Conditioning Coaches Research Articles

From Ground Up: Increasing Pitching Velocity through Lower-Limb Training

Pitching velocity is a crucial factor in effective baseball pitching performance. Upper-body-focused training is prevalent in baseball training to increase pitching velocity. However, significant pitchers, including youth league baseball players, suffer from upper body injuries due to the heavy training load of the throwing arm. This article emphasizes lower-body training to increase baseball pitching velocity. Three step-by-step recommended activities, with accompanying research support, include power training in the lower limbs, exploring and maintaining optimized stride length, and timing and mechanics of pitching sequences. The suggested lower body focused training will be beneficial in increasing pitching velocity and reducing the risk of injuries in the throwing arm. These recommendations are crucial for young baseball players, youth baseball coaches, strength coaches, and parents who aim to improve pitching performance while addressing concerns about overtraining and injury prevention.

Effects of a Short-Term Detraining Period on the Physical Fitness in Elite Youth Soccer Players: A Comparison Between Chronological Age Groups.

Padrón-Cabo, A, Lorenzo-Martínez, M, De Dios-Álvarez, V, Rey, E, and Solleiro-Durán, D. Effects of a short-term detraining period on the physical fitness in elite youth soccer players: a comparison between chronological age groups. J Strength Cond Res XX(X): 000-000, 2024-The aim of this study was to examine the effects of a 2-week in-season training cessation on neuromuscular and endurance performance in 2 different age groups of elite youth soccer players. A total of 30 players belonging to the under-15 (U15, n = 17) and under-17 (U17, n = 13) age groups of a Spanish professional soccer academy participated in the study. The following tests were assessed before and after the training cessation period: squat jump (SJ), countermovement jump (CMJ), 20-m sprint with 5-m and 10-m split times, modified 505 change of direction, and 30-15 Intermittent Fitness Test (30-15 IFT). The results showed significant and similar performance impairments between the 2 age groups in SJ (p = 0.020), CMJ (p = 0.044), 20-m sprint (p < 0.001), and 30-15 IFT (p < 0.001). The U17 players evidenced greater impairment than the U15 players in 5-m (p = 0.006) and 10-m (p = 0.002) sprint performance. However, there was no significant change (p = 0.070) in the players' change of direction performance. These findings provide valuable information for strength and conditioning coaches, suggesting the need for targeted interventions to mitigate the effects of detraining on neuromuscular and endurance performance during short-term in-season training cessation periods in elite youth soccer players. Special attention should be paid to maintaining sprint performance during short-term detraining periods in U17 players.

Resistance Training Prescription During Planned Deloading Periods: A Survey of Strength and Conditioning Coaches Across Varying Sporting Codes.

De Marco, K, Goods, PSR, Baldwin, KM, Hiscock, DJ, and Scott, BR. Resistance training prescription during planned deloading periods: A survey of strength and conditioning coaches across varying sporting codes. J Strength Cond Res XX(X): 000-000, 2024-The aim of this study was to investigate the resistance training (RT) prescription practices of strength and conditioning coaches throughout 4 common planned deloading periods (taper, competitive season, tournament, and travel). An anonymous online survey was shared globally to coaches, with data from 204 subjects included in analysis (current level of athlete coached: world class n = 68, elite/international n = 62, highly trained n = 64, trained n = 10). Coaches only provided answers about prescription for deloading periods, which they reported encountering. Where a coach indicated not prescribing RT for specific deloading periods, they detailed any barriers preventing RT prescription. Weekly deload RT prescription was typically reported as follows: 1-2 sessions, 30-60 minutes, 1-3 sets, 1-6 repetitions, and between 60 and 84% 1 repetition maximum. Most coaches reported decreasing volume during all deloading periods (taper: 89.1% [163/183 respondents], competitive season: 70.4% [133/189], tournament: 84.1% [74/88], travel: 74.6% [88/118]), with the most common reduction in RT volume reported as 0-25%. Most coaches also decreased intensity during a taper (52.9% [82/155]), tournament (54.8% [40/73]), and travel (53.6% [52/97]), with a 0-25% reduction the most common. Travel had the highest incidence of coaches not prescribing RT (38.5% [75/195]). The most cited barriers by these subjects were "scheduling/time" (60.0% [45/75]) and "lack of equipment and facilities" (57.3% [43/75]), which were also common in other periods. To address common barriers experienced by coaches, researchers should investigate time-efficient RT strategies requiring minimal equipment for periods of planned deloading to maintain training stimulus.

Unveiling Gaps in High School Strength and Conditioning: CSCS Certification, Coaching Leadership, and Facilities.

Judge, LW, Marsh, JP, Petersen, JC, Pearson, D, and Bellar, D. Unveiling gaps in high school strength and conditioning: CSCS certification, coaching leadership and facilities. J Strength Cond Res XX(X): 000-000, 2024-The aim of this study was to examine the prevalence of Certified Strength and Conditioning Specialist (CSCS) and/or dedicated strength coaches overseeing strength and conditioning facilities (SCFs) at the high school level in a Southwestern state. An online survey, comprising 72 items based on a validated instrument, collected data on SCFs from high school athletic directors statewide. A total of 245 surveys were completed representing a 17.5% response rate. Descriptive, Pearson correlation, chi-square, and ANOVA analyses were conducted with an a priori alpha level of p < 0.05 established. The results revealed that only 9.4% of SCF supervisors held CSCS certification, 27.8% lacked certification, and 62.9% did not have a dedicated strength coach overseeing the SCF. Facilities led by CSCS coaches had several areas of greater equipment resources, including bench press stations (F [2, 244] = 5.143, p = 0.006), squat stations (F [2, 244] = 3.570, p = 0.030), and power clean stations (F [2, 244] = 4.573, p = 0.011). This study highlights the importance of prioritizing safety considerations and meeting the developmental needs of high school athletes by addressing the absence of CSCS certifications and dedicated strength coaches overseeing SCFs. The scarcity of CSCS-credentialed coaches in high schools is troubling, considering adolescent athletes' developmental needs and recently enacted National Collegiate Athletic Association Division I safety standards for strength and conditioning coaches.

National Collegiate Athletic Association Athletic Trainers’, Head Coaches’, and Student-Athletes’ Perceptions of Professional Titles Used in Sport PsychologyA

The purpose of this convergent mixed-methods study was to explore National Collegiate Athletic Association (NCAA) Division I athletic trainer (AT), head coach, and student-athlete perceptions of three commonly used sport psychology professional titles in the United States: Certified Mental Performance Consultant (CMPC), mental conditioning coach, and sport psychologist. Participants included 73 ATs, 79 head coaches, and 76 student-athletes. Participants completed an online questionnaire that assessed their previous exposure to these professionals, the services they believed these professionals could provide, their confidence in sport psychology consultation from these professionals, and their stigma tolerance of these professionals. A series of Friedman tests found that ATs and student-athletes perceived significantly more confidence in the services of a sport psychologist compared to a CMPC and a mental conditioning coach. A series of Kruskal-Wallis tests revealed that student-athletes perceived significantly more stigma in using services from all three professionals than head coaches and ATs. Participants reported that sport psychologists could provide mental performance and mental health services, while CMPCs and mental conditioning coaches primarily provided mental performance services. However, short answer responses from many ATs and head coaches about CMPCs demonstrated some doubt and misunderstanding of this professional title.

Estimating Repetitions in Reserve During the Bench Press Exercise: Should We Consider Sex and the Exercise Equipment?

Estimating repetitions in reserve (RIR) has been established as a valid and practical method for monitoring set configuration concerning proximity to failure in resistance training. However, factors such as sex and exercise equipment could interfere with the estimation process. Therefore, this study aimed to determine the influence of sex (female vs male) and exercise equipment (free-weight vs Smith machine) on the RIR estimation at different relative loads during the bench press exercise. Men would be more accurate than women in the RIR estimation, and participants would better perceive their actual effort at the Smith machine compared with the free-weight bench press exercise. Repeated measures design. Level 3. In a counterbalanced order, recreationally trained participants (12 female, 14 male) performed 2 identical sessions with the free-weight bench press exercise in 1 week and 2 identical sessions with the Smith machine bench press exercise in another week (first session for familiarization and second session for validity analysis). In each session, participants performed single sets of repetitions to failure against 3 relative loads (65%, 75%, and 85% of the 1-repetition maximum [1RM]). Results revealed a significant interaction between RIR and sex at 65% 1RM (P < 0.01; women: -1.2 [-1.7 to -0.6] repetitions; men: -0.1 [-0.6 to 0.3] repetitions), and between RIR and exercise equipment at 65% 1RM (P < 0.01; free-weight: -1.1 [-1.5 to -0.6] repetitions; Smith machine: -0.2 [-0.6 to 0.2] repetitions), but not at 75% and 85% 1RM. RIR estimation is a valid method for monitoring set configuration. However, this method tends to underestimate RIR at 65%1RM with female athletes and in the free-weight exercise for both sexes. Strength and conditioning coaches should help their athletes understand effort awareness in the aforementioned context.

Position-Specific Differences in Speed Profiles Among National Football League Scouting Combine Participants.

Gillen, ZM. Position-specific differences in speed profiles among NFL scouting combine participants. J Strength Cond Res XX(X): 000-000, 2024-This study examined the relationships between speed profiles and athletic performance measurements from the National Football League (NFL) Scouting Combine, and position-specific differences in speed profiles. Subjects included NFL Scouting Combines participants with valid scores for the 40-yard dash, as well as the 10- and 20-yard splits of the 40-yard dash (n = 2,156). Subjects were divided into the following position groups: defensive backs (DBs, n = 421), defensive linemen (DL, n = 356), linebackers (LBs, n = 261), offensive linemen (OL, n = 354), running backs (RBs, n = 217), tight ends (TEs, n = 122), quarterbacks (QBs, n = 108), and wide receivers (WRs, n = 317). Performance measures included 40-yard dash time (with 10- and 20-yard split times), bench press repetitions to failure, vertical jump height, broad jump distance, pro-agility time, and L-cone drill time. The 40-yard dash and its splits calculated vmax, τ, and amax to reflect speed profiles. One-way analysis of variances examined position-related differences. Pearson's product moment correlation coefficients examined relationships between performance measures and speed profile variables. Skill positions (DB and WR) had the greatest vmax and amax, and lowest τ, followed by big skill positions (LB, RB, TE, QB), followed by DL, then OL with the lowest vmax and amax, and highest τ. For skill and big skill positions, vmax, τ, and amax exhibited greater relationships with combine measures, whereas OL generally had the lowest relationships. The position-specific differences in this study demonstrate potential areas of strength and weakness for certain positions. This may help guide strength and conditioning coaches desiring to improve position-specific speed and acceleration capabilities for American football players.

Self-Regulated Learning Assessment in Young Soccer Players: Beyond Competitive Levels.

Trecroci, A, Cavaggioni, L, Rossi, A, Bongiovanni, T, Invernizzi, PL, Formenti, D, and Longo, S. Self-regulated learning assessment in young soccer players: beyond competitive levels. J Strength Cond Res XX(X): 000-000, 2024-This study explores self-regulated learning (SRL) among young soccer players, transcending the traditional focus on competitive levels. One hundred twenty-four soccer players of regional and provincial levels from under 14 to under 17 age groups voluntarily participated in the study and were combined into a single group. A median-split method based on total time performance was used to separate players into low performers (LPs) and high performers (HPs) from a 90° change of direction dribbling test. The self-regulation of learning-self-report scale for sport practice (SRL-SRS-SP) with a 5-factor solution (planning, reflection, effort, self-efficacy, and self-supervision) and 31 items was used. The score was based on a 1-5 Likert scale. The level of significance was set at p -value < 0.05. The SRL-SRS-SP total score by HP players differed significantly from that of LP players ( p = 0.015). Regarding each subscale, HP players showed significantly higher scores than LP players ( p = 0.011) for planning, whereas no differences were observed for the remaining factors ( p ≥ 0.05). The main observation of this study revealed that HP soccer players had a greater level of engagement in the learning process with a remarkable ability to plan for specific improvement than LP peers. This suggests that the competitive level might not be the sole determinant of differences in SRL. Therefore, strength and conditioning coaches should emphasize metacognitive and motivational components because of their crucial role in enhancing technical and physical performance.

First person – Daniel Lenthall

ABSTRACT First Person is a series of interviews with the first authors of a selection of papers published in Biology Open, helping researchers promote themselves alongside their papers. Daniel Lenthall is first author on ‘ Lower-limb coordination changes following a 6-week training intervention that elicited enhancements to maximum velocity sprint performance’, published in BiO. Daniel is a Master's in Research student at Leeds Beckett University, and strength and conditioning coach in the lab of Mr Andreas Wallbaum at the University of Bath, Bath, UK, investigating research that bridges the gap between theory and practice, making a meaningful impact beyond academia.

A Virtual Functional Medicine-Based Interdisciplinary and Integrative Intervention for Gulf War Illness.

The War-Related Illness and Injury Study Center at the VA New Jersey Health Care System (WRIISC-VANJ) serves as one of the three tertiary referral centers for combat deployed Veterans of all eras with medically unexplained or difficult-to-diagnose conditions that may be related to deployment-related exposures. Many of the Veterans seen at the WRIISC experience chronic multisymptom illness (CMI), also known as Gulf War Illness (GWI). Given the complexity and interconnectedness of symptoms, Veterans with GWI are often unlikely to produce meaningful results when addressing single symptoms. Further, Veterans with GWI often have co-morbid cognitive and behavioral health conditions (e.g., TBI, PTSD, Depression), which further compromise their self-efficacy in following treatment recommendations. Thus, the WRIISC-NJ, in collaboration with Wellness Solutions Group, developed a virtual Functional Medicine-based Interdisciplinary and Integrative Intervention to improve the health of Veterans by assisting them in implementing lifestyle changes. The 6-month telehealth program included functional medicine assessments, nutrition and adaptive exercise coaching, mindfulness meditation and yoga, guest health lectures, character strength coaching, and targeted nutritional supplements. Aspects of the program were tailored to the unique clinical needs of each Veteran. Participants completed baseline and 6 month follow-up assessments of physical and emotional symptoms and overall functioning. Follow-up scores were compared with baseline data. The program was well received by Veterans with attendance across all offered sessions ranging from 70 to 100%. Further, at the end of the clinical pilot program, improvements were demonstrated in physical and mental health symptoms, intentional weight loss/gain, functional movement, and sleep quality. These preliminary results demonstrate the possibility of creating positive health outcomes across multiple health indicators in medically complex combat-deployed Veterans. Our early success and participant enthusiasm for this clinical pilot program also illustrate an opportunity to provide individualized, innovative solutions for the evaluation and treatment of Veterans with GWI.

Enhancing athletic performance with complex contrast training: A Delphi study of elite strength and conditioning coaches

This Delphi study identifies how elite strength and conditioning coaches prescribe complex contrast training to team sport athletes. Thirty-eight elite strength and conditioning coaches with experience working in high performance settings participated in a three-round survey. Round one was used to collect open-ended responses regarding the programming of complex contrast training. Responses were formulated into statements for rounds two and three, where participants rated their level of agreement using a 9-point Likert scale (agreement threshold ≥80%). In round one, 139 statements were formulated. Twenty-seven statements reached consensus in round two, and four more in round three. Based upon consensus, complex contrast training is best used during the season and dedicated power blocks. It was recommended that strength and power exercises within complex contrast training pairings be performed for 3–4 sets of 3–4 repetitions. Loading of 85–90% of one repetition maximum (1RM) was recommended for strength exercises, with ∼two repetitions in reserve, and BW–30% 1RM for power exercises, with three minutes of rest between contrast sets. Upper body pressing, upper body throwing, lower body squatting and hinging, and lower body jumping and bounding exercises were recommended. Coaches reported using complex contrast training to enhance power-focused training, and because it is more time efficient. Complex contrast training may be a time efficient method of improving athletic performance when training time is limited. Results from this study can guide the development of complex contrast training programs for team-sport athletes, and provides valuable insight into how elite coaches enhance performance.

Acute effect of injury-prevention-exercise-based warm-up vs. small-sided-game-based warm-up on speed performance in young amateur soccer players

Purpose: This study aimed to investigate the effects of an Injury-Prevention-Exercise (IPE)-based warm-up and a Small-Sided-Game (SSG)-based warm-up on subsequent speed performance in young soccer players. Method: Twelve male soccer players from the fourth division regional league in Algeria participated in the study. The participants completed both the IPE-based warm-up and the SSG-based warm-up in a counterbalanced order with a one-week interval between conditions. Linear and curved sprint performances, and change of direction (COD) speed, were assessed. Results: The results showed no significant differences between the two warm-up protocols in linear sprint performance (10m and 20m tests) or COD speed (zigzag test) (p &gt; .05). However, in curved sprinting, the IPE-based warm-up demonstrated a significant improvement in the 8.5m curve sprint on the right side (p = .017, ES = -1.04). No significant differences were observed in the other curved sprint variables (17m on both sides and 8.5m on the left side). Conclusion: the findings suggest that the IPE-based warm-up may enhance speed performance in curved sprints. However, both warm-up protocols had similar effects on linear sprint performance and COD speed. Coaches and Strength and conditioning coaches should consider incorporating neuromuscular exercises in warm-ups to optimize curved sprint performance in young soccer players.

Characterization of Health and Safety Resources for Athletes With Sickle Cell Trait at NCAA Institutions.

Yeargin, SW, Meyer, CM, Hirschhorn, RM, Lane, AD, Arent, SM, and Haggard, CR. Characterization of health and safety resources for athletes with sickle cell trait at NCAA institutions. J Strength Cond Res XX(X): 000-000, 2024-The purpose of this study was to report the prevalence of student-athletes with sickle cell trait (SCT), determine which screening practices are most commonly used, describe the health and human performance services provided to athletes, and ascertain if differences between National Collegiate Athletic Association (NCAA) designations or divisions exist. A cross-sectional survey design was used to query healthcare administrators regarding SCT resources at their institution. The independent variables were designation (historically Black colleges or universities [HBCUs] or non-HBCU) and Division (DI, DII, and DIII). The dependent variables were SCT prevalence, and the health and human performance services provided to athletes. Of the 60 respondents, HBCU ( n = 16) reported 4.9 ± 2.7% of athletes with SCT, which was higher than non-HBCU (1.1 ± 0.8%; p = 0.022). Historically Black colleges or university reported a higher percentage of student-athletes supplying their own screening results than non-HBCU (52.5 ± 39.2 vs. 12.9 ± 24.0%; p = 0.022). Division III reported higher proportions of waivers than DI (68.3 ± 38.4 vs. 16.9 ± 31.0%; p = 0.010). Most schools ( n = 42, 70.0%) reported having policy and procedures regarding exertional sickling, but none ( n = 60, 100.0%) involved strength and conditioning coaches (SCCs) during development. Practically, a greater proportion of DII and DIII institutions do not have supplemental oxygen available compared with DI but not statistically ( p = 0.058). Pragmatically, the prevalence should be considered when ordering and preparing resources annually. NCAA institutions need to create policy and procedure sections beyond screening. Athletic trainers and SCCs need to have a strong collaborative relationship to optimize health and human performance services.

“Male athletes play well to feel good, and female athletes feel good to play well”: Attitudes, beliefs, and practices pertaining to perceived sex-related differences in communication and interpersonal approach of strength and conditioning coaches in international women’s rugby union

ABSTRACT Effective communication and rapport building with athletes are key tenets of coaching. As the majority of empirical evidence to date has adopted an androcentric view of strength and conditioning, a potential knowledge gap exists regarding sex-related differences in physical preparation and coaching approaches. Therefore, this study explored the attitudes, beliefs and practices of strength and conditioning coaches (n = 8; M/F, 6/2) in elite level (international) women’s rugby union using semi-structured interviews (mean ±standard deviation duration 59 ± 15 min). The interviews explored differences in coaching practices for elite female rugby players compared to males, with a specific focus on the interpersonal aspects of the athlete-coach relationship. Reflexive thematic analysis was used to generate a rich qualitative dataset. The analysis resulted in the identification of higher order themes: athlete engagement, and interpersonal approach. The coaches in this study consistently perceived important differences between male and female players in factors related to engagement and interpersonal approach. Coaches adopted differing coaching practices for male and female athletes. This study provides important contextual evidence for the understanding of differences in the interpersonal relationships of female rugby players compared to male athletes from the perspective of elite-level strength coaches.

Countermovement Jump and Momentum Generation Associations to Fastball Velocity Performance Among Division I Collegiate Pitchers.

Sakurai, M, Qiao, M, Szymanski, DJ, and Crotin, RL. Countermovement jump and momentum generation associations to fastball velocity performance among Division I collegiate pitchers. J Strength Cond Res 38(7): 1288-1294, 2024-The current study explored the relationships between countermovement jump (CMJ) profiles and baseball pitching performance. Nineteen Division I collegiate pitchers performed in-laboratory pitching and bilateral CMJs. Whole-body kinematics and ground reaction force were collected during both pitching and CMJ evaluations. Statistically significant correlations of concentric impulse and peak power in the CMJ test with fastball velocity were observed (r = 0.71 and 0.68). Concentric impulse in CMJ also showed a statistically significant correlation with linear momentum in the anterior-posterior direction during pitching (r = 0.68). Lean body mass and body mass showed statistically significant correlations with both of the 2 linear momentums during pitching (r = 0.71∼0.83), and concentric impulse in CMJ (r = 0.71 and 0.81). Pelvis and trunk pitching mechanics did not correlate with any of the CMJ variables at the statistically significant level, whereas the direction of the correlations varied (|r| < 0.45). Assessment of a baseball pitcher's CMJ should focus on concentric impulse and peak power because only these showed meaningful relationships with fastball velocity or momentum generation during pitching. An increase in lean body mass is also suggested to be able to generate more impulse and momentum. Baseball coaches, strength coaches, and clinicians are encouraged to include lower-body explosive training to enhance the force and power output capacity of baseball pitchers.

Sports nutrition through the lens of the strength &amp; conditioning coach

Sports nutrition through the lens of the strength &amp; conditioning coach

The Effect of Lifting Straps Use on Isometric Mid-Thigh Pull Strength Performance

This study investigated the effect of lifting strap usage on isometric mid-thigh pull performance. The study was conducted on 20 healthy males with a mean age (mean ± standard deviation) of 20.8 ± 1.5 years and mean height and weight of 177.2 ± 1.6 cm and 73.8 ± 2.9 kg, respectively. Isometric mid-thigh pull performance was measured using a back leg dynamometer. The results of this study indicate that the use of lifting straps led to an increase in isometric mid-thigh pull performance (p=0.001). Overall, the use of lifting straps was effective in enhancing isometric mid-thigh pull performance. In conclusion, the use of lifting straps significantly enhances pulling performance in exercise models, such as deadlifts and mid-thigh pulls, primarily by improving the grip on the bar, compensating for low grip strength, and alleviating fatigue in the gripping muscles. Strength and conditioning coaches may play a significant role in improving athletes' 1RM performance by incorporating the use of lifting straps, especially in pulling exercises involving high weights, according to athletes' training goals.

Locomotor and Physiological Demands of Small-Sided Soccer Games in Wildcard and Regular Players: Effects of Goalkeepers and Type of Wildcard.

Small-sided games (SSGs) are frequent training drills in soccer. This study investigated whether type of game (ie, with/without goalkeepers) and wildcard ( without vs internal vs external wildcard) impact the physiological (heartrate [HR]) and locomotor (total distance [TD] covered) demands in regular and wildcard players and to evaluate between-player and within-player variability. Demands are influenced by wildcard and game type, with higher demand (distance covered at high intensities and sprint speed) in regular players and with higher variability in SSG with wildcard players. Descriptive/comparative study. Level 4. Twenty-four soccer players completed 6 SSG as 3 versus 3 without (NG) or with (GK) goalkeepers, and with internal (NG+IW and GK+IW) and external (NG+EW and GK+EW) wildcard. Average HR (HRavg), rate of perceived exertion, and locomotor demands (TD, medium [MID = 7.0-13.9 km h-1], high [HID = 14.0-20.9 km h-1] and sprint [SPD >21.0 km h-1] distance and peak speed [PS]) were registered. The inclusion of GK and internal wildcard led to decreased HRavg and TD in regular players. Wildcard players positioned internally exhibited higher TD, PS, and lower HRavg than externally positioned wildcards. Regular players demonstrated higher TD, PS, MID, HID, HRavg and time spent in Z3 (>90% HRmax) compared with wildcard players in SSG played with external wildcard. Regular and wildcard players displayed great between- and within-player variability in high-intensity metrics. Specific game type and wildcard inclusion impact the physiological and locomotor demands in SSG, with variations observed between regular and wildcard players. This study provides comprehensive information on the physiological and locomotor demands of SSG depending on the inclusion and position of goalkeepers and wildcards, which can be useful for strength and conditioning coaches when designing specific training tasks, individualizing training load and applying return-to-play programs.

Effects of Sprint Interval Training Surface on Physical Fitness Attributes of Collegiate Female Soccer Players: Identifying Individual Responses to Training on Grass, Sand, and Land Surfaces.

This study aimed to identify the optimal surface for sprint interval training to maximize transfer effects on physical performance measures on the grass pitch. Using a randomized controlled trial design, 40 collegiate female soccer players were equally assigned to three experimental groups performing short sprint interval training (SSIT: 4 sets of 10 repetitions with 5 seconds all-out running, with a 50-second recovery period between each effort and a 3-minute rest interval between sets) on SAND, GRASS, LAND, and a control group. Before and after a 7-week training period, participants underwent a series of field-based tests to evaluate countermovement jump (CMJ), 20-m linear sprint, Illinois change of direction (CoD) speed, Yo-Yo IR1, 2.4 km time trial, and maximal kicking distance (MKD) performance. A two-way analysis of variance with repeated measures was conducted on the data, along with Bonferroni post hoc testing. After the intervention, the control group did not show any changes, while the SAND, GRASS and LAND training groups demonstrated improvements (p = 0.001) in their performance as follows: CMJ (effect size [ES] = 1.21, 0.97, 0.64), 20-m linear sprint (ES = -0.81, -0.55, -0.41), Illinois CoD (ES = -0.72, -0.79, -0.41), Yo-Yo IR1 (ES = 1.86, 1.19, 1.12), 2.4 km time trail (ES = -0.82, -0.62, -0.49), and MKD (ES = 0.60, 0.90, 0.72), respectively. Comparative analysis of SAND, GRASS, and LAND revealed that performing SSIT on SAND results in a significantly greater gain in CMJ than LAND (p = 0.041). Analyzing individual responses to training interventions indicated that the training surface had a favorable influence on CMJ (SAND vs. LAND, p = 0.009), but on other variables no statistically significant (p > 0.05) differences were observed. Considering these findings, it is advised that strength and conditioning coaches use the SAND surface as the initial choice for SSIT sessions regarding greater gains (i.e., ES) in performance. This recommendation aims to facilitate more favorable transfer in physical fitness adaptation on a soccer grass pitch. In case of unavailability of SAND surface, GRASS surface would be a suitable alternative to enhance the physical fitness of collegiate female soccer players.

Comparative Analysis of Adaptive Changes in Immunoendocrine and Physiological Responses to High-Intensity Sprint Interval Training with Progressive and Nonprogressive Loads in Young Wrestlers.

The objective of this study was to explore the effects of a 7-week short sprint interval training (SSIT) with differing in programming volume-loads including progressive (P-SSIT) and nonprogressive (NP-SSIT) approaches on the immunoendocrine, physical fitness attributes and physiological parameters in male wrestlers during the pre-season. Thirty young freestyle wrestlers at the collegiate national-level were included in the study and were divided into three groups: P-SSIT (n = 10), NP-SSIT (n = 10), and an active control group (n = 10). The wrestlers engaged in their specific wrestling training three days weekly, while the P-SSIT and NP-SSIT groups underwent a 7-week SSIT, with scheduling in either progressed or nonprogressed volume-based overloads, three times per week. Before and after the intervention, various aspects of physical fitness (such as 20-m sprint, 4×9-m shuttle run, and maximal strength) and physiological parameters (including cardiorespiratory fitness and anaerobic power output), as well as immunoendocrine responses (such as immunoglobulin-A, testosterone, and cortisol) were measured. Following the training intervention, the control group did not show any significant changes in the variable measured; however, both the P-SSIT and NP-SSIT groups experienced significant improvements (p = 0.001) in physical fitness attributes and physiological parameters with effect sizes ranging from small to very large, and also more adaptive responses compared with control group (p < 0.05). In addition, there were no statistically significant changes observed among the P-SSIT and NP-SSIT groups in terms of immunoendocrine response to training, and physical fitness, as well as physiological parameters (p > 0.05). In conclusion, neither the progressed nor nonprogressed approaches of SSIT demonstrated superior effects on adaptations compared to one another. Therefore, it is recommended for strength and conditioning coaches in wrestling to incorporate both P-SSIT and NP-SSIT into their annual training plan, especially during the pre-season phase, to maximize the physical fitness and physiological parameters of their wrestlers while minimizing changes in immunoendocrine responses.