Latest research in football - week 19 - 2017

As previous literature updates, I have performed a PubCrawler search looking for football articles in NCBI Medline (PubMed) and GenBank databases.

Following studies were retrieved for this week:

#1 The Effects of Sleep Deprivation on Soccer Skills
Reference: Percept Mot Skills. 2017 Jan 1:31512517707412. doi: 10.1177/0031512517707412. [Epub ahead of print]
Authors: Pallesen S, Gundersen HS, Kristoffersen M, Bjorvatn B, Thun E, Harris A
Summary: Many athletes sleep poorly due to stress, travel, and competition anxiety. In the present study, we investigated the effects of sleep deprivation on soccer skills (juggling, dribbling, ball control, continuous kicking, 20 and 40 m sprint, and 30 m sprint with changes of direction). In all, 19 male junior soccer players (14-19 years old) were recruited and participated in a cross-balanced experimental study comprising two conditions; habitual sleep and 24 hours sleep deprivation. In both conditions, testing took place between 8 a.m. and 10 a.m. Order of tests was counterbalanced. Each test was conducted once or twice in a sequence repeated three times. The results revealed a negative effect of sleep deprivation on the continuous kicking test. On one test, 30 meter sprint with directional changes, a significant condition × test repetition interaction was found, indicating a steeper learning curve in the sleep deprived condition from Test 1 to Test 2 and a steeper learning curve in the rested condition from Test 2 to Test 3. The results are discussed in terms of limitations and strengths, and recommendations for future studies are outlined.


#2 The influence of a 12% carbohydrate-electrolyte beverage on self-paced soccer-specific exercise performance
Reference: J Sci Med Sport. 2017 Apr 21. pii: S1440-2440(17)30399-7. doi: 10.1016/j.jsams.2017.04.015. [Epub ahead of print]
Authors: Harper LD, Stevenson EJ, Rollo I, Russell M
Summary: The purpose was to assess the physiological and performance effects of a 12% carbohydrate-electrolyte beverage consumed at practically applicable time-points (i.e., before each half) throughout simulated soccer match-play. Fed players (n=15) performed 90-min of soccer-specific exercise (including self-paced exercise at the end of each half). Players consumed carbohydrate-electrolyte (CHO; 60g×500ml-1, Na+ 205mg×500ml-1), placebo-electrolyte (PL) or water (Wat) beverages at the end of the warm-up (250ml) and half-time (250ml plus ad-libitum water). Blood was drawn before each half and every 15-min during exercise. Physical (15-m sprinting, countermovement jumps, self-paced distance, acceleration/deceleration count), technical (dribbling) and cognitive (memory, attention, decision-making) performance was assessed. Ratings of perceived exertion (RPE) and abdominal discomfort were measured. Against Wat and PL, CHO increased (all p<0.05) mean accelerations >1.5m·s-2 during self-paced exercise (>+25%) and dribbling speed from 60-min onwards (>+3%). Mean sprinting speed improved (+2.7%) in CHO versus Wat. Blood glucose increased before and during each half in CHO versus PL and Wat (all p<0.05). A 27% decline in glycaemia occurred at 60-min in CHO. RPE was comparable between trials. Cognition reduced post-exercise (p<0.05); this decline was not attenuated by CHO. Abdominal discomfort increased during exercise but was similar between trials. Using more realistic fluid ingestion timings than have been examined previously, consuming a 12% carbohydrate-electrolyte beverage increased blood glucose, self-paced exercise performance, and improved dribbling speed in the final 30-min of exercise compared to water and placebo. Carbohydrates did not attenuate post-exercise reductions in cognition.


#3 Profile of match performance and heart rate response in Japanese amputee soccer
Reference: J Sports Med Phys Fitness. 2017 May 5. doi: 10.23736/S0022-4707.17.07246-2. [Epub ahead of print]
Authors: Maehana H, Miyamoto A, Koshiyama K, Tanaka Yanagiya T, Yoshimura M
Summary: The purpose of this study was to profile the match performance and heart rate response in Japanese amputee soccer. Twelve amputee soccer players participated in this study. Match data were collected 20 samples in 4 matches. Match performances data such as total distance, high-intensity running (HIR: ≥13km·h-1) were collected using a global positioning systems technology. Heart rate (HR) was recorded using short-range radio telemetry. In addition, the rating of perceived exertion (RPE) was assessed immediately using Borg's original after the first half and the second half. This study showed that the distance covered over the 50 minutes of the match was 2984.2±56.1m, and it was significantly shorter in the second half than the first half (p<0.05). The distance covered by HIR was 205.3±100.5m, and there was no significant difference between the first half and the second half. Moreover, the mean HR during match was 176.8±7.9beats·min-1, which corresponded to 96.3% of HRmax. RPE was a high value of more 15 in both of the first half and the second half. This study was the first to evaluate competitive performance during matches in amputee soccer. Results of this study indicated that the exercise intensity was high in amputee soccer. It would be considered that causes were amputee soccer own rules and exercise style. These findings would serve as the reference when advance the future studies of amputee soccer.


#4 Reliability of concentric and eccentric strength of hip abductor and adductor muscles in young soccer players
Reference: Biol Sport. 2015 Dec;32(4):351-356. doi: 10.5604/20831862.1189202. Epub 2015 Dec 29.
Authors: Gerodimos V, Karatrantou K, Paschalis V, Zafeiridis A, Katsareli E, Bilios P, Kellis S
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5394850/pdf/JBS-32-1189202.pdf
Summary: The concentric and eccentric strength profile and muscular balance of the hip joint are important parameters for success in soccer. This study evaluated the reliability for the assessment of hip abduction and adduction isokinetic strength over a range of angular velocities (30 and 90°/s) and types of muscular actions (concentric and eccentric) in young soccer players. The reliability for the assessment of reciprocal (conventional and functional) and bilateral torque ratios was also examined. Fifteen male soccer players (15±1 years) performed two sessions, separated by three days. The testing protocol consisted of five maximal concentric and eccentric hip abductions and adductions of both legs at angular velocities of 30°/s and 90°/s. The peak torque was evaluated in young soccer players using an isokinetic dynamometer (Cybex Norm), and the reciprocal strength ratios (conventional and functional) and bilateral ratios (non-preferred to preferred leg ratios) were calculated. The test-retest reliability for the assessment of peak torque (ICC = 0.71-0.92) and of reciprocal muscle group ratios (ICC = 0.44-0.87) was found to be moderate to high. Bilateral torque ratios exhibited low to moderate reliability (ICC = 0.11-0.64). In conclusion, isokinetic strength of hip abductor and adductor muscles and the conventional and functional strength ratios can be reliably assessed in young soccer players, especially at low angular velocities. The assessment, however, of bilateral strength ratios for hip abductor/adductor muscles should be interpreted with more caution.


#5 Implication of dynamic balance in change of direction performance in young elite soccer players is angle dependent?
Reference: J Sports Med Phys Fitness. 2017 Apr 26. doi: 10.23736/S0022-4707.17.06752-4. [Epub ahead of print]
Authors: Rouissi M, Haddad M, Bragazzi NL, Owen AL, Moalla W, Chtara M, Chamari K
Summary: Team sports require rapid whole body change of direction (COD) in order to regain, maintain possession of the ball or to avoid opponent. These actions are often performed through unilateral process, with the contralateral leg incurring no ground contact. As a result, maintaining unilateral dynamic balance remains important. The aim of this study was to examine the relationship between dynamic balance (DB) and (COD) performance in young elite soccer players. 20 right-footed young elite soccer players (age=16.42±0.55 year, height=176±2.5cm; leg length=95.70±3.34cm, body-mass=67.03±5.20kg) participated in this study. All players performed star excursion balance test (SEBT) with dominant (DL) and nondominant leg (NDL). 10m sprint with COD of 45°, 90°, 135° or 180° after 5m were also assessed with COD on both right and left sides. Correlations analysis showed significant negative relationships (moderate to high) between COD tests (with DL and NDL) and some selected reaching directions of the SEBT. Stepwise multiple regression analysis showed that DB performance explained between 20% and 75% of the variance of COD tests. Likewise, dynamic balance contribution was dependent upon the angle of COD and the leg used to turn. Some selected reaching directions of the SEBT were significantly correlated with COD's performance in young elite soccer players which, possibly due to similarities in movement demands and muscle recruitment. Furthermore, the contribution of dynamic balance on COD performance was angle dependent and individualized specific dynamic stability exercises may be required to compensate players' deficit in each COD angle.


#6 Effect of a specialized injury prevention program on static balance, dynamic balance and kicking accuracy of young soccer players
Reference: World J Orthop. 2017 Apr 18;8(4):317-321. doi: 10.5312/wjo.v8.i4.317. eCollection 2017 Apr 18.
Authors: Dunsky A, Barzilay I, Fox O
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5396016/pdf/WJO-8-317.pdf
Summary: The purpose was to study the effect of balance intervention program using the "FIFA 11+" program on static and dynamic balance and kicking accuracy of young soccer players. Twenty young soccer players were allocated to experimental (n = 10) or control (n = 10) groups. The experimental group performed the "FIFA 11+" program three times a week for six weeks. The control group performed their normal warm-up routine. The primary outcomes were measured pre and post intervention, and assessed kicking accuracy, static balance and dynamic balance. No differences were found in kicking accuracy following intervention, for both groups, however, static balance improved significantly among the experimental group with significant interaction with the control group, and with high effect size. In addition, the dynamic balance of the left leg of the experimental group, with medium effect size for interaction between groups. The large effect size of balance improvement that was observed following six weeks of intervention sessions, implies that soccer trainers and coaches should consider the inclusion of "FIFA 11+" as components of programs aimed at improving balance ability/control in young soccer players, as improvement in balance abilities may prevent injuries.


#7 In Place But Not Always Used: Automated External Defibrillators in Amateur Football
Reference: Curr Sports Med Rep. 2017 May/Jun;16(3):126-128. doi: 10.1249/JSR.0000000000000352.
Authors: Vernooij RWM, Goedhart E, Pardo-Hernandez H.


#8 Thunderstorm Asthma, Relative Anemia, and Football Carnage
Reference: Curr Sports Med Rep. 2017 May/Jun;16(3):116-117. doi: 10.1249/JSR.0000000000000349.
Authors: Eichner ER.


#9 Incidence of injury and illness in South African professional male football players: a prospective cohort study
Reference: J Sports Med Phys Fitness. 2017 May 9. doi: 10.23736/S0022-4707.17.07452-7. [Epub ahead of print]
Authors: Bayne H, Schwellnus M, Janse Van Rensburg D, Botha J, Pillay L
Summary: Medical illnesses and sports-related injuries both have an effect on athlete health and performance. Epidemiology of injury and illness has been extensively researched during international football tournaments and the European football season. Reports on injury location and severity differ across geographical regions, and there is limited information on injury epidemiology in African football leagues. No studies have investigated the illness burden in football in Africa. This was a prospective cohort study involving two football teams over the 10- month duration of the 2015/16 Premier Soccer League in South Africa. Team medical staff recorded daily football exposure, illness and injuries. Team-based match and training exposure was calculated and used to determine injury and illness incidence and burden over the football season. Overall injury incidence was 2.2 / 1000 h, with match injury incidence of 24.8 / 1000 h and training injury incidence of 0.9 / 1000 h. Time loss injuries accounted for 33 of the 44 injuries recorded. The most common time loss injury location was the knee (14 injuries, 42%). There were 7 minimal, 4 mild, 12 moderate and 10 severe injuries. Sprain/ligament injury (8 injuries) was the most common type, followed by meniscus/cartilage injury (7 injuries). Eleven illnesses were reported during the season, with an incidence of 0.7 / 1000 player days, and most were minimal in severity (8/11). The illness burden was 1.7 / 1000 player days. The respiratory (46%) and gastrointestinal (36%) systems were most commonly affected. The incidence of injury was comparable with data reported internationally and mirrors the increased risk of injury during matches versus training. The nature of injury differed in that the knee was more frequently affected than the ankle or thigh, joint injuries were more common than muscle injuries, and there was a larger proportion of severe injuries. The illness burden was very low.


#10 Intra-system reliability of SICS: video-tracking system (Digital.Stadium®) for performance analysis in football
Reference: J Sports Med Phys Fitness. 2017 May 9. doi: 10.23736/S0022-4707.17.07267-X. [Epub ahead of print]
Authors: Beato M, Jamil M
Summary: The correct evaluation of external load parameters is a key factor in professional football. The instrumentations usually utilised to quantify the external load parameters during official matches are Video-Tracking Systems (VTS). VTS is a technology that records two- dimensional position data (x and y) at high sampling rates (over 25 Hz). The aim of this study was to evaluate the intra-system reliability of Digital.Stadium® VTS. 28 professional male football players taking part in the Italian Serie A (age 24 ± 6 years, body mass 79.5 ± 7.8 kg, stature 1.83 ± 0.05 m) during the 2015/16 season were enrolled in this study (Team A and Team B). Video-analysis was done during an official match and data analysis was performed immediately after the game ended and then replicated a week later. This study reported a near perfect relationship between the initial analysis (analysis 1) and the replicated analysis undertaken a week later (analysis 2). R2 coefficients were highly significant for each of the performance parameters, p < 0.001. This study reported a mean TD = 8095 ± 3271 and 8073 ± 3263 m in analysis 1 and analysis 2, respectively. Players reported a mean distance covered over 25 w kg-1 equivalent to 1304 ± 673 m and 1294 ± 672 m, and they reported a mean metabolic power of 9.65 ± 1.64 w kg-1 and 9.58 ± 1.61 w kg-1, in analysis 1 and analysis 2, respectively. The findings reported in this study underlined that all data reported by Digital.Stadium® VTS showed high levels of absolute and relative reliability.


#11 Quantitative T2 * relaxation time analysis of articular cartilage of the tibiotalar joint in professional football players and healthy volunteers at 3T MRI
Reference: J Magn Reson Imaging. 2017 May 9. doi: 10.1002/jmri.25757. [Epub ahead of print]
Authors: Behzadi C, Maas KJ, Welsch G, Kaul M, Schoen G, Laqmani A, Adam G, Regier M
Summary: The purpose was to compare T2 * relaxation times of the tibiotalar cartilage between professional football players and matched healthy male volunteers. Twenty-two ankles of professional football players (24.3 ± 3.8 years) and 20 age- and body mass index-matched healthy individuals (25.6 ± 2.4 years) were investigated. The study protocol consisted of multiplanar T1 -weighted, fat-saturated proton-density weighted (Pdw) and a 3D multiecho T2 * sequence with 22 echo times (4.6-53.6 msec). The articular cartilage was subdivided into six segments. Regions of interest were manually drawn in three zones (lateral, central, medial). Differences and confidence intervals were estimated applying a random effects models. Fixed effects were professional football players versus healthy individuals and areas. The random effect was defined as the person cluster of the different individuals. T2 * values were significantly prolonged in football players compared to male volunteers in all predefined cartilage segments (mean, 17.5 vs. 15.5 msec; P < 0.001). In both groups, the highest relaxation times were found in the lateral zone, with statistically higher relaxation times in professional football players (18.5 vs. 16.5 msec, P = 0.003). Separate evaluation revealed the longest relaxation times in the posterior tibiotalar cartilage, with 21.0 msec for professional football players compared to 19.4 msec for healthy volunteers (P = 0.064). Based on these initial results, T2 * values of the tibiotalar cartilage seem to be elevated in professional football players compared to healthy volunteers. Prospective longitudinal studies should be encouraged to show if these results represent early subtle cartilage lesions prior to clinical manifestation or rather temporary adaptation related to daily high-level loading.


#12 Public opinion on alcohol consumption and intoxication at Swedish professional football events

Reference: Subst Abuse Treat Prev Policy. 2017 May 8;12(1):21. doi: 10.1186/s13011-017-0103-8.
Authors: Skoglund C, Durbeej N, Elgan TH, Gripenberg J
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5422961/pdf/13011_2017_Article_103.pdf
Summary: Alcohol-related problems at professional sporting events are of increasing concern and alarming reports are often reported in international media. Although alcohol consumption increases the risk for interpersonal violence, it is viewed as a focal element of large football events. Sweden has a long tradition of high public support for strict alcohol-control policies. However, little is known about public opinions on alcohol intoxication and the support for interventions to decrease intoxication at football events. The current study explored the public opinion towards alcohol use, intoxication and alcohol policies at professional football matches in Sweden. A cross-sectional design was utilized and a random general population sample of 3503 adult Swedish residents was asked to participate in a web survey during 2016 (response rate 68%). In total, 26% of the respondents supported alcohol sales at football events. Over 90% reported that obviously intoxicated spectators should be denied entrance or evicted from arenas. The support for regulations limiting alcohol availability varied with background factors such as gender, alcohol use and frequency of football event attendance.There is a strong public consensus for strategies and policies to reduce alcohol sales and intoxication levels at football matches. This public support has implications for our preventive efforts and will facilitate the implementation of strategies and policy changes.



American Football
#1 The Effect of the Number of Carries Among College Running Backs on Future Injury Risk and Performance in the National Football League

Reference: Orthop J Sports Med. 2017 Apr 21;5(4):2325967117703054. doi: 10.1177/2325967117703054. eCollection 2017 Apr.
Authors: Kraeutler MJ1, Belk JW1, McCarty EC1.
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5405788/pdf/10.1177_2325967117703054.pdfDownload link
Summary: There has been speculation that running backs with an excessive number of carries in college are less likely to be successful in the National Football League (NFL). The purpose was to determine whether there is a correlation between number of carries by college running backs and future performance and injury risk in the NFL. Using the ESPN archives of National Collegiate Athletic Association and NFL running backs, the following inclusion criteria were used: running backs who played their last college season from 1999 through 2012 and who were drafted in the first 4 rounds of the NFL draft following their college career. Players were grouped by number of carries during their final college season (group A, 100-200 carries; group B, 250+ carries). Performance and injury risk were compared between groups during the first 3 eligible seasons in the NFL. Groups were compared based on total number of carries, mean yards per carry, number of games missed due to injury, and the specific injuries resulting in missed playing time. During the seasons studied, a total of 103 running backs were included (group A, n = 42; group B, n = 61). There was a trend toward a significantly greater mean total number of carries through 3 NFL seasons in group B (group A, n = 276 carries; group B, n = 376 carries; P = .058). Mean yards per carry did not differ between groups (group A, n = 3.9 yards/carry; group B, n = 4.0 yards/carry; P = .67). Groups A and B missed a mean 5.8 and 5.7 games, respectively, due to injury during their first 3 NFL seasons (P = .98). A significantly greater proportion of players in group A suffered a concussion compared with group B (P = .014). There is no correlation between the number of carries by college running backs and future injury risk or performance during their early NFL career.


#2 Concussion mechanisms and activities in youth, high school, and college football
Reference: J Neurotrauma. 2017 May 10. doi: 10.1089/neu.2017.5032. [Epub ahead of print]
Authors: Lynall RC, Campbell KR, Wasserman EB, Dompier TP, Kerr Z
Summary: Our purpose was to determine concussion mechanism and activity differences between 3 cohorts of football players; youth, high school, and college. Participants in this prospective cohort study included youth (ages 5-14, 118 teams, 310 team-seasons), high school (96 teams, 184 team-seasons), and college (34 teams, 71 team-seasons) football players. Athletic trainers collected athlete-exposure (AE) and concussion data during the 2012-2014 seasons. Injury mechanism referred to the object that made contact with the concussed player, resulting in the concussion. Injury activity referred to the type of football specific activity the player was involved in when the concussion was sustained. Injury proportion ratios (IPR) compared distributions of concussion mechanisms and activities among age levels. 1,429 concussions were reported over 1,981,284 AE across all levels (Rate: 0.72/1000AE). Overall, most concussions were due to player contact (84.7%). During games, a greater proportion of youth football concussions (14.7%) were due to surface contact than high school (7.3%, IPR=2.02; 95% CI: 1.10-3.72) and college (7.1%, IPR=2.07, 95% CI:1.02-4.23) football. Compared to college football concussions (90.2%), a smaller proportion of youth (80.0%, IPR=0.89, 95%CI: 0.79-0.99) and high school (83.2%, IPR=0.92, 95%CI: 0.86-0.99) football concussions were due to player contact. A greater proportion of game youth football concussions (42.1%) occurred while being tackled than high school (23.2%, IPR=1.81, 95%CI: 1.34-2.45) and college (23.0%, IPR=1.83, 95%CI: 1.29-2.62) football. Findings were similar during practices. Compared to college football game concussions (15.8%), a smaller proportion of youth (6.3%, IPR=0.40, 95%CI: 0.17-0.93) and high school (9.5%, IPR=0.60, 95%CI: 0.38-0.95) football game concussions occurred while being blocked. Concussion mechanism and activity differences should be considered when developing concussion prevention and sport-safety methods specific to different age levels in order to maximize effectiveness.


#3 Consequences of Traumatic Brain Injury in Professional American Football Players: A Systematic Review of the Literature
Reference: Clin J Sport Med. 2017 May 9. doi: 10.1097/JSM.0000000000000432. [Epub ahead of print]
Authors: Vos BC, Nieuwenhuijsen K, Sluiter JK
Summary: The purpose of this study was to systematically review the literature for the consequences Traumatic brain injury (TBI) has on cognitive, psychological, physical, and sports-related functioning in professional American Football players. We performed a systematic search in 2 databases, PubMed and SPORTDiscus, to obtain literature from January 1990 to January 2015. To be eligible for inclusion, a study had to examine the relationship between TBI and the consequences for several aspects of functioning in professional American football players older than 18 years. Methodological quality was assessed using a 5-item checklist which assessed selection bias, information bias, and correct reporting of the population and exposure characteristics. The search yielded 21 studies that met our inclusion criteria. An evidence synthesis was performed on the extracted data and resulted in 5 levels of evidence. The evidence synthesis revealed that there is strong evidence that concussions are associated with late-life depression and short-term physical dysfunctions. Evidence for the relationship between concussion and impaired sports-related function, prolonged reaction time, memory impairment, and visual-motor speed was inconclusive. Moderate evidence was found for the association between TBI and mild cognitive impairment (MCI), and limited evidence was found for the association between TBI and executive dysfunction. There is strong evidence that a history of concussion in American football players is associated with depression later in life and short-term physical dysfunctions. Also cognitive dysfunctions such as MCI are seen in older players with a history of TBI. These results provide input for actions to prevent TBI and their consequences in (retired) American football players


#4 Relationship between Pre-Training Subjective Wellness Measures, Player Load and Rating of Perceived Exertion Training Load in American College Football
Reference: Int J Sports Physiol Perform. 2017 May 10:1-19. doi: 10.1123/ijspp.2016-0714. [Epub ahead of print]
Authors: Govus AD, Coutts A, Duffield R, Murray A, Fullagar H
Summary: The relationship between pre-training subjective wellness, external and internal training load in American College football is unclear. This study examined the relationship between pre-training subjective wellness (sleep quality, muscle soreness, energy, wellness Z score) on 1) player load and 2) session rating of perceived exertion (s-RPE-TL) in American College footballers. Subjective wellness (measured using 5-point, Likert scale questionnaires); external load (derived from global position systems [GPS] and accelerometry) and s-RPE-TL were collected during three typical training sessions per week for the second half of an American collegiate football season (eight weeks). The relationship between pre-training subjective wellness and 1) player load and 2) s-RPE training load were analysed using linear mixed models with a random intercept for athlete and a random slope for training session. Standardised mean differences (SMD) denote the effect magnitude. A one unit increase in wellness Z score and energy were associated with a trivial 2.3% (90% confidence interval (CI): 0.5, 4.2; SMD: 0.12) and 2.6% (90% CI: 0.1, 5.2; SMD: 0.13) increase in player load. A one unit increase in muscle soreness (players felt less sore) corresponded to a trivial 4.4% (90% CI: -8.4, -0.3; SMD: -0.05) decrease in s-RPE training load. Measuring pre-training subjective wellness may provide information about players' capacity to perform within a training session and could be a key determinant of their response to the imposed training demands American College football. Hence, monitoring subjective wellness may assist the individualisation of training prescription in American College footballers.



Australian Football
#1 Factors Affecting Match Outcome in Elite Australian Football: A 14-Year Analysis
Reference: Int J Sports Physiol Perform. 2017 May 10:1-16. doi: 10.1123/ijspp.2016-0450. [Epub ahead of print]
Authors: Lazarus BH, Hopkins WG, Stewart AM, Aughey RJ
Summary: Effects of fixture and team-characteristics on match outcome in elite Australian football were quantified using data accessed at AFLtables.com for 5109 matches for seasons 2000-2013. Aspects of each match included days-break between matches (≤7 d vs ≥8 d), location (home vs away), travel-status (travel vs no travel), and differences between opposing teams' mean age, body mass and height (expressed as quintiles). A logistic-regression version of the generalised mixed linear model estimated each effect, which was assessed with magnitude-based inference using one extra win or loss in every 10 matches as the smallest important change. For every 10 matches played, the effects were: days break, 0.1 ±0.3 (90% CL) wins; playing away, 1.5 ±0.6 losses; travelling, 0.7 ±0.6 losses; and being in the oldest, heaviest or shortest, quintile, 1.9 ±0.4, 1.3 ±0.4 and 0.4 ±0.4 wins respectively. The effects of age and body mass difference were not reduced substantially when adjusted for each other. All effects were clear, mostly at the 99% level. The effects of playing away, travel and age difference were not unexpected, but the trivial effect of days break and the advantage of a heavier team will challenge current notions about balancing training with recovery and about team selection.



Gaelic Football
#1 Duration specific Running performance in Elite Gaelic Football
Reference: J Strength Cond Res. 2017 Apr 25. doi: 10.1519/JSC.0000000000001972. [Epub ahead of print]
Authors: Malone S, Solan B, Hughes B, Collins K
Summary: The aim of the current investigation was to determine the position and duration specific running performance of elite Gaelic football players through the use of a moving average method. Global positioning system data (4-Hz, VX Sport, New-Zealand) were collected from thirty-five (n = 35) elite Gaelic football players across a two season period. A total of 32 competitive matches were analysed with 300 full match play data samples obtained for final analysis. Players were categorised based on positional groups; full-back, half-back, midfield, half- forward and full-forward. The velocity-time curve was analysed for each position using a rolling average method, where maximal values were calculated for ten different time durations (1-10 min) using total distance (m·min), high-speed (m·min) and sprint distance (m·min) across each match. There were large differences between the 1 and 2 min rolling averages and all other rolling average durations. Smaller differences were observed for rolling averages of a greater duration. Midfielders covered significantly more relative total, high speed and sprint distance than other positions across all time periods (p < 0.05; ES: 0.84-1.33), with half-backs (p < 0.05; ES: 0.74 - 1.22) and half-forwards (p < 0.05; ES: 0.99-1.45) covering more relative distance than full-backs and full-forwards. The results of the current investigation suggest that running performance within Gaelic football fluctuates across match-play. These data provide further knowledge of the running requirements of Gaelic football competition and this information can be used to aide coaches and practitioners in adequately preparing athletes for the most demanding periods of play.


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