Female Collegiate Soccer Players Research Articles

Eccentric Hamstring Strength Imbalance among Football and Soccer Athletes.

Hamstring strain injuries (HSI) are common among football and soccer athletes. Eccentric strength imbalance is considered a contributing factor for HSI. There is, however, a paucity of data on hamstring imbalances of soccer and American football athletes as they age and advance in skill level. High school athletes will display greater interlimb discrepancies compared with collegiate and professional athletes. In addition, soccer athletes will exhibit greater hamstring asymmetry than American football athletes. Hamstring testing was performed on soccer and American football athletes using the NordBord Hamstring Testing System (Vald Performance, Albion, Australia). Age, sex, weight, sport specialization, and sport level were recorded. Maximum hamstring forces (N), torque (N · m), and work (N · s) were measured. Hamstring imbalance (%) was calculated by dividing the absolute value of the difference in leg forces divided by their sum. One-way analysis of variance and independent sample t tests compared measurements between athlete groups. A total of 631 athletes completed measurements, including 88 high school male soccer, 25 college male soccer, 23 professional male soccer, 83 high school female soccer, 28 college female soccer, 288 high school football, and 96 college football athletes. High school soccer players displayed significantly greater imbalances for torque (P = 0.03) and work (P < 0.01) than football athletes. Imbalances for maximum force (P = 0.035), torque (P = 0.018), and work (P = 0.033) were significantly higher for male soccer athletes in high school compared with college- and professional-level athletes. Female high school soccer players had significantly higher imbalance in torque (P = 0.045) and work (P = 0.001) compared with female collegiate soccer players. Football athletes did not experience significant changes in force imbalances between skill levels. High school soccer athletes exhibit greater hamstring imbalances than football athletes. Higher levels of play in soccer, for both male and female athletes, correlate with less hamstring asymmetry.

Physiological, anthropometric and athletic performance adaptations from completing a 1-month pre-season period. A two-year longitudinal study in female collegiate soccer players.

Collegiate coaches and integrative support staff often utilize pre-season as a brief and intense training period to prepare athletes technically, tactically, and physiologically, to meet the demands of competition during a soccer season. This study sought to examine the dose-response from performing on-field soccer activities during a four-week pre-season period in female collegiate soccer players, and if the magnitude in response was associated with accumulated exercise stress. A total of twenty-seven healthy female soccer players training as part of a collegiate soccer program volunteered to participate in this two-year longitudinal study. Data collection commenced prior to the start of each pre-season period, at the beginning of August, and was completed at the beginning of September, when pre-season ended. Data collection periods were separated by a 31-day period. Indices of cardiovascular function, anthropometry, and athletic performance were examined during each data collection period. Internal and external measures of accumulated exercise stress were recorded using the Polar Team Pro® system. When comparing the beginning to the end of pre-season, significant improvements were observed in body fat (%) [24.2 ± 6.0 "vs." 23.3 ± 5.6, p = 0.001], heart rate variability (rMSSD) [51.8 ± 25.1 "vs." 67.9 ± 34.6 ms, p = 0.002], resting heart (bpm) [73.8 ± 12.1 "vs." 64.3 ± 8.8, p = 0.001] and cardiorespiratory performance (YoYo IRTL-1) [925.8 ± 272.8 "vs." 1,062.6 ± 223.3 m, p = 0.001]. Significant reductions in musculoskeletal performance were observed through vertical jump height (cm) [24.9 ± 23.7, p = 0.04]. Change in the end of pre-season body weight (kg) was significantly associated with accumulated accelerations and decelerations [r ≥ 0.49, p = 0.01]. End of pre-season change in cardiorespiratory performance was significantly associated with both accumulated training load (au) and TRIMP (au) [r ≥ 0.63, p = 0.01]. In conclusion, performing a four-week pre-season period, involving only on-field training, can promote positive and significant adaptations in anthropometry, cardiovascular function, and athletic performance measures in female collegiate soccer players. The magnitudes of these adaptations were associated with both internal and external measures of accumulated exercise stress.

Accumulated Workload Differences in Collegiate Women's Soccer: Starters versus Substitutes.

The purpose of this study was to estimate the workloads accumulated by collegiate female soccer players during a competitive season and to compare the workloads of starters and substitutes. Data from 19 college soccer players (height: 1.58 ± 0.06 m; body mass: 61.57 ± 6.88 kg) were extracted from global positioning system (GPS)/heart rate (HR) monitoring sensors to quantify workload throughout the 2019 competitive season. Total distance, distance covered in four speed zones, accelerations, and time spent in five HR zones were examined as accumulated values for training sessions, matches, and the entire season. Repeated-measures ANOVA and Student's t tests were used to determine the level of differences between starter and substitute workloads. Seasonal accumulated total distance (p < 0.001), sprints (≥19.00 km/h; p < 0.001), and high-speed distance (≥15.00 km/h; p = 0.005) were significantly greater for starters than substitutes. Accumulated training load (p = 0.08) and training load per minute played in matches (p = 0.08) did not differ between starters and substitutes. Substitutes had similar accumulated workload profiles during training sessions but differed in matches from starters. Coaches and practitioners should pursue strategies to monitor the differences in workload between starters and substitutes.

Dietary intake of macro and micronutrients correspond with sleep behaviors in collegiate female soccer players

Both macro and micronutrient intakes have an impact on sleep behaviors in athletes, notably sleep onset latency and sleep efficiency. Proper nutrient intake supports daily muscle repair and synthesis of sleep regulating compounds (e.g., serotonin and melatonin). The objective of this study was to evaluate the relationship between sleep behaviors and dietary intake in elite college female athletes. It was hypothesized that dietary carbohydrates and vitamin intake would be associated with both sleep timing and consistency. Twenty-three female Division I collegiate soccer players were evaluated for their sleep and nutritional patterns. Athletes wore an OURA ring (OURA Health, Oulu, Finland) each night for 31 days during the competitive season. During the final three days, athletes recorded their dietary intake using the Automated Self-Administered 24-hour Dietary Assessment Tool (ASA24). All athletes were exposed to the same travel schedule throughout the evaluation period, which did not differ by more than one time zone. Pearson’s R with Bonferonni Correction was used to assess the relationship between the average daily intake of various nutrients with average nightly sleep behaviors. Total Vitamin B12 ( r=-0.63), added Vitamin B12 ( r=-0.62), and Vitamin C ( r=-0.53) were negatively correlated with average bedtimes (P&lt;0.01) while added Vitamin B12 ( r=-0.61) and Vitamin C ( r=-0.50) were also negatively associated with wake times (P&lt;0.01). Greater dietary intake of kcals from carbohydrates, with respect to recommended consumption, was associated with earlier bedtimes ( r=0.41, P&lt;0.05). In conclusion, greater intake of carbohydrates and vitamins B12 and C are associated with ideal sleep behaviors. A potential mechanism accounting for this relationship could be the enhanced contribution of antioxidants and glycemic load on the synthesis of vital hormones for sleep regulation, including serotonin and melatonin. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Patellofemoral Pain, Q-Angle, and Performance in Female Chinese Collegiate Soccer Players.

Background and objective: Female sports injuries have been neglected by science, and few relevant studies have considered female subjects. Knee pain in female soccer players is more common than in male soccer players. The number of days of absence from training and competition has been shown to be higher in females than males. The reporting of knee pain is common in female soccer players, but whether knee pain is associated with morphological features is unclear. The Q-angle of the knee has been hypothesized to be a causal factor in knee pain. Asian females have shown higher levels of valgus than non-sporting Caucasian populations, but no data exist for female Chinese players. The aim of our study was to investigate whether there are associations between knee pain, the Q-angle of the lower limb, jump performance, play time, and perceived exertion in female Chinese collegiate soccer players. Materials and Methods: We measured the Q-angle, patellofemoral/anterior knee pain (SNAPPS questionnaire), and CMJ and SJ performance of 21 subjects (age: 20.09 ± 1.13 years, weight: 56.9 ± 6.26 kg, height: 164.24 ± 4.48 cm, and >10 years of practice) before and after a match; Borg scale and play time results were also recorded. Results: We found that our studied group had higher Q-angles in comparison to other ethnic groups reported in the literature, as well as an association of the Q-angle with the age, height, and weight of the players; however, contrary to other studies, we did not find any association between the Q-angle and knee pain, jumps, play time, or perceived exertion. Knee pain was not associated with any of the measured variables. Conclusions: Female Chinese soccer players showed higher Q-angles than players of other ethnic groups, a result that was associated with anthropometrics. The Q-angle was not found to be associated with knee pain, for which the sole determinant was body height.

A Comparison Between an NAIA and an NCAA Division I Women's Soccer Teams' Nutrition Knowledge, Nutrition Knowledge Sources, and Dietary Habits (HWCC)

Introduction: The nutritional needs of college athletes differ from their non-athlete counterparts. Sufficient consumption of nutrients among this population is dependent on a variety of factors, including nutrition knowledge and access to nutrition information resources. Financially, National Association of Intercollegiate Athletics (NAIA) schools are at a disadvantage compared to National Collegiate Athletic Association (NCAA) Division I schools. This may potentially give NCAA Division I athletes access to more reliable nutrition education sources, while placing NAIA college athletes at a nutritional disadvantage. Methods: This research study investigated the relationship(s) between female soccer players’ (n=16) nutrition knowledge sources, nutrition knowledge, and dietary habits. This study also assessed the differences in the nutrition knowledge and dietary habits of NCAA Division I athletes and NAIA athletes. Data was collected using an online survey. Results: Descriptive statistics indicate that nutrition knowledge was poor among all study participants. Inferential analyses indicate that there is not a significant difference in nutrition knowledge scores using division as a grouping variable (p = 0.312). Similarly, there was not a significant difference in dietary quality scores using division as a grouping variable (p = 0.336). Conclusions: The results of this study indicate that collegiate female soccer players may lack nutrition knowledge, regardless of the division in which they participate. Because of the importance of adequate nutrition in college athletes, this area would benefit from additional research.

Asymmetry In Single Leg Vertical Countermovement Hop Kinematics In Collegiate Female Soccer Players

Multidirectional sports such as soccer have a high incidence rate of anterior cruciate ligament injury. Asymmetries between limb have been linked to such non-contact injuries, thereby outlining the importance of screening measures that may identify at-risk groups. Specifically, tasks such as a vertical single leg countermovement (SLC) jump can provide an objective measure of frontal and sagittal plane asymmetries. PURPOSE: To identify lower limb asymmetries during a SLC jump. METHODS: 25 collegiate female soccer players (height: 167.4 ± 6.0 cm, mass: 67.16 ± 6.6 kg) completed 3 maximum SLC jumps on each limb. The side with the highest average jump height was defined as the high performance (HP) side and compared to the low performance side (LP). An 8 camera markerless motion capture system was utilized to analyze kinematic data at peak knee flexion during both the takeoff (TO) and landing (LN) phase using advanced machine learning. Force platforms measured the peak takeoff and landing vertical ground reaction force (GRF). A two-factor repeated measures ANOVA (p < 0.05) was used to determine differences between side (HP, LP) and phase (TO, LN) during the SLC task. RESULTS: 52% of the players had greater jump performance on their preferred kicking side. A main effect of side (p = 0.035) and phase (p < 0.001) was found for knee flexion (HP: TO 67.2 ± 7.2°, LN 60.5 ± 10.8°; LP: TO 65.0 ± 6.5°, LN 58.8 ± 7.2°). Likewise, a main effect of side (p < 0.001) and phase (p < 0.001) was found for GRF (HP: TO 1373 ± 236 N, LN 2238 ± 435 N; LP: TO 1341 ± 224 N, LN 2088 ± 280 N). A phase main effect was found for both hip flexion (p = 0.002) (HP: TO 49.8 ± 10.9°, LN 42.5 ± 11.9°; LP: TO 50.8 ± 10.1°, LN 41.0 ± 12.8°) and adduction (p = <0.001) (HP: TO 8.1 ± 4.4°, LN 5.5 ± 4.9°; LP: TO 8.7 ± 3.8°, LN 5.1 ± 5.7°). Significant main effects were not present for knee abduction (p > 0.05). CONCLUSIONS: Collegiate female soccer players demonstrate greater knee and hip flexion and hip adduction occur during the take-off phase of the single leg vertical jump compared to the landing phase. Additionally, the leg with greater performance has increased knee flexion during both take-off and landing which corresponds to greater peak force. These identified asymmetries between phase and limb could be considered important factors in monitoring potentially at-risk populations.

Associations Between Fitness Components In Collegiate Female Soccer Players

Associations Between Fitness Components In Collegiate Female Soccer Players

Competition Stress Prolongs Exercise Recovery In Collegiate Soccer Players

Athlete conditioning is vital to success in collegiate soccer. Effective conditioning programs incorporate adequate rest between exercise sessions. The duration of an athlete's recovery may be sensitive to variables beyond training load, including emotional and psychological factors. PURPOSE: To determine the effect of competition stress on recovery time in female collegiate soccer players. METHODS: We monitored 30 Division 1 female soccer players for 35 consecutive days. All athletes wore Polar Team Pro devices (Polar Electro Inc., Bethpage, NY), which recorded duration of exercise, total distance covered, kcals burned, number of sprints performed, average and maximum speed achieved, average and maximum heart rate (HR), and Polar calculations of training load, cardio load, and recovery duration in hours. Data were captured for 20 practices and 7 games, resulting in 858 observations. Linear regression tested the effect of formal competition on recovery duration holding constant time of day and all significant workload variables. RESULTS: Players were 20.1 ± 1.1 years of age. Across all practice and competition sessions, the mean duration of exercise was 59.0 ± 38.8 min, total distance covered was 2,518.9 ± 2,074.5 m, and estimated energy consumption was 381.7 ± 284.8 kcals. Athletes performed 5.9 ± 7.9 sprints per session, maintained an average speed of 2.8 ± 1.2 km/h, and achieved a maximum speed of 20.7 ± 7.3 km/h. Average HR was 131.9 ± 24.3 bpm, maximum HR was 177.4 ± 32.7 bpm, training load was 70.1 ± 59.3, and cardio load was 76.0 ± 62.2. Recovery duration was 12.8 ± 15.7 hr following practice sessions and 51.3 ± 59.6 hr following competitions (p < 0.001). Holding constant all significant predictors (time of day, exercise duration, total distance covered, estimated kcals, number of sprints, average speed, average HR, training load, and cardio load), formal competition corresponded to 33.8 additional hours of recovery (p < 0.001; 95% CI of β = 27.7 to 39.9; model r2 = 0.691; adjusted r2 = 0.687). CONCLUSION: Sufficient recovery is a crucial component of optimal performance in collegiate athletics. Our data indicate prolonged recovery duration following formal competition settings, which could not be explained by workload. Further research on psychological contribution to allostatic load is warranted.

Pre-season Training And Its Effect On Altering Cardiovascular Function, Anthropometry And Performance In Female Collegiate Soccer Players

Pre-season Training And Its Effect On Altering Cardiovascular Function, Anthropometry And Performance In Female Collegiate Soccer Players

Examining Indices Of Athletic Performance That Can Enhance Pre-season Workload In Female Collegiate Soccer Players

Examining Indices Of Athletic Performance That Can Enhance Pre-season Workload In Female Collegiate Soccer Players

Heart Rate Variability And Its Association With The Autonomic Response During Jump Performance In Female Soccer Players

Heart rate variability (HRV) has been established as a valid index for examining cardiac autonomic modulation. The eccentric utilization ratio (EUR) is a novel index examining the stretch shortening cycle and is calculated by dividing the jump height of both the squat jump and counter movement jump. The reactive strength index (RSI) is another assessment examining the autonomic response of a muscle contraction when performing a drop jump test. Currently, there remains a paucity of inquiry around the association between heightened cardiac vagal modulation and improvement in jump performance when utilizing the stretch shortening cycle. PURPOSE: To examine the association between cardiac vagal modulation using rMSSD and jump performance assessments utilizing the stretch shortening cycle in healthy female collegiate soccer players. METHODS: Seventeen healthy female collegiate soccer players with an age of (mean ± SD) 18.5 ± 0.75 yr, a weight of 57.3 ± 9.2 kg, a height of 165.4 ± 7.2 cm, and a body fat % of 23.2 ± 7.4 volunteered as participants. HRV was analyzed in the supine position after a 10-min stabilization period. R-R intervals were recorded over 60-seconds using the Polar Team Pro® chest strap and were exported into Kubios HRV 3.4 (University of Kuopio, Kuopio, Finland) for HRV analyses. Each participant performed three separate squat jumps, counter movement jumps and drop jumps with their hands placed on their hips. Jump performance was assessed using a force plate (Hawkin Dynamics Force Plate, ME, USA). The highest jump was included for each analysis. Normality of each data set was examined using a Shapiro-Wilk’s test for normality (p > 0.05). Linear regression (R2) was utilized to examine the association between rMSSD and both EUR and RSI. This study was approved by and followed the recommendation of the Research Ethics Review board at Langara College. RESULTS: No significant associations were observed between rMSSD and both EUR (R2 = 0.004, p = 0.74) and RSI (R2 = 0.001, p = 0.87). CONCLUSION: HRV may not be suitable for examining the autonomic response when utilizing the stretch shortening cycle during jump performance testing. This investigation was funded by the Langara College ARC-1 grant.

Reliability and Validity of the 30–15 Intermittent Field Test With and Without a Soccer Ball

ABSTRACTObjective: The purpose of this study was to examine the reliability and validity of the 30–15 Intermittent Field Test (30–15IFT) with and without a ball. Methods: Twenty-four collegiate female soccer players (19.46 ± 1.22 years; 167.01 ± 7.23 cm; 60.95 ± 7.84 kg) performed 1 trial of the Yo-Yo Intermittent Recovery (YYIR) test, 3 trials of the 30–15IFT, and 3 trials of the 30–15IFT with a ball (30–15IFT-B), separated by a minimum 48 hours. Maximal intermittent running velocity (VIFT), heart rate at exhaustion (HRpeak), and rating of perceived exertion (RPE) were collected. Results: Intraclass correlation coefficients (ICCs) between trials demonstrated good reliability during the 30–15IFT in VIFT (ICC = 0.88) and HRpeak (ICC = 0.89), in addition to the 30–15IFT-B VIFT (ICC = 0.83) and HRpeak (ICC = 0.87). VIFT was significantly reduced in 30–15IFT-B (15.82 km h−1) compared to 30–15IFT (17.52 km h−1; p < .001), regardless of trial. HR and RPE were significantly greater in 30–15IFT compared to 30–15IFT-B (p < .05). Estimated maximal oxygen consumption (VO2max) YYIR and estimated VO2max of 30–15IFT and 30–15IFT-B was very strongly (r = 0.82) and strongly (r = 0.68) correlated. Conclusion: The 30–15IFT is considered valid and reliable and the 30–15IFT-B was reliable in female soccer players.

Effectiveness of daily subjective wellness measurements via mobile applications in predicting perceived exertion and training load

This study aimed to examine the effectiveness of presession subjective wellness, measured by a mobile application, in predicting the rating of perceived exertion (RPE) and training load for collegiate female soccer players throughout all training sessions of a competitive season. Thirty-three training sessions over 10 weeks involving 23 subjects were analyzed. Before each training session, players self-reported wellness measurements (sleep quality, stress, mood, soreness, fatigue, and sleep duration) through a mobile application questionnaire. Training load (active time, distance, GPS session load, and sprint score) was measured by GPS. RPE was self-reported immediately after training sessions. Generalized estimating equations found that presession wellness scores had a significant effect on postsession RPE. A 1 point increase in the wellness score corresponded with a significant increase in RPE ([Formula: see text] = 0.4[Formula: see text], 95% CI (0.05–0.91), p = 0.029). Wellness component of mood had a significant effect on RPE as noted by a 1 SD increase that corresponded to an increase in RPE ([Formula: see text] = 0.[Formula: see text], 95% CI (0.07–0.30), p = 0.001). Psychosocial component of wellness (mood) played the most influential role in predicting RPE. The results suggest that monitoring student-athlete wellness may be helpful in regulating player internal load, and increasing player mood may also lower internal load.

Header biomechanics in youth and collegiate female soccer

Concerns about the effects of intentional heading in soccer have led to regulatory restrictions on headers for youth players. However, there is limited data describing how header exposure varies across age levels, and few studies have attempted to compare head impact exposure across different levels of play with the same sensor. Additionally, little is known about the biomechanical response of the brain to header impacts. The objective of this study was to evaluate head kinematics and the resulting tissue-level brain strain associated with intentional headers among youth and collegiate female soccer players. Six youth and 13 collegiate participants were instrumented with custom mouthpiece-based sensors measuring six-degree-of-freedom head kinematics of headers during practices and games. Kinematics of film-verified headers were used to drive impact simulations with a detailed brain finite element model to estimate tissue-level strain. Linear and rotational head kinematics and strain metrics, specifically 95th percentile maximum principal strain (ε1,95) and the area under the cumulative strain damage measure curve (VSM1), were compared across levels of play (i.e., youth vs. collegiate) while adjusting for session type and ball delivery method. A total of 483 headers (n = 227 youth, n = 256 collegiate) were analyzed. Level of play was significantly associated with linear acceleration, rotational acceleration, rotational velocity, ε1,95, and VSM1. Headers performed by collegiate players had significantly greater mean head kinematics and strain metrics compared to those performed by youth players (all p < .001). Targeted interventions aiming to reduce head impact magnitude in soccer should consider factors associated with the level of play.

Match Acceleration and Deceleration Patterns in Female Collegiate Soccer Players

The purpose of the current investigation was to report acceleration and deceleration match data in female collegiate soccer players and compare between positions and game halves. A total of 24 players (11 defenders, five midfielders, and eight forwards) (age: M = 19.1, SD = 1.2 years; height: M = 1.64, SD = 0.05 m; and mass: M = 62.2, SD = 5.8 kg) underwent global positioning system monitoring and performance testing. Forwards covered significantly more distance per minute during high-intensity running (effect size [d]: 0.49) and sprinting (d = 0.64) when compared to midfielders across 16 matches for players logging 22.5 min per half. Significant and meaningful positional differences were determined with forwards covering the greatest average distance per acceleration efforts (d = 0.55) and initiating acceleration and deceleration efforts from a greater initial speed (ds = 0.57 and 0.69). When analyzing across all matches for players logging ≥ 40 min per half, second half decreases occurred in the number of accelerations (p &lt; .001; d = 1.98) and decelerations (p &lt; .001; d = 1.92), average distance of accelerations (p &lt; .001; d = 0.83) and decelerations (p = .03; d = 1.30), and starting speed of accelerations (p = .01; d = 0.92) and decelerations (p = .04; d = 1.28). These results provide useful context when interpreting global positioning system–derived player-tracking metrics and can improve positional-specific training programs.

Comparison of women’s collegiate soccer header kinematics by play state, intent, and outcome

Although most head impacts in soccer are headers, limited knowledge exists about how header magnitude varies by on-field scenario. This study aimed to compare head kinematics during on-field headers by play state (i.e., corner kick, goal kick, free kick, throw-in, drill, or live ball), intent (i.e., pass, shot, or clearance), and outcome (i.e., successful or unsuccessful). Fifteen female collegiate soccer players were instrumented with mouthpiece-based head impact sensors during 72 practices and 24 games. A total of 336 headers were verified and contextualized via film review. Play state was associated with peak linear acceleration, rotational acceleration, and rotational velocity (all p < .001) while outcome was associated with peak linear acceleration (p < .010). Header intent was not significantly associated with any kinematic metric. Headers during corner kicks (22.9 g, 2189.3 rad/s2, 9.87 rad/s), goal kicks (24.3 g, 2658.9 rad/s2, 10.1 rad/s), free kicks (18.0 g, 1843.3 rad/s2, 8.43 rad/s), and live balls (18.8 g, 1769.7 rad/s2, 8.09 rad/s) each had significantly greater mean peak linear acceleration (all p < .050), rotational acceleration (all p < .001), and rotational velocity (all p < .001) than headers during drills (13.0 g, 982.4 rad/s2, 5.28 rad/s). Headers during goal kicks also had a significantly greater mean rotational acceleration compared to headers during live ball scenarios (p < .050). Successful headers (18.3 g) had a greater mean peak linear acceleration compared to unsuccessful headers (13.8 g; p < .010). Results may help inform efforts to reduce head impact exposure in soccer.

Biomechanical Changes During a 90º Cut in Collegiate Female Soccer Players With Participation in the 11.

BackgroundValgus collapse and high knee abduction moments have been identified as biomechanical risk factors for ACL injury. It is unknown if participation in the 11+, a previously established, dynamic warm-up that emphasizes biomechanical technique and reduces ACL injury rates, reduces components of valgus collapse during a 90º cut.Hypothesis/PurposeTo determine whether participation in the 11+ during a single soccer season reduced peak knee abduction moment and components of valgus collapse during a 90º cut in collegiate female soccer players.Study DesignProspective cohort studyMethodsForty-six participants completed preseason and postseason motion analysis of a 90º cut. During the season, 31 players completed the 11+ and 15 players completed their typical warm-up (control group). Peak knee abduction moment, components of valgus collapse (hip adduction, internal rotation, and knee abduction angles), and a novel measure of knee valgus collapse were analyzed with repeated-measures ANOVAs to determine differences between preseason and postseason. Smallest detectable change (SDC) and minimal important difference (MID) values were applied to contextualize results.ResultsThere was a significant main effect of time for non-dominant knee valgus collapse (p=0.03), but decreases in non-dominant knee valgus collapse only exceeded the SDC in the intervention team.ConclusionsClinically meaningful decreases in knee valgus collapse may indicate a beneficial biomechanical effect of the 11+. Participation in the 11+ may lower ACL injury risk by reducing valgus collapse during a 90º cut.Level of Evidence2b

Evaluating the effects of oral contraceptive use on biomarkers and body composition during a competitive season in collegiate female soccer players.

High training demands throughout the competitive season in female collegiate soccer players have been shown to induce changes in biomarkers indicative of stress, inflammation, and reproduction, which may be exacerbated in athletes using oral contraceptives (OCs). This study aimed to compare biomarkers and body composition between OC-using and nonusing (CON) female soccer players throughout a competitive season. Female collegiate soccer players were stratified into two groups based on their reported OC use at the start of preseason (OC: n = 6; CON: n = 17). Before the start of preseason and immediately postseason, athletes underwent a battery of performance tests. Blood draws and body composition assessments were performed before preseason, on wks 2, 4, 8, and 12 of the season, and postseason. Area-under-the-curve ratios (OCAUC:CONAUC) indicated the OC group were exposed to substantially higher levels of sex hormone-binding globulin (AUCratio=1.4, probability=P > 0.999), total cortisol (1.7; P > 0.999), C-reactive protein (5.2; P > 0.999), leptin (1.4; P = 0.990), growth hormone (1.5; P = 0.97), but substantively lower amounts of estradiol (0.36; P < 0.001), progesterone (0.48; P = 0.008), free testosterone (0.58; P < 0.001), follicle-stimulating hormone (0.67; P < 0.001), and creatine kinase (0.33, P < 0.001) compared with the CON across the season. Both groups increased fat free mass over the season, but CON experienced a greater magnitude of increase along with decreased body fat percentage. Although similar training loads were observed between groups over the season, the elevated exposure to stress, inflammatory, and metabolic biomarkers over the competitive season in OC users may have implications on body composition, training adaptations, and recovery in female athletes.NEW & NOTEWORTHY This study highlights the influence of OC use on physiological changes that occur over a 4-mo intense, competitive season and the differential systemic exposure to biomarkers, specifically those of inflammation, stress, anabolism, and energy balance, between OC-using and nonusing soccer players. Additionally, this study provides insight into changes in body composition with prolonged training between female athletes with and without OC use.

Acute Effects of Match-Play on Neuromuscular and Subjective Recovery and Stress State in Division I Collegiate Female Soccer Players.

Ishida, A, Bazyler, CD, Sayers, AL, Mizuguchi, S, and Gentles, JA. Acute effects of match-play on neuromuscular and subjective recovery and stress state in Division I collegiate female soccer players. J Strength Cond Res 35(4): 976-982, 2021-The purpose of this study was to investigate acute effects of match-play on neuromuscular performance and subjective recovery and stress state and the relationship between training load (TL) and changes in neuromuscular performance in female soccer players. Twelve National Collegiate Athlete Association Division I players participated (20.7 ± 2.3 years; 64.4 ± 7.2 kg; 164.5 ± 6.0 cm) and completed countermovement jump (CMJ) at 0 kg (CMJ0) and 20 kg (CMJ20) and the Short Recovery Stress Scale (SRSS) at 3 hours pre-match (Pre), 12 hours post-match (Post12), and 38 hours post-match (Post38). Countermovement jump variables included body mass, jump height (JH), modified reactive strength index (RSI), peak force (PF), relative PF, eccentric impulse, concentric impulse (CI), peak power (PP), relative PP (RPP), eccentric average PP, and concentric average power (CAP). The SRSS consists of 4 Stress Scales (SSs) and 4 Recovery Scales (RSs). Training loads included total distance, total PlayerLoad, high-speed running, and session ratings of perceived exertion. Significant moderate to large decreases were observed from Pre to Post12 in JH, RSI, CI, PP, RPP, and CAP in CMJ0 and CMJ20 (p < 0.05, effect size [ES] = 0.63-1.35). Significant changes were observed from Pre to Post12 in all RSs (p < 0.05, ES = 0.65-0.79) and 3 SSs (p < 0.05, ES = 0.71-0.77). Significant correlations were observed between CMJ20 PP from Pre to Post12 and all TLs (p < 0.05, r = -0.58 to -0.68). CMJ0 and CMJ20 JH and PP may indicate acute neuromuscular changes after match-play. The magnitude of CMJ20 PP decrements from Pre to Post12 may be affected by soccer match-play volumes.