (under (U) 15 , U17 and U18) competing in national age-group tournaments were provided a questionnaire to complete. The questionnaires gathered the following information for each injury sustained in the previous 12 months: (i) anatomical site; (ii) month; (iii) cause; (iv) whether it was a recurrence of an injury from a previous season; (v) whether the injury had reoccurred during the current season; and (vi) biographical data. Injuries were grouped according to the anatomical region injured. All players were invited to respond, irrespective of whether an injury had been sustained, resulting in a response rate of 57%. The sample Statistical Analysis System was used to compute univariate statistics and frequency distributions. Results. Of the 2 081 respondents, 572 (27%) sustained a total of 658 injuries. The U15 and U17 groups sustained 239 (36%) and 230 (35%) injuries, respectively, more than the 189 injuries sustained by the U18 group (29%). These injuries were predominantly to the lower limbs (38%), back and trunk (33%) and upper (26%) limbs, with 3% occurring to the head and neck. The injuries occurred primarily during 1-day matches (30%), practices (29%) and with gradual onset (21%). The primary mechanism of injury was bowling (44%) and fielding (22%). The injuries were acute (49%), chronic (41%) and acute-on-chronic (10%), with 26% and 47% being recurrent injuries from the previous and current seasons, respectively. Some similar injury patterns occurred in studies of adult cricketers, with differences in the nature and incidence of injuries found for the various age groups. The youth cricketers sustained more back and trunk injuries, recurrent injuries and more match injuries than the adult cricketers. The U15 group sustained less-serious injuries, which resulted in them not being able to play for between 1 and 7 days (58%), with more injuries occurring in the preseason period (24%) and fewer during the season (60%) compared with other age groups. The U15 and U17 groups sustained the most lumbar muscle strains, while the U18 groups sustained more serious injuries, resulting in them not being able to play for &gt;21 days. Conclusion. Young fast bowlers of all ages remain at the greatest risk of injury. Differences in the nature and incidence of injuries occurred between youth and adult cricketers, as well as in the different age groups. It is recommended that cricket administrators and coaches implement an educational process of injury prevention and management

Seasonal training-load quantification in elite English premier league soccer players.

To quantify the seasonal training load completed by professional soccer players of the English Premier League. Thirty players were sampled (using GPS, heart rate, and rating of perceived exertion [RPE]) during the daily training sessions of the 2011-12 preseason and in-season period. Preseason data were analyzed across 6×1-wk microcycles. In-season data were analyzed across 6×6-wk mesocycle blocks and 3×1-wk microcycles at start, midpoint, and end-time points. Data were also analyzed with respect to number of days before a match. Typical daily training load (ie, total distance, high-speed distance, percent maximal heart rate [%HRmax], RPE load) did not differ during each week of the preseason phase. However, daily total distance covered was 1304 (95% CI 434-2174) m greater in the 1st mesocycle than in the 6th. %HRmax values were also greater (3.3%, 1.3-5.4%) in the 3rd mesocycle than in the first. Furthermore, training load was lower on the day before match (MD-1) than 2 (MD-2) to 5 (MD-5) d before a match, although no difference was apparent between these latter time points. The authors provide the 1st report of seasonal training load in elite soccer players and observed that periodization of training load was typically confined to MD-1 (regardless of mesocycle), whereas no differences were apparent during MD-2 to MD-5. Future studies should evaluate whether this loading and periodization are facilitative of optimal training adaptations and match-day performance.

Increase in Injury Risk With Low Body Mass and Aerobic-Running Fitness in Elite Australian Football

To assess the relationships between player characteristics (including age, playing experience, ethnicity, and physical fitness) and in-season injury in elite Australian football. Single-cohort, prospective, longitudinal study. Player characteristics (height, body mass, age, experience, ethnicity, playing position), preseason fitness (6-min run, 40-m sprint, 6×40-m sprint, vertical jump), and in-season injury data were collected over 4 seasons from 1 professional Australian football club. Data were analyzed for 69 players, for a total of 3879 player rounds and 174 seasons. Injury risk (odds ratio [OR]) and injury severity (matches missed; rate ratio [RR]) were assessed using a series of multilevel univariate and multivariate hierarchical linear models. A total of 177 injuries were recorded with 494 matches missed (2.8±3.3 matches/injury). The majority (87%) of injuries affected the lower body, with hamstring (20%) and groin/hip (14%) most prevalent. Nineteen players (28%) suffered recurrent injuries. Injury incidence was increased in players with low body mass (OR=0.887, P=.005), with poor 6-min-run performance (OR=0.994, P=.051), and playing as forwards (OR=2.216, P=.036). Injury severity was increased in players with low body mass (RR=0.892, P=.008), tall stature (RR=1.131, P=.002), poor 6-min-run (RR=0.990, P=.006), and slow 40-m-sprint (RR=3.963, P=.082) performance. The potential to modify intrinsic risk factors is greatest in the preseason period, and improvements in aerobic-running fitness and increased body mass may protect against in-season injury in elite Australian football.

A prospective epidemiological study of injury incidence and injury patterns in a Hong Kong male professional football league during the competitive season

The aim of this study was to investigate the match and training injury incidence, injury patterns and severity, and their monthly variation in a Hong Kong male professional football league. The study design was a prospective cohort study. Seven teams in the Hong Kong Football Association first division league and 152 players from 10 professional teams participated in this study. On a weekly basis throughout the 9-month season, time-loss injuries and individual exposure were collected from injury recorders team visits. Operational injury definitions and procedures followed the recommendations of a football consensus. The overall injury incidence was 7.4 injuries/1000 player hours and 296 injuries were recorded. The relative risk of match injury was 17 times greater than the risk of training injury [relative ratio (RR), 17.3; 95% confidence injury (CI), 11.6–25.7; p < 0.001]. Ankle sprain was the most common injury type (16.2% of all injuries) and 52% of these injuries were recurrent. Thigh strain was the second most common injury type with 82% of the injuries involving the hamstring muscle and 80% of hamstring strains were noncontact injuries. During the competitive season, the relative risk of injury was highest in October (RR, 6.8; 95% CI, 6.7–6.9; p < 0.001) and February (RR, 4.7; 95% CI, 4.3–5.2; p < 0.001). This highlighted that Hong Kong professional football has a high match injury incidence. The relative risk of injury was highest at the beginning of the competitive season. A prospective multicentre epidemiological study is warranted to examine regional differences in injury risks. Coaches, players, health professionals, and researchers should join their efforts to investigate the effect on injury incidence and injury pattern associated with the duration and content of the preseason period, and the number of friendly matches held during preseason.

Physiological and performance changes in response to pre-season training in high level handball players

The aim of this study was to evaluate changes of physiological markers and performance, in professional handball players during the pre-season period. Fifteen male players (mean and SD: age 24.0 ± 4.0 years, body mass 89.7 ± 10.1 kg and height 185.2 ± 6.3 cm) participated in this study. The evaluations of physical performance, cardiac autonomic modulation and the collection of blood samples for inflammatory markers were conducted at beginning of pre-season (M 1 ) and 7 weeks after (M 2 ). There were significant increases of performance in the Yo-YoIR2, vertical jumps and significant reduction in TGF-β. Small to large effect size (ES) for changes were detected for SDNN, RMSSD, LF + HF and SD1 indexes. The pre-season period has promoted positive changes in global indices of cardiac autonomic modulation, TGF-β together with an increase of physical performance. Évaluer les changements des marqueurs du stress physiologique et de la performance physique lors de la pré-saison chez des joueurs professionnels de handball. Quinze joueurs masculins (âge : 24,0 ± 4,0 ans, masse : 89,7 ± 10,1 kg et stature : 185,2 ± 6,3 cm) ont participé à cette étude. Les évaluations de la performance, de la modulation cardiaque autonome et des dosages sanguins de marqueurs d’inflammation ont été réalisées au début de la période de pré-saison (M 1 ) et sept semaines après (M 2 ). Les sept semaines d’entraînement ont induit une amélioration des performances physiques au Yo-YoIR2, aux sauts verticaux et une diminution du taux de TGF-β. La différence significative du SDNN et les variations de son amplitude expliquaient les réponses de RMSSD, des indices LF + HF et SD1 entre M 1 et M 2 . La période de pré-saison a un effet positif sur la modulation de système cardiaque autonome, les taux de TGF-β avec une augmentation de la performance physique.

A NOVEL MOBILE DEVICE BASED HAMSTRING STRENGTH TEST RESULT CAN PREDICT ISOKINETIC HAMSTRING STRENGTH IN PROFESSIONAL FOOTBALL PLAYERS: A STUDY OF RELIABILITY AND VALIDITY

BackgroundIsokinetic hamstring strength test is considered as a golden standard for identifying players with increased risk of hamstring strain injuries. However, those testing protocols were time consuming and inconvenient.ObjectiveThe aim...

EVALUATION OF A PROSPECTIVE COHORT STUDY DESIGN OF TRAINING LOAD RISK FACTORS FOR INJURY IN ELITE JUNIOR AUSTRALIAN FOOTBALLERS

BackgroundResearch focused on elite senior Australian Football (AF) competition, during the in-season, has found training load (a measurement of both training intensity and duration) and factors such as cumulative load,...

Combining Internal- and External-Training-Load Measures in Professional Rugby League

This study investigated the effect of training mode on the relationships between measures of training load in professional rugby league players. Five measures of training load (internal: individualized training impulse, session rating of perceived exertion; external-body load, high-speed distance, total impacts) were collected from 17 professional male rugby league players over the course of two 12-wk preseason periods. Training was categorized by mode (small-sided games, conditioning, skills, speed, strongman, and wrestle) and subsequently subjected to a principal-component analysis. Extraction criteria were set at an eigenvalue of greater than 1. Modes that extracted more than 1 principal component were subjected to a varimax rotation. Small-sided games and conditioning extracted 1 principal component, explaining 68% and 52% of the variance, respectively. Skills, wrestle, strongman, and speed extracted 2 principal components each explaining 68%, 71%, 72%, and 67% of the variance, respectively. In certain training modes the inclusion of both internal and external training-load measures explained a greater proportion of the variance than any 1 individual measure. This would suggest that in training modes where 2 principal components were identified, the use of only a single internal or external training-load measure could potentially lead to an underestimation of the training dose. Consequently, a combination of internal- and external-load measures is required during certain training modes.