Preseason Training Period Research Articles

Can trainability constrain physical fitness adaptations to small-sided games and high-intensity interval training in young male basketball players? a prospective cohort study.

Research on the effects of training programs involving small-sided games (SSG) versus high-intensity interval training (HIIT) has been increasing in recent years. However, there is limited understanding of how an individual's initial physical fitness level might influence the extent of adaptations achieved through these programs. This study aimed to compare the impacts of SSG and HIIT on male soccer players, while also considering the players' athleticism, categorized into lower and higher total athleticism score (TSA). A prospective cohort study was conducted over a 6-week pre-season training period, involving 43 male soccer players from regional-level teams (average age 16.5 ± 0.7years). Players were evaluated at the start and after the 6-week period. One team incorporated SSG as a core component of their aerobic-based training, while the other team used HIIT. Evaluations included a countermovement jump (CMJ) test, a 30-meter linear sprint test, and the 30-15 intermittent fitness test (30-15 IFT). TSA was calculated to assess each player's overall athleticism level (classifying them as fit and non-fit). Results revealed that non-fit players showed significantly greater CMJ improvements (mean difference: 3.0cm; p < 0.005) and VIFT improvements (mean difference: 0.682km/h; p = 0.002) in SSG compared to fit players. In the HIIT group, non-fit players also revealed greater improvements than fit players in CMJ (mean difference: 2.5cm; p < 0.005) and peak speed in sprint (mean difference: 0.706km/h; p = 0.002). No significant differences were found between groups regarding the observed improvements. In conclusion, this study suggests that the initial level of physical fitness significantly influences the magnitude of adaptations. Specifically, players with lower fitness levels appear to benefit more from training interventions. Improvements in CMJ and aerobic capacity in SSG seem to depend on players' fitness levels, and a similar trend is observed in HIIT for CMJ and peak speed. Individualizing training programs is recommended, with a focus on providing greater or different stimuli to more well-prepared players to ensure their continued development.

Effect of the Administration of Cordyceps militaris Mycelium Extract on Blood Markers for Anemia in Long-Distance Runners.

In the present study, we conducted a placebo-controlled, double-blind, parallel-group comparison trial in which an extract of Cordyceps militaris (CM) mycelium was administered to long-distance runners for 16 weeks during the pre-season training period and blood test markers for anemia were investigated. The results indicated that the change rates of serum ferritin levels were moderately increased in the CM group (n = 11) but decreased in the placebo group (n = 11) during the study period, and the levels were significantly increased in the CM group compared with those in the placebo group at 4 weeks and 8 weeks after the test food intake (p < 0.05). Moreover, the change rates of hemoglobin and hematocrit were significantly increased in the CM group compared with those in the placebo group at 8 weeks after the test food intake (p < 0.05). These observations suggest that the intake of test food containing Cordyceps militaris mycelium extract is expected to effectively maintain the hemoglobin and hematocrit levels in long-distance runners, possibly via the suppression of the decrease in iron storage, which is reflected by serum ferritin, during pre-season training. Furthermore, the levels of creatine kinase were increased above the normal range in both the placebo and CM groups at registration. Interestingly, the creatine kinase levels were significantly decreased in the CM group compared with those in the placebo group at 16 weeks after the test food intake (p < 0.05). These results suggest that Cordyceps militaris mycelium extract exhibits a protective action on the muscle damage observed in long-distance runners and may suppress muscle injury. Together, these observations suggest that Cordyceps militaris mycelium extract exhibits an improving effect on the markers for not only anemia, but also muscle injury in long-distance runners during pre-season training.

Assessing criterion and longitudinal validity of submaximal heart rate indices as measures of cardiorespiratory fitness: A preliminary study in football

ObjectivesTo evaluate the criterion and longitudinal validity of field- and laboratory-derived heart rate (HR) indices of resting and submaximal fitness tests (SMFTs) as measures of cardiorespiratory fitness. DesignObservational, repeated measures. MethodsTwenty-nine semi-professional footballers participated. Laboratory assessments took place at the start and end of a preseason training period, whereby resting, SMFT HR-derived indices, and criterion measures of cardiorespiratory fitness (running economy [RE], maximal oxygen uptake [V̇O2 max] and aerobic speed [MAS]) were collected. Throughout this training period, two field-based SMFT protocols, prescribed at different intensities, were administered weekly. Individual slopes were calculated from the analysis of within-athlete change scores. Associations between laboratory and field measures were assessed via Pearson's correlation coefficient (r) and linear regression models. ResultsRelationships between SMFT HR-derived indices from laboratory and field were very-large for exercise HR (r = 0.74 to 0.87) and moderate to very-large for HR recovery (0.43 to 0.76). Moderate to very-large inverse relationships were observed between exercise HR and HR recovery with V̇O2 max and MAS (−0.41 to −0.78), whereas resting HR showed no substantial relationships. Changes in exercise HR showed large and very-large inverse correlations with preseason changes in V̇O2 max (−0.54 to −0.60) and MAS (−0.64 to −0.83). Relationships between changes in HR recovery and maximal cardiorespiratory criterion measures were moderate to large (−0.32 to −0.63). ConclusionSMFT exercise HR is a valid proxy measure of cardiorespiratory fitness irrespective of test setting, whereas the validity of HRR remains elusive and appears to vary between exercise intensities.

Effect of a 6-Week Preseason Training Protocol on Physiological and Muscle Damage Markers in High-Level Female and Male Basketball Players.

This study aimed to investigate the effects of a 6-week preseason functional and plyometric fitness training protocol, on physiological and biochemical markers of performance and exercise-induced muscle damage, and to compare the response of these markers between high-level female and male basketball players. The sample of the study consisted of 19 professional athletes (10 male; 9 female) competing in two different teams. The examined markers were body mass, BMI, fat percentage, speed, acceleration, explosiveness, vertical jumping ability, creatine kinase (CK) and lactate dehydrogenase (LDH). The preseason training period improved speed, acceleration, explosiveness and vertical jumping ability (~1-8%) and led to significant fat percentage reductions in both groups equivalently. CK and LDH increased similarly in both groups, and the percentage increases were higher for CK compared to LDH. Further investigation and a larger sample size are required in order to determine an approach that is more capable of maximizing performance without causing any possible injuries that may be related to muscle damage.

The roles of readiness and dosage in predicting outcomes of a mindful sport performance enhancement intervention with U.S. college student-athletes

Research suggests that Mindfulness- and Acceptance-Based Interventions (MABIs) can impact sport performance and performance-relevant factors, though questions remain regarding when and for whom MABIs are effective. Specifically, inquiries into intervention engagement (i.e., dosage), potentially impacted by participant readiness, are needed. The present study utilized a non-randomized control group design with U.S. collegiate athletes to investigate MABI effects. Four teams from two universities in the Appalachian region (N = 57) engaged in Mindful Sport Performance Enhancement (MSPE) interventions during their offseason or pre-season training period. Participants were assessed on flow, psychological distress, mindfulness, emotion regulation difficulties, life satisfaction, readiness to practice mindfulness, attitudes toward sport psychology, and sport performance and enjoyment. Mindfulness dosage was measured weekly via self-report. Compared to controls, initial MSPE participants reported reductions in depressive symptoms and emotion regulation difficulties, and improvements in self-rated sport performance; at 6-week follow-up, initial MSPE participants reported significant increases in mindfulness and sport enjoyment, in addition to sustained reductions in emotion regulation difficulties. Pre-intervention readiness was not associated with changes across the intervention, though higher post-intervention readiness was associated with improvements in mindfulness, life satisfaction, and sport enjoyment. Higher post-intervention readiness was also associated with significantly more engagement (i.e., dosage), though no evidence indicated that dosage moderated the relationship between readiness and outcomes. These data suggest that post-intervention readiness may impact long-term engagement in mindfulness practice, and that pre-intervention readiness may not be an accurate indicator of engagement in or outcomes of an MABI with athletes.

Thinking About Elite Performance: The Experience and Impact of Mental Fatigue in Elite Sport Coaching

Purpose: Mental fatigue causes decreases in aspects of athletes’ performance. Elite coaches commonly undertake cognitively demanding tasks and are seemingly at similar risk of subsequent performance impairment. However, elite sport coaches’ experiences of mental fatigue, alongside other markers of psychobiological stress, have yet to be quantified. Methods: Three elite coaching and performance staff (2 women and 1 man) provided 100-mm visual analog scale ratings of mental fatigue, physical fatigue, readiness to perform, and salivary samples for later cortisol (sCort) and alpha-amylase (sAA) analysis. Data were obtained on the same morning each week across a 16-week preseason. Data were subset by individual coach for descriptive and repeated-measures correlational analyses. Results: Fluctuating mental fatigue was observed over the 16 weeks (min–max; coach 1 = 25–86 AU; coach 2 = 0–51 AU; and coach 3 = 15 − 76 AU). Elevated levels of mental fatigue were reported at multiple time points, with individual variability observed. sCort (in nanomoles per liter), sAA (in micromoles per liter), and sAA:sCort indicated that coaches experienced psychophysiological stress (min–max; coach 1 sCort = 8.42–17.31, sAA = 52.40–113.06, sAA:sCort = 3.20–12.80; coach 2 sCort = 4.20–9.70, sAA = 158.80–307.20, sAA:sCort = 21.10–61.70; and coach 3 sCort = 6.81−19.66, sAA = 86.55–495.85, sAA:sCort = 4.90–35.50). A significant inverse relationship between mental fatigue and readiness to perform (r = −.44 [−.64 to −.17], P = .002) was identified. Conclusions: Elite sport coaches report elevated instances of mental fatigue during a preseason training period. Those involved in elite sports should act to understand the presence and potential subsequent impacts of staff mental fatigue and consider management or mitigation strategies. Optimization of the cognitive performance of coaches and performance staff presents as a potential source of competitive advantage.

Reliability and validity of the 21-m shuttle-run test and its application to youth soccer players during the preseason training.

This study has two purposes: first to assess the reliability and validity of the 21-m shuttle-run test (21-m SRT) and, second, to evaluate the practicality of the 21-m SRT for youth soccer players during preseason training. Twenty-seven youth soccer players (15.9 ± 0.7 yrs., males) participated in the present study. To assess the reliability of the test, each player performed the 21-m SRT twice, on separate days. Criterion validity of the 21-m SRT was determined by examining the relationship between directly measured V3 O2max and 21-m SRT performance. To test the practicality of the 21-m SRT, three 21-m SRTs and two graded exercise tests on a treadmill were performed by each youth soccer player during preseason training. Results revealed that the 21-m SRT has high correlation coefficients (r = 0.87) between test and retest and has moderate correlation coefficients (r = 0.465) between V3 O2max and SRT performance. As V3 O2max significantly increased after the training period, SRT performance (distance and heart rate immediately after the 67th shuttle run) also positively changed during the preseason training period. The 21-m SRT has high reliability with moderate validity, and it is an effective tool for coaches to examine aerobic capacity and the efficacy of a training program for youth soccer players during the preseason training period.

The field and resistance training loads of academy rugby league players during a pre-season: Comparisons across playing positions.

Male academy rugby league players are required to undertake field and resistance training to develop the technical, tactical and physical qualities important for success in the sport. However, limited research is available exploring the training load of academy rugby league players. Therefore, the purpose of this study was to quantify the field and resistance training loads of academy rugby league players during a pre-season period and compare training loads between playing positions (i.e., forwards vs. backs). Field and resistance training load data from 28 adolescent male (age 17 ± 1 years) rugby league players were retrospectively analysed following a 13-week pre-season training period (85 total training observations; 45 field sessions and 40 resistance training sessions). Global positioning system microtechnology, and estimated repetition volume was used to quantify external training load, and session rating of perceived exertion (sRPE) was used to quantify internal training load. Positional differences (forwards n = 13 and backs n = 15) in training load were established using a linear mixed effect model. Mean weekly training frequency was 7 ± 2 with duration totaling 324 ± 137 minutes, and a mean sRPE of 1562 ± 678 arbitrary units (AU). Backs covered more high-speed distance than forwards in weeks two (p = 0.024), and 11 (p = 0.028). Compared to the forwards, backs completed more lower body resistance training volume in week one (p = 0.02), more upper body volume in week three (p< 0.001) and week 12 (p = 0.005). The findings provide novel data on the field and resistance-based training load undertaken by academy rugby league players across a pre-season period, highlighting relative uniformity between playing positions. Quantifying training load can support objective decision making for the prescription and manipulation of future training, ultimately aiming to maximise training within development pathways.

Identifying and reporting position-specific countermovement jump outcome and phase characteristics within rugby league.

The countermovement jump (CMJ) has been suggested to be an important test of neuromuscular performance for rugby league (RL) players. Identifying force platform-derived CMJ variables that may be more applicable to RL positions (e.g., forwards and backs) has yet to be fully explored in the scientific literature. The aim of this study was to identify RL position-specific CMJ force-time variables. Specifically, we aimed to compare select force-time variables from the countermovement (i.e., the combination of unweighting and braking) and propulsion phases of the CMJ between the global forwards and backs positional groups. We also aimed to compare typical (i.e., jump height) and alternative (i.e., take-off momentum) outcome CMJ variables between positional groups. Finally, we sought to visually present each individual player's CMJ performance alongside the average data to facilitate the interpretation and reporting of the CMJ performances of RL athletes. Twenty-seven forwards and twenty-seven backs who competed in the senior men's English RL Championship, performed three CMJs on a force platform at the beginning of the pre-season training period. There were no significant differences in any countermovement or propulsion phase variable between positions with just small effect sizes noted (P ≥0.09, d ≤0.46). Jump height (and so take-off velocity) was significantly greater for backs with moderate effects displayed (P = 0.03, d = 0.60). Take-off momentum (take-off velocity × body mass) was largely and significantly greater for forwards (P<0.01, d = 1.01). There was considerable overlap of individual player's body mass and CMJ outcome variables across positions, despite significant differences in the mean values attained by each positional group. The results suggest that it may be beneficial for RL practitioners to identify player-specific, or at least position-specific, variables. As a minimum, it may be worthwhile selecting CMJ force-time variables based on what is considered important to individual player's or small clusters of similar players' projected successes during RL competition.

Variations in Internal and External Training Load Measures and Neuromuscular Performance of Professional Soccer Players During a Preseason Training Period.

We described the internal and external training loads (TLs) experienced by soccer players over a 4-week preseason, examined their effects on vertical jump (VJ) performance, and investigated the relationships between different TL variables. Eighteen professional soccer players performed 17 training sessions and 1 friendly-match (FM) over the preseason. The internal TL was obtained using the session-rating of perceived exertion method. The external TL variables collected were total and high-intensity distances, body-load, and high-metabolic power distance via the GPS system. VJ performance was assessed 13 times throughout the study. Moreover, total quality recovery and delayed onset muscle soreness were assessed before every training session as a measure of recovery status. Players were divided, using a median split analysis, into two groups, according to their VJ performance (i.e., “lower” and “higher” VJ). External TL variables displayed similar variations across training sessions and were significantly interrelated (r ranging from 0.48 to 0.88). In periods where higher internal TLs were detected, impaired recovery status was noticed. Notably, the higher VJ group exhibited decreased jump performance at post-test and higher internal and external TLs across the entire preseason (compared to the lower VJ group). From our results it is suggested that professional soccer players with higher VJ performance are potentially more susceptible to concurrent training effects.

The influence of external load variables on creatine kinase change during preseason training period.

The aim of the present study was to analyse the relationships between creatine kinase (CK) concentration, an indirect marker of muscle damage, and global positioning system (GPS)-derived metrics of a continuous two-week-long preseason training period in elite football. Twenty-one elite male professional soccer players were assessed during a 14-day preseason preparatory period. CK concentrations were determined each morning, and a GPS system was used to quantify the external load. A generalized estimating equation (GEE) model was established to determine the extent to which the external load parameter explained post-training CK levels. The GEE model found that higher numbers of decelerations (χ 2 = 7.83, P = 0.005) were most strongly associated with the post-training CK level. Decelerations and accelerations accounted for 62% and 11% of the post-training CK level, respectively, and considerable interindividual variability existed in the data. The use of GPS to predict muscle damage could be of use to coaches and practitioners in prescribing recovery practices. Based on GPS data, more individualized strategies could be devised and could potentially result in better subsequent performance.

Predictors of upper respiratory tract symptom risk: Differences between elite rugby union and league players

ABSTRACT This study examined possible predictors of upper respiratory tract symptom (URTS) episodes in elite rugby union and league players (n = 51) during intensive pre-season training. Baseline saliva and blood samples were collected in the first week of pre-season training for analysis of salivary secretory immunoglobulin A (SIgA) and cytomegalovirus. Thereafter, SIgA, URTS, internal training load and self-reported wellness data were repeatedly measured throughout a 10-week pre-season training period. Univariate frailty model analysis, which included 502 observations, was performed for each rugby code for the following independent predictor variables: SIgA concentration, internal training load, total wellness, sleep quantity, sleep quality and stress. Rugby union and league players experienced a similar number of URTS episodes; however, predictors of URTS episodes differed between the codes. No biomarkers or self-reported measures significantly predicted URTS risk in rugby union players, while reductions in self-reported total wellness (HR: 0.731, p = 0.004) and sleep quality (HR: 0.345, p = 0.001) predicted increased URTS risk in rugby league players. The findings from this study highlight that factors influencing URTS risk are perhaps sport specific and this may be attributed to different sporting demands and/or different management of players by team-practitioners.

Physical fitness changes among amateur soccer players: effects of the pre-season period

Abstract Study aim: To assess changes in physical fitness of amateur soccer players after a pre-season training period and baseline fitness dependencies. Material and methods: Twenty-one amateur soccer players were assessed during the pre-season. The following physical variables were assessed before and after a two-month pre-season training period: (i) cardiorespiratory fitness, (ii) strength and power, and (iii) change of direction (COD). Results: Significant decreases were found for countermovement jump (CMJ) (p &lt; 0.001; d = 1.161), drop jump (DJ) (p = 0.014; d = 0.958), and horizontal jump (HJ) (p = 0.042; d = 0.640), while no significant changes were found for the overall variables from the beginning to the end of pre-season. Fit players revealed significant decreases for CMJ (p = 0.002; d = –2.495), DJ (p = 0.004; d = –1.760), HJ (p = 0.028; d = –1.005), COD deficit (p = 0.034; d = 1.013), and maximal aerobic speed (MAS) (p = 0.026; d = –4.053). No significant changes were found for unfit players. Conclusions: Amateur soccer coaches should consider assessing physical qualities at the beginning of pre-season and use the free-of-charge monitoring tools such as session-rate of perceived exertion (s-RPE) during the training process.

The effect of pre-season football training on hematological parameters of well-trained young male football players

Background and Study Aim. The purpose of this study was to examine the effect of metabolic stress created by 6-week football training applied in the pre-season period on circulation and hematological parameters of well-trained male football players.&#x0D; Material and Methods. Fourteen male football players who competed in the U19 category of a football team in Turkish Football Super League participated in the study voluntarily. In the study, players’ systolic - diastolic blood pressures and resting heart rates were measured and their blood samples were taken before and after the 6-week training period. Laboratory analysis was made to determine counts and concentration percentage of erythrocyte, leukocyte, and platelet sub-parameters. Wilcoxon Signed-Rank test was performed to determine the difference between pre and post measurements.&#x0D; Results. Our findings indicated that baseline mean values of lymphocyte, mean cell hemoglobin, and mean corpuscular hemoglobin concentration were significantly higher than posttest mean values. The mean of diastolic blood pressure and resting heart rate measured before the preseason training camp were lower than their posttest mean values (p &gt; .05).&#x0D; Conclusion. It is thought that the decrease in the mean values of diastolic blood pressure and resting heart rate caused by the effect of regular training during the preseason training period, while the increase in the mean values of mean cell haemoglobin and mean corpuscular haemoglobin concentration caused by the increased oxygen demand of the metabolism during the training period.&#x0D;

Effect from respiratory depression on organism functionality in pre-season training period in cycling in triathlon

Effect from respiratory depression on organism functionality in pre-season training period in cycling in triathlon

American Football Players in Preseason Training at Risk of Acute Kidney Injury Without Signs of Rhabdomyolysis.

This study was designed to identify changes in blood biomarkers that would indicate excessive muscle breakdown during the initial 10 days of preseason training in collegiate American football players and subsequently increase their risk of acute kidney injury (AKI). Prospective cohort study. Preseason, heat acclimatization period. Twenty-five Division I American football players. Clinical biomarkers for muscle damage were measured during a preseason training camp. Samples were obtained before camp and approximately 5 and 10 days into camp after completion of heat acclimatization training. Creatine kinase, myoglobin, lactate dehydrogenase, and creatinine were measured. Glomerular filtration rate (GFR) was calculated. Urine was collected at each blood draw to qualitatively identify hematuria and red blood cells. A high percentage of athletes had an asymptomatic reduction in kidney function over the 10-day period. Ten of 23 athletes did have a significant, 31.6%, mean reduction in GFR, placing each at risk of AKI according to Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease (RIFLE) classification. The plasma myoglobin for the at risk of AKI group had a mean value 8× above their baseline mean on day 5 and statistically significant mean 13× higher on day 10 than baseline. The not at risk of AKI group did not have significant differences between days 0, 5, and 10. A relatively high percentage of athletes had an asymptomatic reduction in kidney function during the intense preseason training period. 43.4% of athletes in this study had a significant 31.6% mean reduction in GFR over the 10 days. According to RIFLE classification, this placed each athlete "at risk" of AKI.

Differences in physical fitness after an 8-week preseason training among elite football players aged 17-19 years.

There may be an optimal period of time to maximize the improvement of physical fitness during adolescence. The aim of this study was to examine the magnitude of changes in physical fitness after 8 weeks of preseason training according to chronological ages after the age at peak high velocity. Thirty male young football players from an elite football team (U-16, n=10; U-17, n=10; U-18, n=10) participated in the study. The players completed an 8-week general preseason football training and participated in the pre- and posttests to measure physical fitness. The 8-week preseason training improved the power of all young players (P<0.05). The 20-m sprint performance was improved by training in U-16 and U-18 (P<0.05), but no changes were found in the U-17 group (P>0.05). Significant differences were found in the arrowhead left in U-16 and U-18 (P<0.05) after training; however, no difference was observed in U-17 (P>0.05). Coordination was enhanced further in U-16 and U-17 (P<0.05) compared with that in U-18 (P>0.05). The performance of repeated sprints and Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) were similar between pre- and posttraining in all age groups (P>0.05). Collectively, the results emphasized the importance of systematic and scientific training methods to improve the fitness levels of young football players in the preseason training period. Moreover, training to improve coordination in young football players is effective at younger ages.

Pre-season Training Loads Of Elite NCAA Division 3 Female Soccer Players: A Descriptive Study

Field-based sports training traditionally revolves around the “art of coaching”, where coaches use experience and educated guesses as a primary means of conditioning players. With the advent of GPS technology, field sports have the capability to monitor external training loads more accurately thus allowing the coaching staff to design better conditioning programs in order to match sport-specific demands seen during practices and competitions, potentially improving performance. NCAA rule limitations for Division III preseason training accentuates the need to determine the training loads of these practices. PURPOSE: The purpose of the descriptive study was to examine the external training loads of elite NCAA Division III soccer players during preseason training. METHODS: 17 NCAA female Division III soccer players (20.41±1.12 years; 64.44±6.76 kg; 166.06±4.74cm) wore a portable GPS device, operating at 10Hz and incorporated with a 100Hz triaxial accelerometer, prior to every practice (n = 8) and scrimmage (n=1) during the preseason (Aug 19 - Aug 27) in central Virginia. To start the preseason, VO2max was estimated via the YOYO test. GPS collected total distance (km), work rate (m/min), hard running (>4.5 m/s; m), zone 6 running (>6 m/s; m), top speed (km/h), and intensity during practices and scrimmages during the Division III preseason. RESULTS: Estimated VO2max was reported to be 44.90±1.90 ml·kg-1·min-1. During practices, athletes covered 4.35±2.04 km, had a work rate of 42.31±10.05 m/min, covered 157.38±143.38 m of hard running, ran 33.19±56.70m in Zone 6, had a top speed of 24.54±4.59 km/h, and had an intensity of 26.66±14.13. During the scrimmage, athletes covered 6.33±2.24 km, had a work rate of 38.13±13.72 m/min, covered 227.80±194.841 m of hard running, ran 28.47±45.17 m in Zone 6, had a top speed of 25.96±4.15 km/h, and had an intensity of 40.33±17.69. CONCLUSION: The external loads of elite Division III female soccer players were found to be similar to previously reported in-season loads of Division I and Division II athletes. The short preseason training period and high external loads present a number of concerns for Division III athletes as it pertains to preseason conditioning needs and the potential for overload injury risks.

A NECK STRENGTH TRAINING PROTOCOL IN HIGH SCHOOL FOOTBALL PLAYERS FOR CONCUSSION RISK REDUCTION

Background:Increased neck strength may be a protective factor for reducing concussions in youth athletes. However, little research exists regarding validated neck strength training methods among this demographic.Purpose:To determine whether a 7-week neck strength training period is sufficient to achieve significant gains in neck strength and size amongst high school football players. Additionally, to assess if increased neck strength influences concussion outcomes.Methods:This study enrolled 54 male high school football players, ages 14-17, in a 7-week strength training protocol in which neck exercises were incorporated into preseason strength and conditioning workouts (figure 1). Pre- and post-neck strength was assessed in four directions: forward flexion (FF), extension (EXT), right lateral flexion (RLF) and left lateral flexion (LLF). Strength was measured as maximal isometric head pressure applied into a pre-inflated sphygmomanometer cuff (figure 2). Concussion totals from the subsequent 2018 season were compared with totals from the 2017 and 2016 seasons per data obtained from the team’s athletic trainer.Results:Fifty athletes in total were analyzed; 4/54 athletes did not complete final testing due to scheduling conflicts. A two sample t-test of neck circumferences revealed a statistically significant increase of 0.37 cm from pre- to post-neck strength training (p=0.0025, figure 3). Single sample strength t-test analysis (corrected for cuff pre-inflation) demonstrated a statistically significant post-test strength increase of 19.8% (FF), 11.0% (EX), 18.8% (RLF), and 18.0% (LLF) (p<0.001, figure 3). The team suffered 4 concussions in the 2018 season, 2 of which were sustained by athletes who did not participate in preseason neck training, compared to 12 concussions in 2017 and 7 concussions in 2016 (figure 3).ConclusionThis study demonstrates that increases in neck size and strength can be achieved amongst high school athletes using easily implemented training methods during a 7-week preseason training period. The additional observation of reduced concussion outcomes is not conclusive, though these initial results are promising. Additional research is needed to investigate the potential of neck strengthening in modifying concussion risk. Funding provided by the Stanford Medical Scholars Fellowship Program Figure 1.Neck ExercisesFigure 2.Strength TestingFigure 3.Results

Development of anthropometric characteristics in professional Rugby League players: Is there too much emphasis on the pre-season period?

Rugby League is a team sport requiring players to experience large impact collisions, thus requiring high amounts of muscle mass. Many players (academy and senior) strive to increase muscle mass during the pre-season, however, quantification of changes during this period have not been thoroughly investigated. We therefore assessed changes in body-composition using Dual X-Ray Absorptiometry (DXA) in eleven academy players over three successive pre-seasons and ninety-three senior players from four different European Super League clubs prior to, and at the end of, a pre-season training period. There was no meaningful change in lean mass of the academy players during any of the pre-season periods (year 1 = 72.3 ± 7.1–73.2 ± 7.2kg; ES 0.05, year 2 = 74.4 ± 6.9–75.5 ± 6.9kg; ES 0.07, year 3 = 75.9 ± 6.7–76.8 ± 6.6kg; ES 0.06) with small changes only occurring over the three-year study period (72.3–75.9kg; ES = 0.22). Senior players showed trivial changes in all characteristics during the pre-season period (total mass = 95.1–95.0kg; ES −0.01, lean mass = 74.6–75.1kg; ES 0.07, fat mass = 13.6–12.9kg; ES −0.17, body fat percentage = 14.8–14.1%; ES −0.19). These data suggest that academy players need time to develop towards profiles congruent with senior players. Moreover, once players reach senior level, body-composition changes are trivial during the pre-season and therefore teams may need to individualise training for players striving to gain muscle mass by reducing other training loads.