Increased Anxiety and Decreased Confidence Lead to Poorer Short-Passing Performance in Collegiate Soccer Players

Introduction: Competitive soccer players are required to perform short passing under stressful conditions; their success may be related to their self-confidence and anxiety levels. The purpose of this study was to examine the relationship between short-passing ability and anxiety and self-confidence among collegiate soccer players. Methods: Seventeen Division III collegiate soccer players (20.0 ± 1.0 years, 65% female) completed the Athletic Coping Skills Inventory (ACSI), Sport Competition Anxiety Test (SCAT), Trait Sport-Confidence Inventory (TSCI), and Competitive State Anxiety Inventory-2 (CSAI-2R) and the Loughborough Soccer Passing Test (LSPT). Spearman’s rho (rs) was used to identify if a relationship between these inventories and LSPT time existed. Results: Mean LSPT total time was 55.7 ± 12.0 seconds. We observed positive relationships between SCAT and LSPT total time (rs = .51, p = .04) and CSAI-2R and LSPT total time (rs = .55, p =.03). Furthermore, a strong negative relationship was found between TSCI and LSPT total time (rs = -.68, p = .004). Conclusions: There is a relationship between anxiety, confidence and short-passing performance in collegiate soccer players. Coaches should consider interventions to decrease players’ anxiety and improve self-confidence in preparation for soccer competition.

Comparison of Inter- and Intra-Individual Neuromuscular Patterns of Responses During Moderate-Load Bilateral Leg Extension Exercise

Introduction: This study examined the electromyographic (EMG) and mechanomyographic (MMG), amplitude (AMP) and mean power frequency (MPF) responses during bilateral, leg extension exercise performed to failure at a moderate (70% one-repetition maximum [1RM]) load. Methods: Eleven men completed a 1RM and repetitions to failure at 70% 1RM of the leg extension. The EMG and MMG signals were recorded from the right and left vastus lateralis. Polynomial regression analyses were used to determine individual and composite, normalized neuromuscular responses for both limbs. Results: For EMG AMP, both limbs demonstrated positive, quadratic relationships. For EMG MPF, the right limb demonstrated a negative, cubic relationship and the left limb demonstrated a negative, quadratic relationship. For MMG AMP, the right limb demonstrated a positive, quadratic relationship and the left limb demonstrated a positive, linear relationship. For MMG MPF, both limbs demonstrated negative, linear relationships. 18-45% of the subjects demonstrated the same responses as the composite for the EMG and MMG signals. 14% of the subjects demonstrated the same direction and pattern of response for the right and left limb intra-individual responses. Conclusions: The variability in the inter- and intra-individual responses highlight the necessity to report individual neuromuscular responses when examining fatiguing resistance exercise.

No Effect of Transcranial Direct Current Stimulation on Anaerobic Test Performance in Resistance-trained Individuals

Introduction: Transcranial direct current stimulation (tDCS) sends a weak electrical current through the cerebral cortex. tDCS has been shown to be effective in longer activities (>75s) but minimal research has been performed with short, anaerobic tests. The purpose of this study was to determine the effect of tDCS on Wingate Anaerobic Test (WAnT) performance. Methods: Fifteen young, resistance-trained adults (23.7±2.7 years; BMI 24.9±2.6 kg×m-2; 12 males) volunteered for this study. Electrodes were placed at T3 and FP2 for anodal stimulation of the insular cortex (IC), and 2mA of current was supplied for 20 minutes; after a short rest period, subjects performed a WAnT. Dependent variables included peak/mean/relative power, peak heart rate (HR) and rating of perceived exertion (RPE). Experimental and sham conditions were utilized. Paired-samples t-tests were used to determine the effect of tDCS on the dependent variables. Results: Peak power in the experimental condition (1,019.0±237.5W) was not different than that of the sham (1,008.3±240.4W; p=.638). There were no differences in any other WAnT variables, and no differences in peak HR or RPE (all p>.05). Conclusions: The results from this study suggest that tDCS in resistance-trained individuals is not effective in improving performance on an anaerobic test. In addition, it is still considered experimental and its ethical use is questionable.

Alterations in Surface Electromyography of the Upper Leg Muscles at Specified Respiratory Exchange Ratio Thresholds Ranges During a Maximal Exercise Test

Introduction: Assessing muscle electromyography (EMG) in conjunction with physiological alterations to exercise may be valuable to determine a more holistic approach to exercise-induced fatigue. Methods: Thirteen, recreationally trained individuals (n = 7 female, n = 6 males) underwent a maximal exercise test. Throughout the test, physiological variables were measured in addition to surface electromyography (sEMG) of the upper legs. Physiological and sEMG data was then grouped in to four category thresholds based on respiratory exchange ratios (RER) greater than 0.95. Results: There was a main effect of group (p < 0.001) as an increase in exercise intensity assessed by RER threshold ranges resulted in a subsequent reductions in sEMG frequencies with the exception of the sEMG frequencies recorded at VO2peak (p < 0.055). Conclusions: Upper leg sEMG frequencies decrease with increases in high intensity exercise, with the exception of near maximal loads.

NFL Draft Prep Players Improve 40-Yard Run Times and Foot-Ground Kinetics

Introduction: Linear speed is a discriminant factor between drafted and undrafted American football players into the National Football League. Linear speed is influenced by foot-ground contact time and the magnitude of vertical ground reaction force. The aim of this study was to determine if foot-ground kinetics during speed running could be modified through participating in a 6-week NFL draft preparation camp. Methods: To evaluate foot-ground kinetics, 16 American football players ran on an instrumented treadmill for 5 seconds at 6.5 m/s. Linear speed was measured during a 40-yard (36.6 m) outdoor run. Pre- and post-camp linear speed times, stance-averaged vertical ground reaction forces (vGRF, kg/N), foot-ground contact time (msec), and vertical impulse (kg/N * s) were examined using paired t-tests, p<.05. Results: Linear speed times significantly improved [(pre, 4.8±0.2 vs. post, 4.6±0.2 sec), t(15)=13.8, p<.001)], and foot-ground contact time significantly decreased for the right limb [(pre, 177+3.2 vs. post, 168+2.2 ms), t(15)=2.21, p=.043]. Mean vertical impulse and stance-averaged GRF for both limbs remained unchanged, p>.05. Conclusions: Linear speed and selected foot-ground kinetics are modifiable in NFL draft prep players. Training appears to lower 40-yard run times and foot-ground contact time.

Mental State as a Governor of Human Performance

For decades, athletes and coaches have touted the magnitude of the mind and its governance in human performance. Bobby Jones once stated that “golf is a game played on a five-inch course, the distance between your ears.” Sport psychologists and mental performance coaches collaborate with athletes in an effort to find, define, and replicate the optimal mental state when performing. The optimal mental state is often referred to as the “zone”, or “flow.” This is a state in which an athlete performs to the best of his or her ability”. While there is some understanding of this mental state, questions remain as to what extent the mind can impact human performance and/or affect physiology. Can one’s unwavering belief (perception) in their ability to accomplish a task at hand upregulate physiological qualities that determine such capacities? The breaking of a milestone in human performance, the sub 4:00 minute mile and the subsequent efforts certainly allows us to entertain the aforementioned question.

Relationship Between Physiological Fatigue and Muscular Fatigue Assessed Utilizing Surface Electromyography Wearable Technology

Introduction: The purpose of the study was to assess the relationship between upper leg muscle fatigue and physiological fatigue during a maximal exercise test. Methods: A total of 13, trained athletes participated and were tested for maximal oxygen uptake (VO2peak). Throughout the test, oxygen uptake respiratory exchange ratio (RER), and heart rate (HR) were recorded simultaneously with surface electromyography (sEMG) electrodes utilizing wearable sEMG compression short technology. Results: During the maximal exercise test, there were significant positive relationships between Muscle Load and all physiological measures (p < 0.001 for all) and significant negative relationships between sEMG frequency and Muscle Load and all physiological measures of fatigue (p < 0.001 for all). Conclusions: Using sEMG wearable compression short technology may be a useful way to measure and monitor muscle strain and fatigue, primarily outside of a laboratory setting.