A Comparison of Elite and Sub-elite Match-Play Running Performance of Gaelic Football Players.

ABSTRACT: Donnelly, S, Collins, K, Burns, C, O'Neill, C, and Mangan, S. A comparison of elite and sub-elite match-play running performance of Gaelic football players. J Strength Cond Res 38(5): 912-923, 2024-This research aimed to examine differences in match-play running performance between elite and sub-elite Gaelic football players. Global Positioning System devices were used to record the match-play running performance of sub-elite and elite players during the 2018 and 2019 seasons, respectively. In total, 783 samples were collected from 31 sub-elite and 30 elite players, from 1 elite and 1 sub-elite team. Comparisons were made on a team and positional level. Statistical significance was accepted at p ≤ 0.05. Significant positional differences were present between all positions with varying effect sizes (ESs) and p-values. Effect size was used to determine the magnitude of statistical difference. On a team level, the elite covered significantly more relative distance (p = 0.021, ES = 0.007) and elicited significantly higher average speed (p = 0.023, ES = 0.007) in quarters 2, 3, and 4 than the sub-elite. The elite covered significantly more relative distance high-intensity running (17-21.9 km·h-1; p = 0.002, ES = 0.012) in quarter 3 and performed significantly more power events per minute (p = 0.006, ES = 0.009) in quarter 4. In quarter 1, the sub-elite performed significantly more power events per minute (p = 0.006, ES = 0.009), relative high-speed running (≥17 km·h-1; p = 0.011, ES = 0.009), and relative distance high-intensity running (17-21.9 km·h-1; p = 0.002, ES = 0.012). Power events were defined as the estimation of the number of events that depend on anaerobic processes. The present study indicates that elite players possess superior conditioning, ability to read match-play, pacing, and anaerobic capacity. Sub-elite teams may use the present study to inform their training to potentially improve conditioning, pacing, and anaerobic capacity.

Peak Running Intensity of Elite Female Field Hockey Players During Competitive Match Play.

ABSTRACT: McGuinness, A, Passmore, D, Malone, S, and Collins, K. Peak running intensity of elite female field hockey players during competitive match play. J Strength Cond Res 36(4): 1064-1070, 2022-In recent years, backroom coaching staff have relied heavily on the global demands of competitive match-play to monitor running performance within training and match environments. Although, these figures help prepare players for the demands of match-play, they do not account for the physical and physiological stress of the most intense periods of competition. The aim of the current study was to quantify the duration and position-specific maximal running performance during match-play using a 1-10-minute moving average epoch methodology. Twenty-six (n = 26) elite international female field hockey players (23 ± 3 years; 162.6 ± 13 cm; 66 ± 6 kg) participated in the current observational study. Data were collected during 22 international games, resulting in over 360 individual samples (n = 368) being obtained for analysis. Players were categorized based on their positional lines of play (defenders, midfielders, and forwards). Variables of interest included relative total (m·min-1), high-speed (>16 km·h-1; m·min-1) and sprint distance (>20 km·h-1; m·min-1). Regardless of position, varying differences were observed between 10-minute rolling average for relative total (mod-large), high-speed (mod-large), and sprint (mod-large) distance respectively. Furthermore, as the duration of the rolling average increased, so did the observed differences (small). The forwards (119.3 ± 19.7 m·min-1) were reported to have the highest peak output during minute one for relative high-speed distance when compared with the defenders (100.7 ± 19.7, effect size [ES] 0.9, large) and the midfield (106.8 ± 23.4 m·min-1, ES 0.5, moderate). The results of the current study show that the running performance of field hockey players alters during match-play irrespective of moving average. Finally, the data will aid practitioners in the development of sport-specific drills to adequately prepare hockey players for the maximal intensity periods of elite hockey match-play.

Match-Play Running Demands and Technical Performance Among Elite Gaelic Footballers: Does Divisional Status Count?

ABSTRACT: McGahan, JH, Mangan, S, Collins, K, Burns, C, Gabbett, T, and O'Neill, C. Match-play running demands and technical performance among elite Gaelic footballers: Does divisional status count? J Strength Cond Res 35(1): 169-175, 2021-The aim of the current study was to compare positional differences in running demands and technical performance variables among elite Gaelic football teams from separate divisions. Data were obtained from a division 1 (26.7 ± 2.9 years, 179.2 ± 21.3 cm, 89.9 ± 21.2 kg) and a division 3 (25.7 ± 3.5 years, 183.0 ± 4.7 cm, 84.4 ± 6.5 kg) team. Match-play running variables were collected using 4-Hz global positioning system (GPS) units (VX Sport; Visuallex Sport, Lower Hutt, New Zealand) (Match data sets; division 1: n = 107, division 3: n = 97). Selected variables assessed were high-speed running distance (HSR) (≥17 km·h-1), number of high-speed efforts (HSE) (≥17 km·h-1), relative high-speed distance (RHSD) (≥17 km·h-1; m·min-1), and percentage of time at high speed (%HS). Each variable was analyzed across the 5 positional groups in Gaelic football (full back, half back, midfield, half forward, full forward). The same 25 competitive games were analyzed using the GPS and the Sports Code video analysis system (Sports Code Elite V9; Sportstec, Warriewood, NSW, Australia). Technical performance variables selected for analysis were total kick/hand passes, tackles, shots, and percentage of time in possession. High-speed running distance running demands were differentiated between the divisions; the division 3 team demonstrated significantly greater HSR, HSE, RHSD, and %HS than the division 1 team (p ≤ 0.05). Positional-specific analysis found that the division 3 full back and midfield positional lines had significantly greater HSR, RHSD, and %HS than their division 1 counterparts. The division 1 team made a greater number of total tackles, with significantly more tackles in the middle third (p ≤ 0.05). The division 3 team performed a significantly greater number of hand passes and unsuccessful shots per game (p < 0.01). The results of this study indicate that overall technical proficiency, rather than high-speed running profiles, differentiate division 1 and 3 Gaelic football teams.

Association between eccentric knee flexor strength and hamstring injury risk in 185 elite Gaelic football players.

Hamstring strains are the most common time-loss injury in elite Gaelic football affecting over 20% of players per season. Thus, there is a need to identify factors contributing to the onset of hamstring injuries in order to inform injury risk management strategies. The current study investigated whether eccentric knee flexor strength and between-limb imbalances were associated with increased risk of sustaining a time-loss hamstring injury in elite Gaelic football players. A total of 185 elite male players (26.9 ± 2.7 years, 86.4 ± 6.2 kg, 183.4 ± 5.6) were prospectively followed for 12 weeks from the day of testing. Injury data were provided by the team medical staff. Twenty-eight players (16%) sustained a time-loss hamstring injury following testing. Players that did not sustain a hamstring injury had greater average between-limb asymmetries (uninjured = 9.1%, 95% CI 7.8-10.1; injured = 5.1%, 95% CI 3.7-6.7; P = .001). Eccentric knee flexor strength profiles were not associated with increased or decreased risk of sustaining a hamstring injury and did not alter the post-test probability of sustaining a hamstring injury across the investigation period. These findings do not support the use of eccentric knee flexor strength metrics in managing hamstring injury risk in elite male Gaelic football players.

Cooperation of two distinct coupling proteins creates chemosensory network connections.

Although it is appreciated that bacterial chemotaxis systems rely on coupling, also called scaffold, proteins to both connect input receptors with output kinases and build interkinase connections that allow signal amplification, it is not yet clear why many systems use more than one coupling protein. We examined the distinct functions for multiple coupling proteins in the bacterial chemotaxis system of Helicobacter pylori, which requires two nonredundant coupling proteins for chemotaxis: CheW and CheV1, a hybrid of a CheW and a phosphorylatable receiver domain. We report that CheV1 and CheW have largely redundant abilities to interact with chemoreceptors and the CheA kinase, and both similarly activated CheA's kinase activity. We discovered, however, that they are not redundant for formation of the higher order chemoreceptor arrays that are known to form via CheA-CheW interactions. In support of this possibility, we found that CheW and CheV1 interact with each other and with CheA independent of the chemoreceptors. Therefore, it seems that some microbes have modified array formation to require CheW and CheV1. Our data suggest that multiple coupling proteins may be used to provide flexibility in the chemoreceptor array formation.

Cross-Sectional Investigation of Self-Reported Concussions and Reporting Behaviors in 866 Adolescent Rugby Union Players: Implications for Educational Strategies.

OBJECTIVE: To examine the self-recalled concussion and bell ringer (BR) prevalence, reporting rates, and reporting behaviors in adolescent rugby players. DESIGN: Cross-sectional survey. SETTING: School classroom. PARTICIPANTS: Adolescent male rugby players aged 12 to 18 years (n = 866). MAIN OUTCOME MEASURES: Concussion and BR prevalence, reporting rates, and reporting behaviors. RESULTS: The sample reported a concussion and BR prevalence rate of 40% and 69.9%, respectively. Of these athletes with a history, 38.4% and 86.4% suffered recurrent concussions and BRs, respectively. The total reporting rates per 1000 suspected concussions and BRs were 474.8 [95% confidence interval (CI), 415.4-534.3] and 238.7 (95% CI, 217.8-259.5), respectively. The athletes highlighted several barriers which hindered their truthful reporting of concussion, including "not thinking the injury is serious enough to report" (70%), "wanting to win the game" (38%), and "not wanting to miss future games or training" (48%). CONCLUSIONS: Educational interventions are an invaluable component within a socioecological framework aimed at improving the concussion reporting rates of adolescent athletes. The self-recalled prevalence, underreporting rates, and behaviors of the sample are alarming, which prompts the need to further explore their motivational beliefs behind their decision to underreport a potential concussion. The information obtained can be used to tailor personalized interventions for specific athlete samples.

Is It Time to Give Athletes a Voice in the Dissemination Strategies of Concussion-Related Information? Exploratory Examination of 2444 Adolescent Athletes.

OBJECTIVE: The objective of the research was to screen male and female adolescent athletes on their concussion educational histories and preferred future methods of education in terms of educational messenger, modality, and concussion-related areas of interest. DESIGN: Cross-sectional survey. SETTING: Examination setting within the classroom. PARTICIPANTS: Adolescent male (n = 1854) and female (n = 590) athletes aged 12 to 18 years. MAIN OUTCOME MEASURES: To explore the concussion educational histories and preferred future methods of education in Irish male and female adolescent athletes. RESULTS: 19.7% (n = 482) of the sample received education in the past 12 months. Male athletes had a significantly higher rate of previous education than female athletes (41% vs 17%). The methods used in previous educational interventions are failing to match the interests of the athletes. Sex played a significant role in the preferred educational methods, as male and female athletes had significant differences in their choice of educational messenger, modality, and concussion-related areas of interest. CONCLUSIONS: The current disparity in previous concussion education rates between male and female adolescent athletes should be addressed. Forthcoming research should explore the efficacy of tailoring knowledge translation strategies to match the specific needs of the recipient.

Factors that Influence Session-Rating of Perceived Exertion in Elite Gaelic Football.

Malone, S, Hughes, B, Roe, M, Mangan, S, and Collins, K. Factors that influence session-rating of perceived exertion in elite Gaelic football. J Strength Cond Res 34(4): 1176-1183, 2020-The current investigation examined the relationships between external training load (TL) measures and the session rating of perceived exertion (s-RPE) within Gaelic football players. Furthermore, we examined the effect that player experience, playing position, and 1-km time trial (TT) performance had on perception of TL. Physical performance (total distance, high-speed distance, very high-speed distance, max velocity, total accelerations, and maximal velocity exposures) and perceived TL (s-RPE) data were collected from 45 elite intercounty Gaelic football players (mean ± SD age of 24.2 ± 2.9 years; height: 180 ± 7 cm; mass: 81 ± 7 kg) over a 1-year period this resulted in 4,095 individual training session data being collected. There were moderate to very large associations between s-RPE and distance measures. Post hoc analysis revealed that the 0-1-year group had a higher s-RPE TL than the 2-3-year (d = 0.84 ± 0.33, small), 4-6-year (d = 0.91 ± 0.30, small), and 7+ year (d = 0.81 ± 0.30, small) groups. Midfielders reported higher s-RPE when compared with all positions (d = 1.21 ± 0.21, moderate). Half-backs (d = 0.81 ± 0.30, small), and half-forwards (d = 0.84 ± 0.31, small) had a higher s-RPE TL than the full-backs and full-forwards when external TL was accounted for (d = 1.21 ± 0.58, moderate). When aerobic fitness was considered, a 1.2% AU increase in s-RPE TL per 1 second increase in TT time (90% confidence limits: 1.07-2.64) when external TL was held constant was observed. The current investigation has shown moderate to very large associations between s-RPE and distance measures. When experience and fitness were considered as potential moderators of TL, it was observed that a given external TL may result in different internal responses between athletes. This potentially leaves individuals at risk of overtraining or failing to elicit positive adaptation. It is therefore vital that coaches and trainers give consideration to these mediators of s-RPE TL.

Methods of Monitoring Training Load and Their Association With Changes Across Fitness Measures in Hurling Players.

Malone, S, Hughes, B, Collins, K, and Akubat, I. Methods of monitoring training load and their association with changes across fitness measures in hurling players. J Strength Cond Res 34(1): 225-234, 2020-The aim of the current investigation was to assess the dose-response relationship for various methods of monitoring training load (TL) and changes in aerobic and anaerobic fitness in hurling players. Training and match load measures were collected from 30 hurling players (speed at different blood lactate [vLT, vOBLA], maximal oxygen uptake [VO2max], speed at VO2max [vVO2max], peak treadmill velocity [PTV] running economy [RE] Yo-Yo intermittent recovery test (Yo-YoIR1, Yo-YoIR2), speed at 5, 10 , 20 m, and repeated sprint ability [6 × 35 m]) before and after during a 12-week in-season period. Mean weekly training and match loads as determined by s-RPE, bTRIMP, luTRIMP, eTRIMP, iTRIMP, and gTRIMP were correlated with each other, percentage change in VO2max, vVO2max, RE, PTV, the speed at blood lactate concentrations of 2 mmol·L (vLT) and 4 mmol·L (vOBLA), and YoYoIR1, Yo-YoIR2 performance. iTRIMP showed a trivial association with s-RPE and a small to moderate association with other heart rate-based methods. Small to large changes (effect size: 0.38-1.12) were observed in aerobic and anaerobic fitness measures were observed across the 12-week period. Trivial to very large associations (r = 0.11-0.78) were observed between TL variables and changes in fitness depending on the variable analyzed. iTRIMP was shown to have large to very large associations with changes in vOBLA {r = 0.78 (95% confidence interval [CI]: 0.71-0.88)}, VO2max (r = 0.77 [95% CI: 0.68-0.82]), RE (r = 0.77 [95% CI: 0.67-0.82]), Yo-YoIR1 (r = 0.69 [95% CI: 0.51-0.72]), and RSAb (r = 0.66 [95% CI: 0.60-0.72]) with moderate associations reported between iTRIMP and other variables. All other measures of TL showed trivial to moderate associations (r = 0.11-0.66). The current investigation shows that fully individualized training load (iTRIMP) measures may potentially offer a better understanding of dose-response relationships when compared with subjective and nonindividualized measures of TL to changes in aerobic and anaerobic fitness in team sports athletes; as such, it may be suggested that practitioners should use individualized measures of TL assessment within their day-to-day practices.

Acceleration Profile of Elite Gaelic Football With Special Reference to Position of Play.

Ryan, M, Malone, S, Donnellan, A, and Collins, K. Acceleration profile of elite Gaelic football with special reference to position of play. J Strength Cond Res 34(6): 1750-1758, 2020-The current study aimed to characterize the positional match-play demands of elite Gaelic football players with special reference to acceleration using predetermined 5-minute periods (epochs). Thirty-five male Gaelic players (mean ± SD, age: 24 ± 6 years; height: 180 ± 7 cm; mass: 81 ± 7 kg) across 5 playing positions (full-back, half-back, midfield, half-forward, and full-forward) were monitored during the investigation. Player movement was recorded during 19 matches using 4-Hz global positioning system technology (VXSport, New Zealand) resulting in 154 player observations. Global positioning system was used to record total distance (m), (high-speed running; m; ≥17 km·h), (very high-speed running distance; m; ≥22 km·h), the number of accelerations (n), duration of accelerations (s), peak acceleration (m), and distance of accelerations (m). Acceleration profiles were position dependent with midfielders found to have a high accumulation of acceleration movements when compared with all other positions (p ≤ 0.05). Declines of -2 to -32% for acceleration distance (m) depending on positional line of play were observed during match-play. Less high-speed running and very high-speed running distance was performed by the full-back line (high-speed running; -39% and very high-speed running; -36%) and full-forward line (-35%; -29%) when compared with half-back, midfielders, and half-forwards (p = 0.01, d = 1.35-1.77). Similar trends were reported for peak acceleration distance (p = 0.01, d = 1.15-1.93). The current investigation provides a greater understanding of temporal differences in acceleration profiles of playing position. We show that half-back, midfield, and half-forwards have the highest acceleration movements; these data can assist coaches in appropriately preparing players for the required acceleration distances required during match-play.

Monitoring Wellness, Training Load, and Running Performance During a Major International Female Field Hockey Tournament.

McGuinness, McMahon, G, A, Malone, S, Kenna, D, Passmore, D, and Collins, K. Monitoring wellness, training load, and running performance during a major international female field hockey tournament. J Strength Cond Res 34(8): 2312-2320, 2020-The current observational study quantified players' activity profiles during a major international female field hockey tournament and determined whether an association exists between well-being measures and running performance within elite female hockey players. Elite female field hockey players (23 ± 3 years; 162.6 ± 13 cm; and 66 ± 6 kg) participated in the study. Participants running performance was monitored using global positioning system technology (S5; Catapult Innovations, Scoresby, Victoria, Australia), with daily well-being questionnaires used to quantify player responses during the tournament. Thresholds for the magnitude of the observed change for each variable were determined using the Hopkins Spreadsheets for analysis of controlled trials. Relative distance (m·min) was likely lower when compared with game 1 in game 7. Relative high speed (m·min >16 km·h) was likely lower in games 5, 6, and 7 when compared with game 1. Subjective load was very likely higher in game 2 and very likely lower in game 3 when compared with game 1. Mood and sleep quality were likely lower in game 1 when compared with game 4 and game 7. Muscle soreness was likely higher when compared with game 1 in game 7. During the tournament, it was observed that a decrease in players' daily well-being was accompanied by changes in running performance. Furthermore, changes to players' muscle soreness and sleep quality result in decreased players' high-speed running performance during match-play. Therefore, to prevent the observed effects, coaches should adopt strategies to enhance sleep quality and incorporate specific recovery modalities to reduce musculoskeletal soreness.

The Influence of Exercise-to-Rest Ratios on Physical and Physiological Performance During Hurling-Specific Small-Sided Games.

Malone, S, Hughes, B, and Collins, K. The influence of exercise-to-rest ratios on physical and physiological performance during hurling-specific small-sided games. J Strength Cond Res 33(1): 180-187, 2019-The current study examined the impact of different exercise-to-rest ratios on hurling-specific small-sided games (SSG). Thirty-four (n = 34) hurling players were monitored during an in-season training period. Heart rate (Polar Electro Oy, Kempele, Finland) and global positioning system technology (4-Hz; VX Sport, Lower Hutt, New Zealand) were used to analyze the physical and physiological differences between exercise-to-rest ratios across bouts of SSG. Total distance (m), high-speed distance (m) (≥17 km·h), very high-speed distance (≥22 km·h) (m), total accelerations (n), acceleration distance (m), peak velocity (km·h), and % maximum heart rate (%HRmax) were measured. Exercise-to-rest ratios of 2:1 (d = 0.65 ± 0.12; moderate), and 1:1 (d = 0.43 ± 0.12; small), resulted in significant reductions in high-speed distance, very high-speed distance, and acceleration distance. Exercise-to-rest ratios of 1:2 (d = 0.63 ± 0.21; moderate), and 1:3 (d = 1.23 ± 0.22; large), resulted in increased high-speed distance, very high-speed distance, and acceleration distance, but only after the third bout. The first bout of SSG resulted in the lowest %HRmax when compared with all other bouts (d = 0.63 ± 0.22; moderate). A significant bout-to-bout increase in %HRmax independent of exercise-to-rest ratio (d = 0.25 ± 0.04; small) was observed. Exercise-to-rest ratios of 2:1 (d = 0.65 ± 0.14; moderate), and 1:1 (d = 0.65 ± 0.24; moderate), resulted in significantly higher %HRmax during all SSG bouts; however, exercise-to-rest ratios of 1:2 (d = 0.25 ± 0.04; small), and 1:3 (d = 0.15 ± 0.04; trivial), resulted in lower %HRmax during SSG. Coaches should be aware that reducing the rest between bouts of SSGs (2:1 and 1:1 exercise-to-rest ratios) increases the physiological response (%HRmax) with reduced high-speed running performances. Coaches now have data to allow them tp best prepare for session needs with regard to specific SSG exercise-to-rest ratios.

Effect of Training Load Distribution on Aerobic Fitness Measures in Hurling Players.

Malone, S, Hughes, B, and Collins, K. Effect of training load distribution on aerobic fitness measures in hurling players. J Strength Cond Res 33(3): 825-830, 2019-The aim of the current investigation was to quantify the training intensity distribution of hurling players and their association with changes in aerobic fitness measures within hurling players. Thirty hurling players (n = 30; age 26.5 ± 3.2 years; height 178.9 ± 3.2 cm; body mass 81.5 ± 4.5 kg) were observed during the pre-championship training period (12 weeks). Aerobic fitness measures (V[Combining Dot Above]O2max), peak treadmill velocity (km·h), heart rates (HRs) at 2 and 4 mmol·L blood lactate concentrations, and Yo-Yo intermittent recovery test performance (Yo-YoIR1) were assessed before and after the training period. Training intensities were categorized using 3 individualized HR zones based on the following criteria: low intensity (≤HR 2 mmol·L), moderate intensity (between HR 2 and 4 mmol·L), and high intensity (≥HR 4 mmol·L). Analysis of 1,025 individual training sessions showed that players spent 58.1 ± 2.5%, 24.3 ± 2.9%, and 17.6 ± 1.3% of time in the low-, moderate-, and high-intensity zones, respectively. The training time spent at high intensity (Zone 3) showed moderate-to-large associations with improvements in S2 (r = 0.80; p = 0.04) and S4 (r = 0.58; p = 0.03). Similar trends were observed for time spent in high intensity and improvements in V[Combining Dot Above]O2max (r = 0.77; p = 0.001) and Yo-YoIR1 performance (r = 0.65; p = 0.05). Hurling players have been shown to spend the majority of training time in low (≤ HR 2 mmol·L) to moderate intensity (between HR 2 and 4 mmol·L) training. However, only the time spent at high intensity (≥90% of maximal HR) was related to changes in aerobic fitness. These results support the usefulness of the quantification of aerobic training load using HR. The study also supports the efficacy of spending elements of training time within the high-intensity zone to increase hurling player's aerobic fitness characteristics.

Physical Activity and Physiological Profiles of Elite International Female Field Hockey Players Across the Quarters of Competitive Match Play.

McGuinness, A, Malone, S, Hughes, B, and Collins, K. Physical activity and physiological profiles of elite international female field hockey players across the quarters of competitive match play. J Strength Cond Res 33(9): 2513-2522, 2019-The aim of the current investigation was to quantify the physical and physiological demands of elite international female field hockey across the quarters of match-play. Twenty-seven elite international female field hockey outfield players (23 ± 3 years; 162.6 ± 13.0 cm; 66.0 ± 6.0 kg) participated in the current observational study during the 2016-2017 season. Participants were monitored using global positioning system technology and HR monitors. Players were categorized based on 3 different playing positions. Activity was categorized into total distance (in meters), relative total distance (m·min), low-, moderate-, and high-intensity distance (m), maximum velocity (km·h), and percentage maximal velocity (%). Physiological demands were quantified through players peak heart rate (HRPeak), which was classified based on the player's individual HRmax determined using a Yo-Yo intermittent recovery level 1 test. Players spent on average 38 ± 8 minutes in match play. The total distance covered was 4,847 ± 583 m (127.6 ± 15.6 m·min). Defenders covered a greater total distance across all 3 positions (p = ≤ 0.05). The midfielders covered a greater moderate-intensity distance (p ≤ 0.001), whereas the forwards covered more high-intensity distance (p ≤ 0.001). The HRpeak of the players was 198 ± 4 b·min with a mean exercise intensity of 95 ± 1% HRmax. The time spent >70% HRmax decreased significantly across the quarters (p = 0.01, η = 0.03). Defenders were found to spend more time >85% HRmax when compared with other positions (p ≤ 0.001, η = 0.28). The current study provides normative data that coaches should consider when developing training drills to better optimize the positional physical and physiological activity profiles that best replicate match play.

Physical and Physiological Demands of Elite International Female Field Hockey Players During Competitive Match Play.

McGuinness, A, Malone, S, Petrakos, G, and Collins, K. The physical and physiological demands of elite international female field hockey players during competitive match play. J Strength Cond Res 33(11): 3105-3113, 2019-The aim of the current investigation was to quantify the physical and physiological demands of elite international female field hockey match play across halves of play. Thirty-eight participants (24 ± 5 years; 173 ± 5 cm; 72 ± 5 kg) took part in 19 competitive matches during the 2014-2015 season. Participants were monitored with global positioning system technology and heart rate monitors. Players were categorized based on 3 different playing positions. Activity was categorized into total (m), high-speed running distance (m; >16 km·h), and relative distance (RD) (m·min) due to the use of rolling substitutions. Heart rate was classified based on the percentage of players' individual peak heart rate (HRpeak) determined by a Yo-Yo intermittent recovery level 1 test. Players spent on average 44 ± 7 minutes in match play. The total distance (TD) covered was 5,558 ± 527 m (125 ± 23 m·min) with 589 ± 160 m (13 ± 4 m·min) completed at high speed. Defenders covered a greater TD compared with other positions of play (p ≤ 0.001). Midfield players covered a greater distance at high speed (p ≤ 0.001) with the forwards having a higher relative distance (p ≤ 0.001). The HRpeak of the players was 199 ± 1 b·min with a mean exercise intensity of 86 ± 7.8% of HRpeak. The time spent >85% HRpeak decreased significantly across the halves (p = 0.04, η = 0.09, small). Defenders were found to spend more time >85% HRpeak when compared with forwards (p ≤ 0.001). The current investigation provides normative data that coaches should consider when constructing training regimen.

Seasonal Changes in Gaelic Football Match-Play Running Performance.

Mangan, S, Ryan, M, Shovlin, A, McGahan, J, Malone, S, O'Neill, C, Burns, C, and Collins, K. Seasonal changes in Gaelic football match-play running performance. J Strength Cond Res 33(6): 1686-1692, 2019-Time of season influences performance in many team sports; however, the anomaly has not yet been examined with regards to elite Gaelic football. Global positioning systems (4 Hz; VX Sport, Lower Hutt, New Zealand) were used to monitor 5 elite Gaelic football teams over a period of 5 years (2012-2016). In total, 95 matches equated to 780 full player data sets. Running performance was characterized by total distance (m) and high-speed distance (≥17 km·h; m). High-speed distance was further categorized into 4 match quarters. Time of season was determined by month of the year. Time of season had a significant effect on total distance (p ≤ 0.001 partial η = 0.148) and high-speed distance (p ≤ 0.001 partial η = 0.105). August and September were significantly different from every other month for total distance (p ≤ 0.001) and high-speed distance (p ≤ 0.002). Month of season and match quarter had a significant interaction with high-speed distance (p ≤ 0.001 partial η = 0.106). High-speed distances run in the fourth quarter in August (478 ± 237 m) and in September (500 ± 219 m) were higher than any other quarter in any other month. This is the first study to show that time of season influences running performance in Gaelic football. The findings have major implications for training practices in Gaelic football.

Chemotaxis Allows Bacteria To Overcome Host-Generated Reactive Oxygen Species That Constrain Gland Colonization.

The epithelial layer of the gastrointestinal tract contains invaginations, called glands or crypts, which are colonized by symbiotic and pathogenic microorganisms and may function as designated niches for certain species. Factors that control gland colonization are poorly understood, but bacterial chemotaxis aids occupation of these sites. We report here that a Helicobacter pylori cytoplasmic chemoreceptor, TlpD, is required for gland colonization in the stomach. tlpD mutants demonstrate gland colonization defects characterized by a reduction in the percentage of glands colonized but not in the number of bacteria per gland. Consistent with TlpD's reported role in reactive oxygen species (ROS) avoidance, tlpD mutants showed hallmarks of exposure to high ROS. To assess the role of host-generated ROS in TlpD-dependent gland colonization, we utilized mice that lack either the ability to generate epithelial hydrogen peroxide or immune cell superoxide. tlpD gland colonization defects were rescued to wild-type H. pylori levels in both of these mutants. These results suggest that multiple types of innate immune-generated ROS production limit gland colonization and that bacteria have evolved specific mechanisms to sense and direct their motility in response to this signal and thus spread throughout tissue.

The Precompetition Macronutrient Intake of Elite Gaelic Football Players.

Competition-related dietary intake has not yet been investigated in Gaelic football. The present study examined the precompetition macronutrient intake of elite male Gaelic football players. Forty players from two teams completed a food diary on the 2 days preceding competition (Day 1 and Day 2) and on the match day prior to the match (match day). Carbohydrate intake was significantly greater on Day 2 compared with Day 1, for both absolute (295 ± 98 vs. 318 ± 77 g; p = .048; -23.6 g, 95% confidence interval [-47.3, 0.2]; Cohen's d = 0.27) and relative intake (3.4 ± 1.1 vs. 3.7 ± 1.0 g/kg; p = .027; -0.3 g/kg, 95% confidence interval [-0.6, -0.03]; Cohen's d = 0.32). The number of players in accordance with and not in accordance with the guidelines for carbohydrate intake on Day 2 was significantly different to an expected frequency distribution, χ2(1) = 32.400; p ≤ .001; φ = 0.9, with a greater number of players not meeting the guidelines (observed N = 2 vs. 38). The number of players in accordance with and not in accordance with the recommendations for carbohydrate intake on match day was significantly different to an expected frequency distribution, χ2(1) = 8.100; p = .004; φ = 0.45, with a greater number of players meeting the guidelines (observed N = 29 vs. 11). The major finding from the current investigation was that a significantly greater number of players did not meet carbohydrate intake guidelines on the day before competition. Individualized nutritional interventions are required in order to modify the current prematch dietary intake.

The Seasonal Variations in Anthropometric and Performance Characteristics of Elite Intercounty Gaelic Football Players.

Kelly, RA, and Collins, K. The seasonal variations in anthropometric and performance characteristics of elite inter county gaelic football players. J Strength Cond Res 32(12): 3475-3482, 2018-There is limited research assessing the anthropometric and performance variations in elite Gaelic football. The aim of this study was to assess the anthropometric and performance characteristics of an elite intercounty squad within a season. After ethical approval and informed consent, 26 participants were assessed at the start of preseason (November), after early in-season (January), and midseason (March). Measurements included stature, body mass, sum of 8 skinfold sites (ΣSkf8), estimated body fat percentage (bf%), squat jump (SJ) and countermovement jump (CMJ), 5-, 10-, and 20-m sprint times, upper body and lower-body strength (1 repetition maximum), and Yo-Yo intermittent recovery test 2 (Yo-Yo IR2). A multivariate analysis of variance was used to determine seasonal and positional variations. Anthropometric variations were observed with an overall increase in participants' body mass and a concomitant decrease in ΣSkf8 and bf% (-21.5%, p = 0.002, η = 0.15; -1.43%, p = 0.004, η = 0.13). Performance variations showed improvements in sprint time over 5-m (p = 0.001, η = 0.19) and 10-m (p = 0.008, η = 0.11), SJ (p = 0.013, η = 0.1), CMJ (p = 0.013, η = 0.1) height and Yo-Yo IR2 (p < 0.001, η = 0.34) noted from preseason to midseason. Significant anthropometric variations are observed between the preseason and early in-season; meanwhile, significant performance variations are observed between the preseason and midseason. Distinct positional variations are evident for both anthropometric and performance characteristics at all time points. Applied practitioners should consider these findings when implementing a seasonal training plan.

Acceleration Profile of Elite Gaelic Football Match Play.

Ryan, M, Malone, S, and Collins, K. An acceleration profile of elite Gaelic football match play. J Strength Cond Res 32(3): 812-820, 2018-The use of global positioning system (GPS) technology in Gaelic football is the primary source of quantifying game demands. The aim of this study was to quantify the acceleration profile of elite Gaelic football. Thirty-six elite male Gaelic football players (mean ± SD, age: 24 ± 6 years; height: 180 ± 7 cm; mass: 81 ± 7 kg) across 5 playing positions took part in a multiple study (n = 154 observations). Player movement was recorded during 19 (n = 19) competitive games over 2 seasons using 4-Hz GPS (VXSport, New Zealand). The average total distance (m), high-speed running distance (m; ≥17 km·h), and very high-speed running distance (m; ≥22 km·h) were recorded. In addition, the number (n), distance (m), and the duration of accelerations were quantified. Accelerations were subdivided into 14 equal parts of 5-minute epochs (E1 = 0-5 minutes, E2 = 5-10 minutes, E3 = 10-15 minutes etc). Players performed 166 ± 41 accelerations. High-speed running distance and very high-speed running distance was 1563 ± 605 and 524 ± 190 m, respectively. The mean acceleration distance was 267 ± 45 m distributed between 12 ± 5 accelerations per 5-minute epoch. The maximum acceleration epoch classified as the greatest distance covered accelerating during a predetermined 5-minute epoch was 296 ± 134 m. The PEAK epoch resulted in a significant reduction of acceleration distance covered in the period before and in the subsequent epoch. An understanding of the acceleration profile in Gaelic football can inform the prescription of appropriate training regimen.