bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Blood Flow Restriction Therapy on Recovery After Experimentally Induced Muscle Weakness and Pain
Authors: Wong Vickie , Dankel Scott J. , Spitz Robert W. , Bell Zachary W. , Viana Ricardo B. , Chatakondi Raksha N. , Abe Takashi , Loenneke Jeremy P. 
Published: August 2020

Abstract
Wong, V, Dankel, SJ, Spitz, RW, Bell, ZW, Viana, RB, Chatakondi, RN, Abe, T, and Loenneke, JP. The effect of blood flow restriction therapy on recovery after experimentally induced muscle weakness and pain. J Strength Cond Res 36(4): 1147–1152, 2022—The purpose was to determine if blood flow restriction with no external load could be used as a means of active therapy after experimentally induced fatigue and soreness. Twelve women and 7 men (aged 18–35 years) participated in a randomized controlled trial using a within-subject design. The study intervention was 3 consecutive visits. Visit 1 included the fatiguing/soreness-inducing protocol for the elbow flexors, which was performed only once during the study. Torque was measured before/after to confirm individuals began in a weakened state. Subjects then completed blood flow restriction therapy on one arm and the sham therapy on the other. Subjects performed elbow flexion/contraction with no external load on both arms. Torque was measured once more 10 minutes after the fatiguing/soreness-inducing protocol. Twenty-four hours later, soreness and torque were assessed in each arm, followed by another bout of therapy. Forty-eight hours after the initial visit, soreness and torque were measured again. There were no differences (median difference [95% credible interval]) in the recovery of torque between the blood flow restriction and sham therapy conditions at 10 minutes (0.5 [−2.7, 3.8] N·m), 24 hours (−2.34 [−6, 1.14] N·m), or 48 hours (−1.94 [−5.45, 1.33] N·m). There were also no differences in ratings of soreness at 24 hours (−2.48 [−10.05, 5.05]) or 48 hours (2.58 [−4.96, 10.09]). Our results indicate that this specific model of blood flow restriction therapy did not enhance the recovery of the muscle compared with a sham condition without the application of pressure.
Validity, Reliability, and Sensitivity to Exercise-Induced Fatigue of a Customer-Friendly Device for the Measurement of the Brain's Direct Current Potential
Authors: Valenzuela Pedro L. , Sánchez-Martínez Guillermo , Torrontegi Elaia , Vázquez-Carrión Javier , Montalvo Zigor , Kara Olga 
Published: August 2020

Abstract
Valenzuela, PL, Sánchez-Martínez, G, Torrontegi, E, Vázquez-Carrión, J, Montalvo, Z, and Kara, O. Validity, reliability, and sensitivity to exercise-induced fatigue of a customer-friendly device for the measurement of the brain's direct current potential. J Strength Cond Res 36(6): 1605–1609, 2022—This study aimed to determine the validity, reliability, and sensitivity to exercise-induced fatigue of the brain's direct current (DC) potential measured with a commercially available and customer-friendly electroencephalography (EEG) device and Omegawave (OW). The study was composed of 3 different experiments as follows: (a) we compared the DC potential values obtained simultaneously in 31 subjects with both OW and a research-quality EEG system; (b) 3 consecutive DC potential measurements with OW were taken at rest on the same day in 25 subjects for reliability analyses; and (c) sensitivity to fatigue was assessed in 9 elite badminton players through the measurement of the DC potential with OW—as well as other fatigue-related measures (e.g., Hooper's index, heart rate variability, jump ability, and simple and complex reaction times)—24 hours after both a day of rest and of strenuous exercise, which were performed in a crossover and randomized design. The DC potential measured with OW was reliable (intraclass correlation coefficient = 0.97) and significantly correlated to that of EEG (r = 0.55, p = 0.001), although significant differences were observed between systems (p < 0.001). Compared with the rest day, strenuous exercise resulted in an impaired Hooper's index (p = 0.010) and jump ability (p = 0.008), longer simple (p = 0.038) and complex reaction times (p = 0.011), and a trend toward sympathetic dominance (standard deviation of normal to normal R-R intervals, p = 0.042; root mean square of differences between consecutive R-R intervals, p = 0.068). In turn, no significant differences were found between sessions for the DC potential (p = 0.173). In summary, the DC potential measured with OW was reliable and modestly correlated to that measured with EEG, but no differences were observed in response to the delayed fatigue (after 24 hours) elicited by strenuous exercise in elite athletes.
Relationship Between Strength and Conditioning Assessments and Rowing Performance in Female Collegiate Athletes
Authors: Folk Amanda L. , Garcia Christina A. , Whitney Samuel H. , Kovacs Sara J. 
Published: August 2020

Abstract
Folk, AL, Garcia, CA, Whitney, SH, and Kovacs, SJ. Relationship between strength and conditioning assessments and rowing performance in female collegiate athletes. J Strength Cond Res 36(6): 1618–1621, 2022—The purpose of this study was to examine the relationship between strength and conditioning variables and rowing performance, as measured by a 2000 m ergometer time, in female collegiate rowers. Twenty-four female collegiate rowers qualified for this study by completing both types of assessments and a demographic questionnaire. Pearson correlation coefficients (r) were used to determine the association between the total 2000 m ergometer time and each strength and conditioning assessment. The assessments included a 1 repetition maximum (1RM) squat and a 1RM hang clean. After this, all significant correlations were placed in a stepwise linear regression analysis to predict the total 2000 m ergometer time. The 1RM squat and 1RM hang clean correlated with 2000 m ergometer performance (p = 0.034 and p = 0.002, respectively). Only the 1RM squat emerged as a predictor of 2000 m ergometer performance. This study highlights that the 1RM squat may be a way to predict rowing performance and build successful female collegiate rowing teams.
A Congested Match Schedule Alters Internal Match Load and Affects Salivary Immunoglobulin A Concentration in Youth Soccer Players
Authors: Mortatti Arnaldo Luis , Oliveira Romerito Sóstenes Canuto de , Pinto Júlio Cesar Barbosa de Lima , Galvão-Coelho Nicole Leite , de Almeida Raíssa Nóbrega , Aoki Marcelo S. , Moreira Alexandre 
Published: August 2020

Abstract
Mortatti, AL, Oliveira, RSCd, Pinto, JCBdL, Galvão-Coelho, NL, Almeida, RN, Aoki, MS, and Moreira, A. A congested match schedule alters internal match load and affects salivary immunoglobulin A concentration in youth soccer players. J Strength Cond Res 36(6): 1655–1659, 2022—The aim of this study was to analyze the effects of a congested match schedule (CMS) undertaken after a tapering week, on internal match load (IML) and salivary immunoglobulin A (SIgA) concentration in 12 youth soccer players (16.6 ± 0.5 years; 175 ± 8 cm; 65 ± 8 kg) who performed 4 official matches within a 4-day period. Internal match load was determined using the session-rating of perceived exertion method and the competitive strain (CS) and monotony index (MI) were also determined. Saliva sampling was conducted, before the last training day of a tapering week (training) preceding the CMS, 60 minutes before the first match (match-1), and 22 hours after match 4 (postmatch 4). Salivary immunoglobulin A was analyzed by ELISA. The results of the analysis of variance with repeated measures showed a significant difference for IML across the matches (p < 0.001). A significant reduction in SIgA was observed from prematch 1 to postmatch 4 (p = 0.019). Regarding the change in SIgA (ΔSIgA), 58.3% of the players presented values equal/higher than the minimal detectable change. A large within-individual correlation was observed between ΔSIgA and MI and CS (r = 0.71 and r = 0.72: p < 0.01, respectively). The current findings suggest that youth players participating in a CMS may present a decrease in mucosal immunity function. In addition, data suggest that the MI and CS may be used as valuable markers for monitoring competition load during CMS in youth soccer players.
Psychophysiological Stress Markers During Preseason Among Elite Female Soccer Players
Authors: Botelho Renata , Abad Cesar C.C. , Spadari Regina C. , Winckler Ciro , Garcia Márcia C. , Guerra Ricardo L.F. 
Published: August 2020

Abstract
Botelho, R, Abad, CCC, Spadari, RC, Winckler, C, Garcia, MC, and Guerra, RLF. Psychophysiological stress markers during preseason among elite female soccer players. J Strength Cond Res 36(6): 1648–1654, 2022—This study aimed to investigate changes and correlations between mood states and various physiological stress markers after a 7-week preseason period among elite female soccer players. Twenty-four elite female soccer players participated in this study (26.4 ± 3.7 years). Their internal training load, mood states, day and evening salivary testosterone and cortisol concentrations, blood creatine kinase concentration (CK), and heart rate variability (HRV) were assessed during the first week of preseason (PRE), and again 7 weeks after a systematic training period (END). After the preseason, there were significant increases in subject negative mood scales (p ≤ 0.03; Effect Size [ES] > 0.60), total mood scores (p = 0.01; QI = 100/0/0; ES = 1.32), day and evening testosterone and cortisol concentrations (p ≤ 0.03; ES > 0.54), and CK concentrations (p = 0.01; QI = 100/0/0; ES = 1.54). Correlations were found between cortisol and tension (r = 0.53 and 0.60; p ≤ 0.02), cortisol and confusion (r = 0.75; p = 0.01), and cortisol and the LF/HF index of HRV (r = −0.52; p = 0.04). Mood states (except vigor), salivary testosterone, and cortisol concentrations, as well as CK, showed significant changes after a 7-week systematic training system. The cortisol was the factor most highly related to various mood states (including tension and confusion), and with the HRV indices. Coaches and researchers can use these data to design, monitor, and control soccer training programs, in particular throughout the preseason period.
Greater Fitness Is Associated With Improved Functional Movement Characteristics in Explosive Ordnance Disposal Technicians
Authors: Hernández Lisa M. , Coffin Stephanie D. , Taylor Marcus K. 
Published: August 2020

Abstract
Hernández, LM, Coffin, SD, and Taylor, MK. Greater fitness is associated with improved functional movement characteristics in explosive ordnance disposal technicians. J Strength Cond Res 36(6): 1731–1737, 2022—Low fitness and poor functional movement (FM) have been linked to higher musculoskeletal injury risk. The FM Screen (FMS) and Y-Balance Test (YBT) are useful indicators of potential injury risk in military personnel. U.S. Navy Explosive Ordnance Disposal (EOD) technicians are the premier combat force for countering explosive hazards and must operate in austere environments. To safeguard health and mission success, it is critical to assess factors related to injury risk in this specialized military population. This study evaluated the relationship between fitness and FM characteristics in 64 male EOD technicians (mean age ± SD = 34.2 ± 7.0 years). Body fat percentage (BF%), maximum volume of oxygen uptake (V̇o
2max), muscular strength, and FM (i.e., FMS, YBT) were assessed. Body fat percentage and V̇o
2max were associated with FMS and YBT scores (all p < 0.05). A nonlinear model further revealed that the group with the lowest V̇o
2max values had the bottommost FMS and YBT scores (all p < 0.01), but FM scores did not differ among those with a higher V̇o
2max, implying a “threshold” effect. No correlations were observed with muscular strength. By characterizing the unique and shared contributions of BF% and V̇o
2max, and exploring the nonlinear relationship between V̇o
2max and FM, this study expands on accruing data that indicate individuals who are more physically fit have better FM and lower injury risk. Although muscular strength is a critical element of overall fitness, body composition and cardiorespiratory fitness may more strongly influence FM and injury risk.
The Effects of Physical Fitness on Postactivation Potentiation in Professional Soccer Athletes
Authors: Guerra Mauro A. , Caldas Leonardo C. , Souza Helder L. , Tallis Jason , Duncan Michael J. , Guimarães-Ferreira Lucas 
Published: August 2020

ABSTRACT
Guerra, MA Jr, Caldas, LA, Souza, HL, Tallis, J, Duncan, MJ, and Guimarães-Ferreira, L. The effects of physical fitness on postactivation potentiation in professional soccer athletes. J Strength Cond Res 36(6): 1643–1647, 2022—To investigate the relationship of the response to postactivation potentiation (PAP) with scores of physical fitness. Twenty-four professional male soccer players undertook tests of agility, muscular power, aerobic capacity, and body composition. Conditioning activities (CAs) were performed consisting of plyometrics exercises and sprints with sled towing. In the first and second sessions, body composition, agility, power, and aerobic capacity were assessed. At the third session, countermovement jumps (CMJ) were performed with 1, 3, and 5 minutes after the execution of the CA. Significant differences were found for CMJ height 1, 3, and 5 minutes after the CA compared with baseline values (3.58, 5.10, 5.48%, respectively). There was a significant positive correlation between the level of general physical fitness and PAP (CMJ height increase) 5 minutes after (r = 0.73). When the athletes were divided into groups with higher and lower physical fitness, the CA caused a significant increase in CMJ height in both groups, but a significant difference (p < 0.05) was observed at all times after PAP induction, with better performance in higher versus lower fitness level. The results suggest that plyometrics exercises associated with sled towing sprints as a CA result in an increase in CMJ performance in athletes and that physical fitness directly influences the PAP occurrence, with higher fit players demonstrating an enhanced PAP response.
Influence of Training Schedules on Objective Measures of Sleep in Adolescent Academy Football Players
Authors: Brown Georgia A. , Veith Stella , Sampson John A. , Whalan Matthew , Fullagar Hugh H.K. 
Published: August 2020

Abstract
Brown, GA, Veith, S, Sampson, JA, Whalan, M, and Fullagar, HHK. Influence of training schedules on objective measures of sleep in adolescent academy football players. J Strength Cond Res 34(9): 2515–2521, 2020—Football academy settings may pose risks to adolescent athletes achieving sufficient sleep because of the contextual challenges these players face (e.g., psychosocial pressure, changes in training, competition, and academic stress). Given the importance of sleep to overall health as well as physical athletic development and injury risk, this study aimed to investigate whether differences in training schedules (morning vs. evening training sessions) affected objective measures of sleep in adolescent academy football (soccer) players. Twelve academy players (mean age 14.18 ± 1.36 years) wore an ActiGraph accelerometer on nights before, and nights of, training days in 2 separate weeks where morning (09:00–11:00 hours) and evening (18:00–20:00 hours) training occurred. Objective sleep parameters and training load data were collected. Night-time sleep periods were categorized as sleep preceding morning training, preceding evening training, or after evening training. One-way univariate and multivariate analyses of variance for repeated measures were performed to determine the impact of the training schedule on sleep. Significance levels were set at p < 0.05. The total sleep time was below the recommended guidelines (<8 hours) across conditions. A large significant effect of the training schedule on time attempted to fall asleep (p = 0.004, effect size [ES] = 0.40) and time of sleep (p = 0.003, ES = 0.41) was present, with post-evening sessions resulting in the latest times. Overall, the players' sleep behavior was resilient to changes in training schedules. However, the low sleep durations (and potential risks to physical performance/injury) suggest that sleep education coupled with practical interventions are required in this cohort.
Influence of Second Generation Oral Contraceptive Use on Adaptations to Resistance Training in Young Untrained Women
Authors: Dalgaard Line B. , Jørgensen Emil B. , Oxfeldt Mikkel , Dalgaard Emil B. , Johansen Frank T. , Karlsson Mads , Ringgaard Steffen , Hansen Mette 
Published: August 2020

Abstract
Dalgaard, LB, Jørgensen, EB, Oxfeldt, M, Dalgaard, EB, Johansen, FT, Karlsson, M, Ringgaard, S, and Hansen, M. Influence of second generation oral contraceptive use on adaptations to resistance training in young untrained women. J Strength Cond Res 36(7): 1801–1809, 2022—The study purpose was to determine effects of using second generation oral contraceptives (OC) on muscle adaptations to resistance training in young untrained women. Twenty users and 18 nonusers of OC completed a 10-week supervised progressive resistance training program. Before and after the intervention, muscle cross-sectional area (mCSA) of the quadriceps was measured using magnetic resonance imaging and muscle fiber CSA (fCSA) was determined by immunohistochemistry. In addition, body composition (DXA, fat mass/fat-free mass), maximal isometric muscle strength (dynamometry), 5 repetition maximum (5RM) leg press strength, counter movement jump (CMJ) height, and average power using a modified Wingate test were determined. Serum hormone analysis ensured OC compliance and 4-day food records documented dietary intake. After the training period, quadriceps mCSA (OC: 11.0 ± 6.0% vs. non-OC: 9.2 ± 5.0%, p = 0.001), type II fCSA (OC: 19.9 ± 7.9% vs. non-OC: 16.6 ± 7.2%, p = 0.05), muscle strength (knee extension, knee flexion and 5RM, p < 0.001), and functional power (CMJ, AP, p < 0.001) were significantly increased with no significant difference between the groups. However, a tendency toward a greater increase in fat-free mass (FFM) in the OC group was observed (OC: 3.7 ± 3.8% vs. non-OC: 2.7 ± 3.5%, p = 0.08). Collectively, use of second generation OCs in young untrained women did not significantly improve adaptations to 10 weeks of resistance training compared with nonusers. The trend toward greater gains in FFM in the OC group warrant future studies.
Blood Flow Restriction at High Resistance Loads Increases the Rate of Muscular Fatigue, but Does Not Increase Plasma Markers of Myotrauma or Inflammation
Authors: Winchester Lee J. , Morris Cody E. , Badinger Joseph , Wiczynski Teresa L. , VanWye William R. 
Published: August 2020

Abstract
Winchester, LJ, Morris, CE, Badinger, J, Wiczynski, TL, and VanWye, WR. Blood flow restriction at high resistance loads increases the rate of muscular fatigue, but does not increase plasma markers of myotrauma or inflammation. J Strength Cond Res 34(9): 2419–2426, 2020—High-load resistance training and blood flow restriction (BFR) training at low loads both promote protein synthesis and growth through different cell signaling mechanisms. Therefore, co-activation of these pathways could result in a synergistic effect for additional growth enhancement. The purpose of this study was to evaluate how BFR effects performance and physiological responses after an acute bout of high-load barbell squat training. Twelve resistance-trained, college-aged men and women performed 5 sets of barbell squats at 75% of 1 repetition maximum until failure under traditional (TRAD; control) or intermittent BFR conditions. Perceived limb pain and number of repetitions performed were recorded after each set. Blood samples were collected at baseline and 1-hour postexercise after each trial for analysis of myoglobin and interleukin-6 (IL-6). An alpha level of p < 0.05 was used to determine significance. Blood flow restriction trial performance significantly declined at set 3 and was lower than performance during control, whereas control performance did not decrease until set 5. Perceived limb pain was statistically increased with BFR use for the whole trial and was significantly higher with BFR during set 3 than observed during TRAD. Plasma myoglobin and IL-6 were significantly increased after both trials when compared with baseline, but were not significantly different between trials. Intermittent BFR use during high-load barbell squats increases the rate of muscular fatigue and perceived limb pain, but does not increase muscular damage or inflammatory response. Data obtained from this study can be used by fitness professionals as a means of potentially enhancing the rate of muscular hypertrophy.
Ciliary Neurotrophic Factor Receptor rs41274853 Polymorphism Is Associated With Weightlifting Performance in Japanese Weightlifters
Authors: Homma Hiroki , Kobatake Naoyuki , Sekimoto Yusuke , Saito Mika , Mochizuki Yukina , Okamoto Takanobu , Nakazato Koichi , Nishiyama Tetsunari , Kikuchi Naoki 
Published: August 2020

Abstract
Homma, H, Kobatake, N, Sekimoto, Y, Saito, M, Mochizuki, Y, Okamoto, T, Nakazato, K, Nishiyama, T, and Kikuchi, N. Ciliary neurotrophic factor receptor rs41274853 polymorphism is associated with weightlifting performance in Japanese weightlifters. J Strength Cond Res 34(11): 3037–3041, 2020—At least 69 genetic markers are associated with power athlete status. In the present study, we investigated the genotype frequency of the ciliary neurotrophic factor receptor (CNTFR) rs41274853 polymorphism and the association between specific CNTFR genotype and weightlifting performance in Japanese weightlifters. One hundred sixty-five Japanese weightlifters (103 men and 62 women) and 338 controls (122 men and 216 women) participated in the present case-control study. Saliva samples were collected using the Oragene DNA self-collection kit and genotyping for the CNTFR (rs41274853) polymorphism was performed using the TaqMan assay. A questionnaire, noting each subject's best record in an official weightlifting competition, was used to obtain the weightlifting performance. The frequencies of the CNTFR genotypes CC, CT, and TT were 56, 32, 12% in the weightlifters, and 53, 40, and 7% in the controls, respectively. There was no significant difference in CNTFR genotype frequencies between the weightlifters and controls. However, the frequency of the CT + TT genotype was significantly higher in international-level weightlifters than in the national-level weightlifters. The relative value per body weight of snatch, clean, and jerk, and total record were significantly higher in the athletes with CT + TT genotype than in the athletes with CC genotype (p < 0.05). Our results suggest that the CNTFR rs41274853 CT + TT genotype is associated with weightlifting performance in Japanese weightlifters. The CNTFR rs41274853 polymorphism may enable coaches to develop tailor-made training programs for individual athletes. In addition, strength and conditioning coaches could benefit from genetic information when assessing potential athletic talents and creating strength training programs for their athletes.