Introduction: Running is one of the most popular forms of physical activity in the world providing many health benefits but also leads to an increase in overuse and tendinopathy injuries. Lower body positive pressure treadmills (LBPPT) reduce body-weight (BW) impact, benefiting individuals with musculoskeletal conditions or undergoing rehabilitation. Previous research indicates LBPPT could be a potential training alternative or reintroducing exercise sooner in rehabilitation process. The purpose of this study was to examine average impact force and accumulated impact force over the course of a 5-km run at 60% of VO2peak at various % BW to examine if there is a potential alternative to over-ground running. Methods: In total, 20 aerobically fit individuals completed a VO2peak and 5 counterbalance trials at 100% BW on a regular treadmill and 100%, 90%, 80% and 70% BW on a LBPPT. A linear mixed-effect model was used for all insole data and repeated-measures analysis of variance (ANOVA) tests of within-subject’s effects was performed for each variable. Results: The results showed a significant difference in the time it took to run the 5-km as the BW decreased (100% RT: 33.8 ± 1.1 min; 100% LBPPT: 31.8 ± 0.9 min; 90%: 30.3 ± 1.0 min; 80%: 28.0 ± 1.0 min; 70%: 24.6 ± 0.7 min; p < 0.05). Average impact force per step did not differ between conditions (p > 0.05), but the accumulated impact over the course the 5-km did significantly decrease as BW decreased (100% RT: 8283.5 ± 342.7 kN; 100% LBPPT: 8203.8 ± 326.2 kN; 90%: 6953.9 ± 348.6 kN vs. 80%: 6953.9 ± 270.0 kN; p < 0.001). Conclusions: In conclusion, the LBPPT treadmill provides a possible alternative to runners to maintain the same aerobic intensity while accumulating less force and stress on the lower extremity over a fixed distance.

BACKGROUND:Military medical readiness plays a significant role in global military operations. While the severity of combat-related trauma is evident, musculoskeletal injuries (MSK's), are the largest medical threat to deployment readiness, and accounted for more than 60% of limited duty days in 2019. Across MSK's, the spine (lumbosacral: 30%; cervical: 22%; thoracic: 10%) accounts for 62% of MSKs. In the military population, there is a tremendous economic impact in training, retaining, and deploying a service member. Return-to-duty (RTD) rates and length of time for the treatment protocols for spine surgery vary significantly in published research. Research suggests RTD rates between 3-17 months following elective traditional open lumbar and cervical spine surgery, with a RTD rate of 64% within 1 year. When examining minimally invasive lumbar spine surgery (MIS), 100% of military personal had a RTD within 3 months. Research has yet to examine the impact of MIS of the cervical spine on the RTD rates of active-duty military. METHODS:The current study retrospectively examined surgical outcomes, return to duty, and patient-centric outcomes among 156 active duty or reserve military patients who underwent an outpatient minimally invasive (n = 79) cervical spine surgery or an open (n = 77) (Laminotomy/Foraminotomy/Decompression) for the treatment of cervical spinal stenosis. RESULTS:Significant reductions in visual analog scale of 3.31 and neck disability index of 16.01 were observed from preoperative to postoperative time points. 77% of service members RTD in less than 1 month, 19% RTD in 1-2 months and 4% RTD between 2-3 months. There were insignificant differences reported in the open surgery group. DISCUSSIONS:MIS has been shown to reduce tissue trauma and patient complications. MIS procedures have resulted in reducing postoperative stress responses and improving the recovery process following surgery. In the active-duty military population this plays an important role in return to duty quickness. Our findings suggest that MIS procedures in an ambulatory surgery center on the cervical spine result in improved patient outcomes and reduced RTD time in active-duty military personnel.

Lower body positive pressure treadmills (LBPPT) have gained increasing attention due to their potential applications in sports training, rehabilitation, and biomechanics research. However, there is limited understanding of how differing body weight percentages influence gait and force production. This study aimed to investigate the relationship between force and gait parameters at different body weight percentages on a LBPPT. Twenty-seven healthy participants completed a series of walking, jogging, and running trials at three different body weight conditions: 100%, 90%, and 75%. Gait parameters, including cadence, stride length, stance time, and ground reaction force, were measured using the Digitsole Pro foot insoles and analyzed across the different conditions. Repeated measures ANOVA and pairwise comparisons were used to examine the effects of body weight percentage on the gait parameters. The results showed significant effects of BW on cadence, stride length, stance time, and impact force during running condition (p < 0.001). Jogging condition was significantly different across all % BW for all variables except ground reaction force (GRF). For walking, the only significant differences presented were for stride length on the right limb between 100% and 90% BW (p = 0.004) and 100% and 75% BW (p = 0.04) and time in stance on the left and right (p < 0.05). Pairwise comparisons revealed significant differences between the 100%, 90%, and 75% BW conditions for most gait parameters during jogging and running. These findings suggest that lower body weight percentages substantially influence gait mechanics and force production, especially as speed increases.

Injuries in soccer athletes continues to rise and there is a cause for concern. Collegiate athletes have physically demanding workloads and struggle to sleep an adequate amount each night. A potential association is how sleep could play a role in an athletes’ injury. 24 NCAA DI women’s soccer athletes were utilized during the Fall 2019 season. Athletes self-reported their daily hours slept and the athletic trainer tracked and classified athletes’ injury and illness status: no-injury, medical attention injury, or time loss injury. K-mean clustering was utilized to classify the athletes into 3 groups: injury/illness-free group (n=12), mild-to-moderate injury/illness group (n=7), and heavy injury/illness group (n=5). Sleep was statistically significantly lower in the heavy-injury group than other groups and small effect sizes were detected (d31 = .282, p < .001; d32 = .278, p < .001). Based on the data, it appears hours slept plays a factor in female soccer athletes’ risk of injury.

Introduction: The purpose of this study was to measure the nutrition knowledge of Army ROTC cadets before and after the implementation of nutrition education sessions presented by a registered dietitian nutritionist (RDN), while observing the effectiveness of nutrition intervention on this population.Methods: Army ROTC cadets (n=33; 19+1 years old) from a southeastern university participated in a 9-week study in which they completed a nutrition knowledge survey pre- and post- implementation of six nutrition education sessions. General nutrition knowledge (GNK) and sports nutrition knowledge (SNK) were measured via the Abridged Nutrition for Sport Knowledge Questionnaire (ANSKQ).Results: General, sports, and total nutrition knowledge (TNK) improved significantly between pre-survey and post-survey scores (p < .001; p < .01; p < .001, respectively). Independent samples t-test showed large t-score values (GNK t = -3.559; SNK t = -2.794; TNK t = -3.776), indicating a strong difference between the three groups. Army ROTC cadet ANSKQ scores significantly improved GNK from adequate to good, SNK from poor to adequate, and TNK from poor to adequate.Conclusions: The results of this study indicate nutrition knowledge is poor in ROTC cadets, but may improve from nutrition education interventions presented by an RDN.

Introduction: The purpose of this study was to assess the repeated measures correlations between the sums of training load (TL) variables preceding matchday and matchday countermovement jump (CMJ) height in NCAA Division I (DI) women’s soccer athletes. Methods: A total of 23 female soccer players (20 ± 1.2 years; 1.69 ± 0.06 m) participated in this study. Repeated measures correlations were used to determine the relationships between matchday CMJ height and TL variables. Results: Matchday CMJ height showed very weak to weak negative relationships with the sums of the TL variables for the microcycle preceding the match: sRPE-TL (r = -0.184, p = 0.036), TD (r = -0.229, p = 0.008), TLS (r = -0.192, p = 0.028), HSD (r = -0.229, p = 0.008), ML (r = -0.204, p = 0.020), and number of sprints (r = -0.237, p = 0.006). Conclusions: Although significant negative weak relationships were observed, the results suggest that the sums of TL variables preceding matchday may not be the most reliable indicators of matchday preparedness in collegiate DI women’s soccer. Future research should aim to investigate other strategies to predict matchday readiness in collegiate women’s soccer.

Introduction: Three-dimensional motion object tracking (3D-MOT) is perceptual-cognitive tool which utilizes executive function to train athletes to ignore distractors and enhance processing speed and peripheral focus. The benefits of perceptual-cognitive training in professional level athletes have recently been investigated in multiple sports such as basketball, soccer, and archery, but conclusive evidence suggesting test transferability of 3D-MOT training is lacking. The purpose of this research was to examine the transferability of perceptual-cognitive training to on-field soccer performance parameters. Methods: NCAA Division I women’s soccer players (n=22) between the ages of 18-25 participated in the study. NeuroTracker, a 3D-MOT device to train athletes executive function and decision making, was utilized to test the athletes. After baseline testing for both groups to determine visual tracking speed (VTS), the experimental group completed 10 3D-MOT training sessions with NeuroTracker over four-weeks. Game performance data, successful action, passing percentage, and short-medium range passing percentage, was collected utilizing Wyscout video analysis software during the 2021 season. Results: The mean VTS for the NeuroTracker training group significantly increased by 0.68 from pre-3D-MOT training to post-3D-MOT training (p<0.001) while the control group increased by 0.12 (p = 0.034). Analysis utilized an ANCOVA and observed no statistical significance for passing accuracy, successful action and short-medium passing accuracy (p > 0.05). However, the average in game passing-accuracy for the experimental group increased over the control group. Conclusions: The effect of test transferability of 3D-MOT training on soccer specific parameters may be present, but causation of test transferability is not present within the current study. Further research is needed to investigate the cause-and-effect relationship of 3D-MOT training on soccer specific parameters while utilizing recruitment of multiple teams to increase sample sizes for similar investigations.

PURPOSE: Training load quantification and monitoring is used in collegiate athletics to help coaches and supporting staff to determine whether players are prepared for upcoming matches. The purpose of this study was to assess the within-subjects correlation of matchday countermovement jump (CMJ) height and the 7-day sum of training load variables preceding matchday in NCAA Division I women’s soccer athletes. The authors hypothesized that matchday CMJ height would show negative moderate correlations with the 7-day sum of training load variables. METHODS: A total of 23 female soccer players (20 ± 1.1 years; 1.70 ± 0.07 m; 64.6 ± 7.0 kg) participated in this study. Data from seven matches from the 2020 season were included in this analysis. Repeated measures correlations (rmcorr) were used to determine the within-subjects correlations of matchday CMJ height and total distance covered (TD), training load score (TLS; using training impulse [TRIMP] calculations), number of sprints, and distanced covered at high-speed (< 9.32 mph; HODO). Alpha was set a priori at p ≤ 0.05 and the data was analyzed using R Studio (version 1.4.1106, R Studio, Boston, MA, USA) executing R (version 4.0.4, University of California, Berkeley, CA, USA). RESULTS: The correlations between training load variables and matchday CMJ height were not statistically significant (p > 0.05). The matchday CMJ height showed very weak nonsignificant relationships with TD (r = -0.071, p = 0.450, 95% CI = -0.254, 0.116), TLS (r = -0.016, p = 0.874, 95% CI = -0.191, 0.223), number of sprints (r = -0.116, p = 0.218, 95% CI = -0.296, 0.071), and HODO (r = -0.011, p = 0.904, 95% CI = -0.175, 0.197). CONCLUSIONS: The results suggest that the CMJ height may not be a good indicator of matchday preparedness in collegiate Division I women’s soccer as it did not correlate with the 7-day sum of training load variables preceding matchday. Future research should aim to address other strategies to assess matchday preparedness in collegiate women’s soccer in order to enhance training periodization to better prepare the athletes for competition.

BACKGROUND: Visual training has previously been shown to correlate to sport specific level of training and sport specific performance measures in controlled conditions. However, it remains unclear if these relationships exist between 3D-MOT training and in competition decision making metrics over the duration of a soccer season. The purpose of this study was to investigate the relationship between the effects of 4-weeks of 3D-MOT training on in-game soccer performance measures. METHODS: 25 NCAA Division I soccer players were split into two groups, after exclusionary criteria (played >10 minutes per game) only 13 were utilized for analysis NT (n = 6) and CON (n = 7). Participants completed a baseline assessment of visual tracking speed (VTS) and subsequently 10 training sessions composed of 20 trials each were performed by the Neurotracker (NT) group over a 4-week period on a 3D-MOT software Neurotracker (NT; CogniSens Athletic, Inc., Montreal, Quebec, Canada). The soccer performance metrics were obtained from WyScout where 2 game averages were examined to represent pre-NT and post-NT (Wyscout, Chiavari, Italy). An analysis of covariance (ANCOVA) was utilized to compare NT and CON mean differences among variables. RESULTS: There was a no significant difference between the CON group (53.96 ± 9.55%) and NT group (58.38 ± 11.98%) successful actions post-NT (p = 0.453, η = 0.057). There was a no significant difference between CON group (64.79 ± 9.97%) and NT group (71.71 ± 12.35%) passing accuracy post-NT (p = 0.304, η = .105). There was a no significant difference between the CON group (76.1 ± 3.1%) and NT group (77.0 ± 3.3%) Short+medium passes post-NT (p = 0.847, η = 0.004). CONCLUSIONS: This is the first study to examine the effects of Neurotracker on collegiate in-game soccer performance metrics related to in-game decision-making. While none of the metrics of interest were found to have a significant difference, passing accuracy was found to a have a moderate effect (η = .105) with the NT group increasing passing accuracy by 8.5% (pre: 63.2% vs post: 71.7%) compared to the CON group increasing by 3.5% (pre: 61.3% vs post: 64.8). Further research is needed utilizing multiple sites to increase sample size and examine a potential transfer effect through training with 3D-MOT given the practical significance of improved passing accuracy.

PURPOSE: Research has previously provided conflicting evidence on the relationship between bone mineral density (BMD), and joint loading. We sought to distinguish the relationships between hip joint moments during locomotion, obstacle negotiation, and bone mineral density of the proximal femur as well as clarify the moderating role of body mass on the relationships between hip joint moments during locomotion, obstacle negotiation, and bone mineral density of the proximal femur. METHODS: Forty women (57 + 7.9 years; height of 162 + 8.62 cm; weight of 81.21 + 19.32 kg) participated in this study. A DEXA scan and a series of randomized gait trials and obstacle negotiation gait trials at two obstacle heights (10” and 20”) were completed. Full-body motion was captured using the Vicon 460 motion measurement system. Analyses were performed to determine the significance between BMD and hip joint moments across normal and osteopenic/osteoporotic groups, independently for normal and obstacle negotiation gait. Pearson correlation coefficients were calculated, with and without allometric scaling procedures to determine the extent to which hip joint moments and BMD of the proximal femur, during normal gait and two obstacle negotiation heights, were influenced by body mass. Analysis was performed to determine the significance between BMD and hip joint moments across normal and osteopenic/osteoporotic groups. RESULTS: The results suggested a significantly negative relationship between hip joint moments and obstacle height in osteopenic/osteoporotic subjects (p < .05), while no significant relationships were found in healthy subjects. Average hip joint moments (flexion/extension) of osteopenic/osteoporotic subjects were 1.32 (Nm/Kg) in flat walking, 0.97 (Nm/Kg) at the low obstacle height and, 0.71 (Nm/Kg) at the low obstacle height. Healthy subjects’ average hip joint moments(flexion/extension) were 1.46 (Nm/Kg) in flat walking, 1.38 (Nm/Kg) at the low obstacle height and, 1.34 (Nm/Kg) at the low obstacle height. CONCLUSIONS: The results support a significant relationship between BMD and joint moment loading (internal rotation) specifically during high obstacle negotiation. Further efforts are needed to help further clarify the literature.

Introduction: Monitoring Training Load in soccer is used to achieve the best individualized performance outcomes and to prevent injuries. However, there is no clear recommendation for which ‘match duration’ should be used in the calculation of match Session Rating of Perceived Exertion Training Load (sRPE-TL) in NCAA DI women’s soccer. Therefore, the purpose of this study was to establish a duration standard to be used in the calculation of sRPE-TL in collegiate NCAA DI women’s soccer matches. A secondary aim was to investigate whether multiple positions require the use of different durations for the calculation of sRPE-TL. Methods: Seventeen athletes (means ± standard deviations: age 20 ± 1.1 yrs., height 170 ± 6.6 cm, weight 64.6 ± 7.0 kg) participated in this study. Repeated measures correlations were used to determine the relationship between the different sRPE-TL calculations and objective variables (e.g., GPS variables and HR-based variable). Data was analyzed using the rmcorr package in R Studio executing R. Alpha was set a-priori at p ≤ 0.05. Results: The s-RPE-TL using the four ‘minutes played’ durations (‘minutes played only’, ‘warm-up added’, ‘halftime added’, and ‘warm-up and halftime added’) were strongly correlated with TLS (r = .773, .776, .789, .786), total distance (r = .825, .813, .811, .798), number of sprints (r = .716, .717, .712, .711), HSD (r = .608, .615, .609, .612), and mechanical load (r = .738, .738, .734, .732). When separated by positions, the correlations between sRPE-TL and objective data were similar across all four ‘minutes played’ durations. Conclusions: Any of the ‘minutes played’ durations should be used to calculate match sRPE-TL values for the entire team. Multiple positions do not require the use of different durations for the calculation of sRPE-TL which facilitates sRPE-TL comparisons across positions.

Monitoring athletes’ workload has become common practice in sports and differs depending on the sport’s physical demands. Within volleyball, an inertial measurement unit can be utilized to track the number of jumps performed by players. However, other methods of measuring jump frequency are needed for teams without access to this equipment. The purpose of this study was to determine if volleyball athletes can accurately predict the number of jumps performed after training and matches when given a perceptual scale and if player position, session rating of perceived exertion (sRPE), and perceived sets played affected the players’ accuracy. Less than half of the team’s jump count estimations (23.2%) were within 25 of the actual number of jumps and over half of the players’ responses (58%) were within 50 of the measured number of jumps. A generalized estimating equation (GEE) with a binary response was used to investigate the impact of position, sRPE, and sets played. Position was the only variable to have a significant impact on jump count accuracy. Based on these results, a perceptual scale could be useful in better understanding players’ jump counts following training, but number of jumps allotted to each jump range and position could impact accuracy.

Correlations between sport performance and visual training have been previously demonstrated. However, it remains unclear if these relationships exist between visual tracking thresholds and in-competition decision-making metrics. Therefore, the purpose of this study was to investigate the relationship between visual tracking speed (VTS) and soccer-specific performance measures. 19 NCAA Division I soccer players VTS was measured from 1-core session on a 3-demensional multiple object tracking (3D-MOT) software NeuroTracker (NT) and soccer performance metrics were obtained from WyScout. Spearman’s rank order correlation coefficient was utilized to examine potential correlations between criterion variables. There was nonsignificant correlation between VTS score and passing accuracy (r = -0.380). However, there was a strong correlation found between consistency score and passing accuracy (r = 0.650). When examining players based on their positional role, for attacking players there were nonsignificant strong correlation with consistency and passing accuracy (r = 0.730). For defenders, consistency and defensive win rate had a strong correlation (r = 0.731). Although there was no significant correlation seen between VTS and decision-making variables when examining the entire team, there was a significant strong positive relationship between consistency scores and passing accuracy. Future research should seek to include multiple teams for improved sample size.

To assign emphasis to improving their pre-practice hydration status, in order to reduce the risk of sustaining a negative consequence of dehydration.

Gann, JJ, Andre, TL, Gallucci, AR, and Willoughby, DS. Effects of hypohydration on muscular strength, endurance, and power in women. J Strength Cond Res XX(X): 000-000, 2020-The purpose of this study was to determine the effects of dehydration on muscular strength, endurance, power, and perceptual measures in resistance-trained women. Ten resistance-trained women completed 2 bouts of exercise (1 repetition maximum [1RM] for bench press and angled leg press followed by 5 sets to failure of 75% of 1RM and vertical jump), either dehydrated (∼3% body mass) (DT) or heat-exposed with fluid replacement (HT). Paired t-tests revealed bench press 1RM was significantly lower for DT (42.7 ± 14.5 kg) compared with HT (44.1 ± 13.9 kg). No significant difference was found for leg press 1RM (DT = 216.1 ± 55.0 kg; HT = 223.4 ± 55.7 kg). There was also no difference in total reps completed for bench press (DT = 33.5 ± 5.0; HT = 33.0 ± 5.5) or leg press (DT = 42.6 ± 20.3; HT = 45.8 ± 19.7). There was no significant difference for vertical jump height (DT: 45.8 ± 5.2 cm, HT: 46.9 ± 6.0 cm). Ratings of perceived exertion (RPE) and session RPE were not significantly different between trials. Significant differences for perceived recovery status (DT: 5.1 ± 2.2, HT: 7.2 ± 1.1) and perceived readiness (DT: 4.2 ± 1.0, HT: 2.5 ± 0.5) indicate subjects expected impaired performance during DT. The current results suggest that previous night dehydration may have a negative impact on both bench press 1RM performance and perceptual feelings of recovery in resistance-trained women.

PURPOSE: To investigate the effects of chronic alcohol consumption on exercise-induced muscle damage of the knee extensors in young men. METHODS: Twenty-one males (age 21.9 ± 1.1 yr; weight 183.4 ± 27.6 lbs; height 174.0 ± 13.1 cm) performed 100 maximal eccentric contractions at 30 ° /sec of the knee extensors using their non-dominant leg. The isometric and isokinetic muscle strengths (60 ° /sec and 180 ° /sec ) were measured pre-exercise and immediately, 24 h, 48 h, 72 h, 96 h, and 120 h post-exercise. Muscle soreness and plasma creatine kinase (CK) activity were measured pre-exercise and 24 h, 48 h, 72 h, 96 h, and 120 h post-exercise. Data were analyzed using two-way repeated-measures ANOVA to determine the main effects of time (exercise), group (non-drinker vs. frequent drinker), and their interaction terms. RESULTS: There were significant main effects of time for isometric strength (F 6, 114 = 8.11, P < 0.001), isokinetic strength at both 60 ° /sec ( F 6, 114 = 11.02, P < 0.001) and 180 ° /sec (F 6, 114 = 9.88, P < 0.001), muscle soreness (F 5, 95 = 26.64, P < 0.001), and plasma CK activity (F 5, 70 = 5.15, P < 0.001). There were no significant effects of group or interaction for any of the variables. CONCLUSION: There was not an evident effect of chronic alcohol consumption on exercise-induced muscle damage in young men. This may likely be due to the small sample size, the relatively small magnitude of muscle damage, the time of alcohol consumption relative to the bout of exercise, and the between-subjects study design.

The aims of this study were to investigate the feasibility of an experiential learning initiative led by minority exercise science undergraduates and to observe the adaptations after a 10-week high-intensity functional training (HIFT) program in 34 underrepresented, hypertensive, and overweight/obese professional firefighters (PFF; age: 36.8 ± 11.0 years, body weight: 97.3 ± 21.5 kg, height: 181.7 ± 6.6 cm; BMI: 29.2 ± 4.9 kg/m2). Data were analyzed for muscular strength and endurance, cardiorespiratory endurance, body composition, agility, flexibility, and readiness for change. The PFFs trained two to three times weekly during their work shifts at vigorous intensity for 40 min. Their resting diastolic blood pressure and resting heart rate significantly decreased. Improvements in agility, muscular strength, and readiness for change were observed. This HIFT experiential learning initiative was feasible and beneficial and improved the PFFs’ health and physical fitness with limited resources. Accredited programs in exercise science participating in low-cost initiatives may aid in mitigating public service workers’ compensation and injury rates to better respond to occupational demands.