Practitioner Perceptions of Evidence-Based Practice in Elite Sport in the United States of America Fullagar, HHK, Harper, LD, Govus, A, McCunn, R, Eisenmann, J, and McCall, A. Practitioner perceptions of evidence-based practice in elite sport in the United States of America. J Strength Cond Res 33(11): 2897–2904, 2019—Practitioners' perceptions regarding the use and effectiveness of research evidence in sport is not well understood. The purpose of the present study was to examine practitioners' perceptions around the use, implementation, and barriers to evidence-based practice (EBP) in sport science in the United States of America (USA). A survey (28 items) was completed by 67 full-time staff who were a physical performance team member employed by universities or professional sporting organizations in the USA. Questions included the use of research, contribution of research areas, barriers to accessing and implementing EBP, and methods of feedback to the coach and players. All respondents (100%) stated they used research evidence in their performance/training program, ranking research as contributing most (largest contribution = 1 to smallest contribution = 4) to individualized preparation or recovery recommendations (1.98 ± 1.02). The top 3 preferred sources of information were “peer-reviewed research” (100% of respondents), “conferences/seminars” (76%), and “practitioners within your sport” (63%). Commonly reported perceived barriers between accessing and implementing research were “lack of staff” (accessing = 33%, implementing = 46%) “time” (accessing = 38%, implementing = 48%) and nonapplicable research (accessing = 33%, implementing = 37%), whereas “poor player compliance” was a clear barrier to implementing EBP (56%). Practitioners most preferred, and actual, method of feedback for coaching staff (87% for both) and players (94 and 95%, respectively) was “informal conversations/speaking.” Improved access to educational and financial resources, increased integration of staff in coach settings and understanding of player/coach contexts may help to alleviate barriers to EBP.

Anticipatory Salivary Cortisol and State Anxiety Before Competition Predict Match Outcome in Division I Collegiate Wrestlers Cintineo, HP and Arent, SM. Anticipatory salivary cortisol and state anxiety before competition predict match outcome in Division I collegiate wrestlers. J Strength Cond Res 33(11): 2905–2908, 2019—Anticipation of exercise and other stressors has been shown to result in physiological and psychological changes, which include increased levels of cortisol and anxiety. Combat sports, in particular, typically elicit robust anticipatory responses because of the distinct nature of these sports. Therefore, the purpose of this investigation was to examine the relationship between state anxiety scores, anticipatory cortisol response, and performance outcomes in college wrestlers. A secondary purpose was to determine the correlation between anticipatory cortisol and state anxiety scores. Twenty-six collegiate wrestlers were recruited to undergo saliva collection and to complete the State Anxiety Inventory before a wrestling match and again on a rest day in a time-matched, control session. Univariate analyses revealed that both salivary cortisol and anxiety were greater before competition than on a rest day. In addition, it was found that losers had higher levels of anticipatory cortisol and anxiety compared with winners. A significant correlation between salivary cortisol and anxiety was found as well. These data show that higher cortisol and anxiety may negatively affect performance. Athletes and coaches should work together to determine optimal levels of arousal and should aim to replicate this during both training and competition to ensure consistently high levels of performance through appropriate preparation.

Three-Year Longitudinal Fitness Tracking in Top-Level Competitive Youth Ice Hockey Players Cordingley, DM, Sirant, L, MacDonald, PB, and Leiter, JR. Three-year longitudinal fitness tracking in top-level competitive youth ice hockey players. J Strength Cond Res 33(11): 2909–2912, 2019—The purpose of this retrospective review was to report the physical and physiological development of top-level competitive male youth hockey players for 3 consecutive years (13, 14, and 15 years of age). Before each hockey season, the athletes (n = 103) underwent a fitness testing combine to assess aerobic, anaerobic, and musculoskeletal fitness. The tests performed included the height, body mass, body fat percentage determined by skinfolds, push-ups, chin-ups, plank, broad jump, grip strength 20-m shuttle run, Wingate bike test, and 5-10-5 shuttle test. Height and body mass increased with each consecutive year (p < 0.05) with no change in body fat percentage. Chin-ups, broad jump, and grip strength all improved with age (p < 0.001). However, push-ups only improved from 13 to 14 years of age (p < 0.001), whereas maximal plank duration decreased from 14 to 15 years of age (p < 0.05). The total distance covered during the 20-m shuttle run decreased from 14 to 15 years of age (p < 0.05). Absolute peak and average power increased with each age increase (p < 0.001), but relative peak and average power only increased from 13 to 14 years of age (p < 0.05). There was no change in the fatigue index with age. The 5-10-5 shuttle test improved with each age increase (p < 0.05). Over a 3-year period (13–15 years of age), there are many physical and physiological changes that occur in top-level competitive male hockey players. Having a better understanding of how these athletes develop could aid in the implementation of specific on- and off-ice training programs.

A Retrospective Analysis of Collegiate Athlete Blood Biomarkers at Moderate Altitude Morris, KL, Widstrom, L, Goodrich, J, Poddar, S, Rueda, M, Holliday, M, San Millian, I, and Byrnes, WC. A retrospective analysis of collegiate athlete blood biomarkers at moderate altitude. J Strength Cond Res 33(11): 2913–2919, 2019—Blood biomarkers are used to assess overall health and determine positive/negative adaptations to training/environmental stimuli. This study aimed to describe the changes in blood biomarkers in collegiate football (FB) (n = 31) and cross-country (XC) (n = 29; 16 women [FXC], 13 men [MXC]) athletes across a competitive season while training and living at a moderate altitude (1,655 m). This study used a database of previously collected hematological (complete blood count and serum ferritin) and muscle damage (lactate dehydrogenase and creatine kinase) blood biomarkers. Data were analyzed both within and between groups using linear mixed-model and variance component analyses, alpha = 0.05. All 3 groups had significant but different patterns of change in the measured biomarkers. Hematological blood biomarkers increased at different time points but remained within the normal reference ranges with greater between-subject vs. within-subject variability, suggesting no significant decrements to oxygen-carrying capacity across the season for FB, MXC, or FXC. Muscle damage biomarkers increased over time and exceeded the normal reference ranges, indicating cell damage pathology. However, it is also possible that the demands of training and competition might alter baseline values in these athletes, although this cannot be confirmed with the current experimental design. The patterns of change in the hematological and muscle damage biomarkers varied by sport discipline, suggesting that the training/competitive environments of these athletes influence these changes. Further studies should assess how much training, altitude, and nutrition influence these changes by using a more comprehensive set of biomarkers and related performance parameters.

Appendicular Body Composition Analysis: Validity of Bioelectrical Impedance Analysis Compared With Dual-Energy X-Ray Absorptiometry in Division I College Athletes Brewer, GJ, Blue, MNM, Hirsch, KR, Peterjohn, AM, and Smith-Ryan, AE. Appendicular body composition analysis: Validity of bioelectrical impedance analysis compared with dual-energy x-ray absorptiometry in Division I college athletes. J Strength Cond Res 33(11): 2920–2925, 2019—The purpose of this study was to evaluate validity of appendicular body composition measurements measured from a multifrequency bioelectrical impedance analysis (MF-BIA) compared with a dual-energy x-ray absorptiometry (DXA) criterion in Division I athletes. One hundred sixty male (n = 44) and female (n = 116) collegiate athletes were enrolled: Men's Cross Country (n = 15), football linemen (n = 29), Women's Soccer (n = 27), Women's Field Hockey (n = 27), Women's Cross Country (n = 13), Women's Gymnastics (n = 16), and Women's Lacrosse (n = 33). Appendicular fat mass (FM) of the arms (AFM, right AFM, left AFM) and legs (LFM, right LFM, left LFM), appendicular fat-free mass (FFM) of the arms (AFFM, RAFFM, LAFFM) and legs (LFFM, RLFFM, LLFFM), total body FM and FFM, and total body %fat were collected from both devices. MF-BIA significantly underestimated appendicular FFM of the arms (AFFM mean difference [MD]: −0.7 kg; RAFFM: −0.4 kg; LAFFM: −0.4 kg, p < 0.001) and legs (LFFM MD: −3.8 kg; RLFFM: −1.9 kg; LLFFM: −1.9 kg, p < 0.001), and FM of the legs (LFM MD: −2.5 kg; RLFM: −1.3 kg; LLFM: −1.3 kg, p < 0.001). There was no significant difference in appendicular FM measures of the arms (p = 0.174). All measures held true for male subjects and female subjects. Female subjects produced smaller differences compared with male subjects. The lack of validity, from raw and relative error, between the devices for most appendicular measures (FFM of arms and FFM and FM legs) and all total body measures (FM, FFM, and %fat) suggest that this MF-BIA may not be accurate in measuring a lean, athletic, population compared with DXA.

The Relationship Between Adductor Squeeze Strength, Subjective Markers of Recovery and Training Load in Elite Rugby Players Tiernan, C, Lyons, M, Comyns, T, Nevill, AM, and Warrington, G. The relationship between adductor squeeze strength, subjective markers of recovery and training load in elite Rugby players. J Strength Cond Res 33(11): 2926–2931, 2019—The adductor squeeze strength test has become a popular training monitoring marker, particularly in team sports. The aim of this study was to investigate the relationship between adductor squeeze strength scores, subjective markers of recovery and training load in elite Rugby Union players, because of limited research in this area. Nineteen elite male Rugby Union players completed daily monitoring markers (adductor squeeze strength and 5 selected subjective markers of recovery), over a 10-week preseason training period. Rate of perceived exertion (RPE) was collected to determine training load (session RPE; RPE × session duration) and to calculate weekly training load. Spearman’s correlation was used to analyze the relationship between adductor squeeze strength scores, subjective markers of recovery, and weekly training load. The results found that where adductor squeeze scores decreased, both perceived fatigue levels (r = −0.335; R2 = 11.2%; p < 0.001) and muscle soreness (r = −0.277; R2 = 7.7%; p < 0.001) increased. A weak correlation was found between Monday adductor squeeze strength scores and the previous week's training load (r = −0.235; R2 = 5.5%; p < 0.001) and Friday adductor squeeze strength scores and the same week's training load (r = −0.211; R2 = 4.5%; p < 0.05). These results show that adductor squeeze strength may provide coaches with a time-efficient, low‐cost objective, player monitoring marker. Additionally, the combination of adductor strength squeeze, with subjective markers, perceived fatigue, and muscle soreness, and appropriately planned training load may help coaches to optimize training adaptations by determining a player's training status.

Intrasession and Intersession Reliability of Countermovement Jump Testing in Division-I Volleyball Athletes Carroll, KM, Wagle, JP, Sole, CJ, and Stone, MH. Intrasession and intersession reliability of countermovement jump testing in Division-I volleyball athletes. J Strength Cond Res 33(11): 2932–2935, 2019—The countermovement jump (CMJ) is a reliable and noninvasive test of lower-body neuromuscular performance. Many of the investigations used to establish the reliability of CMJ have been conducted in a controlled environment (i.e., laboratory setting). To better inform coaches, reliability of key CMJ variables should be examined in a practical environment. This study assessed intrasession and intersession reliability of CMJ variables in NCAA D-I volleyball athletes. Eleven female volleyball players (age = 19.8 ± 0.8 years, height = 1.75 ± 0.07 m, body mass = 71.6 ± 8.9 kg) performed twice weekly CMJ testing on force platforms across 14 weeks of training. Dependent variables were CMJ height (CMJH), reactive strength index modified (RSIMOD), relative peak power (rPP), and countermovement depth (CM depth). Intraclass correlation coefficients (ICCs), coefficient of variation (CV), and typical error (TE) were calculated, along with Pearson correlation coefficients. Intrasession reliability revealed excellent reliability values for CMJH (ICC = 0.94, CV = 2.9 ± 2.4%, TE = 1.25) and RSIMOD (ICC = 0.93, CV = 4.7 ± 4.9, TE = 0.03). Good reliability values were observed for rPP (ICC = 0.79, CV = 6.1 ± 10.9%, TE = 4.48), with only moderate reliability for CM depth (ICC = 0.61, CV = 7.1 ± 10.9%, TE = 16.9). Intersession reliability indicated excellent reliability for CMJH (ICC = 0.92, CV = 3.2 ± 2.8%, TE = 1.4) and RSIMOD (ICC = 0.92, CV = 5.4 ± 4.3%, TE = 0.03). However, poor reliability was observed for rPP (ICC = 0.41, CV = 10.4 ± 15.4%, TE = 7.95) and CM depth (ICC = 0.39, CV = 7.7 ± 10.8%, TE = 6.42). These results suggest that in the context of weekly athlete monitoring, measures such as CMJH and RSIMOD exhibit the greatest reliability. Conversely, measures such as CM depth and rPP exhibit high levels of variability. Practitioners seeking to track jump performance over time should be cognizant of CM depth variability and its potential impact on CMJ variables.

Influence of Power Clean Ability and Training Age on Adaptations to Weightlifting-Style Training James, LP, Comfort, P, Suchomel, TJ, Kelly, VG, Beckman, EM, and Haff, GG. Influence of power clean ability and training age on adaptations to weightlifting-style training. J Strength Cond Res 33(11): 2936–2944, 2019—The purpose of this investigation was to determine whether weightlifting actions are a viable method for improving athletic performance among weaker, inexperienced lifters when compared with individuals with a greater power clean (PC) result, and hence weightlifting ability and experience. Two groups of males with distinctly different PC performances (higher performance [HP]: N = 8; body mass [BM] = 78.1 ± 4.0 kg; 1 repetition maximum [1RM] PC = 1.08 ± 0.09 kg·BM−1; lower performance [LP]: N = 8; BM = 82.6 ± 14.0 kg; 1RM PC = 0.78 ± 0.1 kg·BM−1) and resistance training age (HP: resistance training experience = 3.5 ± 1.2 years; LP: resistance training experience = 1.44 ± 1.50 years) undertook 10 weeks of training involving weightlifting derivatives, in addition to supplemental ballistic and plyometric exercises. Testing of athletic performance (represented by measures derived from the countermovement jump) occurred at baseline, after 5 weeks of training, and after 10 weeks of training. Both groups significantly improved across the majority of outcome variables after training (Hedges' g = 0.98–2.55, p ≤ 0.01–0.05). Only the HP participants experienced significant changes at midtest (g = 0.99–1.27, p ≤ 0.01–0.05), whereas no significant changes were revealed between midtest and posttest in this group. In contrast to this, the LP participants displayed a significant improvement in relative impulse (g = 1.39, p < 0.01) and rate of force development (g = 1.91, p < 0.01) during this final period (p < 0.01). As weaker, inexperienced lifters underwent a significant and meaningful enhancement in maximal neuromuscular measures after weightlifting derivative-focused training, practitioners should consider early implementation of such exercises. However, it is important for coaches to note that a delayed training effect might be present in weaker, less experienced lifters.

Comparison of Psychological and Physiological Responses to Imposed vs. Self-selected High-Intensity Interval Training Kellogg, E, Cantacessi, C, McNamer, O, Holmes, H, von Bargen, R, Ramirez, R, Gallagher, D, Vargas, S, Santia, B, Rodriguez, K, and Astorino, TA. Comparison of psychological and physiological responses to imposed vs. self-selected high-intensity interval training. J Strength Cond Res 33(11): 2945–2952, 2019—High-intensity interval training elicits similar physiological adaptations as moderate intensity continuous training (MICT). Some studies report greater enjoyment to a bout of high-intensity interval exercise (HIIE) vs. MICT, which is surprising considering that HIIE is more intense and typically imposed on the participant. This study compared physiological and perceptual responses between imposed and self-selected HIIE. Fourteen adults (age = 24 ± 3 years) unfamiliar with HIIE initially performed ramp exercise to exhaustion to measure maximal oxygen uptake (VO2max) followed by 2 subsequent sessions whose order was randomized. Imposed HIIE consisted of eight 60 seconds bouts at 80 percent peak power output (%PPO) separated by 60 seconds recovery at 10 %PPO. Self-selected HIIE (HIIESS) followed the same structure, but participants freely selected intensity in increments of 10 %PPO to achieve a rating of perceived exertion (RPE) ≥7. During exercise, heart rate, VO2, blood lactate concentration (BLa), affect (+5 to −5), and RPE were assessed. Physical Activity Enjoyment Scale was measured after exercise. Results showed higher VO2 (+10%, p = 0.013), BLa (p = 0.001), and RPE (p = 0.001) in HIIESS vs. HIIEIMP, and lower affect (p = 0.01), and enjoyment (87.6 ± 15.7 vs. 95.7 ± 11.7, p = 0.04). There was a significantly higher power output in self-selected vs. imposed HIIE (263.9 ± 81.4 W vs. 225.2 ± 59.6 W, p < 0.001). Data suggest that intensity mediates affective responses rather than the mode of HIIE performed by the participant.

Assessing Asymmetries in Change of Direction Speed Performance: Application of Change of Direction Deficit Dos'Santos, T, Thomas, C, Jones, PA, and Comfort, P. Assessing asymmetries in change of direction speed performance; application of change of direction deficit. J Strength Cond Res 33(11): 2953–2961, 2019—The aims of this study were to quantify asymmetries in change of direction (COD) performance using completion time and COD deficit, and determine its influence on asymmetry profiling of COD ability. A secondary aim was to evaluate the relationship between linear speed, 505 time, and COD deficit. Forty-three youth netball athletes (age: 15.4 ± 1.1 years, height: 1.71 ± 0.06 m, and mass: 63.3 ± 6.6 kg) performed the 505 for both left and right limbs and a 10-m sprint test. Asymmetries in 505 completion time and COD deficit were quantified for dominant (D) (faster) and nondominant (ND) (slower) directions. Paired sample t tests revealed significant differences between D and ND directions for 505 time and COD deficit (p < 0.0001, g = −0.53 to −0.60). Substantially greater asymmetries for COD deficit were observed compared with 505 time (p < 0.0001, g = 1.03). Only 2 subjects displayed an asymmetry ≥10% based on 505 times. Conversely, based on COD deficit, 21 subjects demonstrated asymmetries ≥10%. Large significant associations were observed between 505 time and COD deficit (r = 0.500–0.593, p ≤ 0.002). Large significant inverse associations were demonstrated between 10-m sprint time and COD deficit (r = −0.539 to −0.633, p ≤ 0.001), indicating that faster athletes had longer COD deficits. Nine subjects were classified differently for COD ability when comparing standardized scores for 505 time vs. COD deficit. Quantification of asymmetries in COD ability should be based on COD deficits; inspection of 505 times only could lead to misinterpretations of an athlete's COD symmetry and COD ability. Faster youth netball athletes demonstrate longer COD deficits; thus, researchers and practitioners are encouraged to improve their youth netball athletes' ability to rapidly decelerate, change direction, and reaccelerate from 180° turns.