See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/297260122 Does intrasession concurrent strength and aerobic training order influence training- induced explosive strength and... Article in The Journal of Strength and Conditioning Research · March 2016 DOI: 10.1519/JSC.0000000000001431 CITATIONS READS 0 320 5 authors, including: Carlos Marta Henrique P. Neiva Polytechnic Institute of Guarda Universidade da Beira Interior 22 PUBLICATIONS 44 CITATIONS 35 PUBLICATIONS 66 CITATIONS SEE PROFILE SEE PROFILE Mikel Izquierdo Mário C Marques Universidad Pública de Navarra Universidade da Beira Interior 291 PUBLICATIONS 6,712 CITATIONS 198 PUBLICATIONS 1,141 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: NEW METHODOLOGICAL APPROACH TO RTD EVALUATION IN RELATION TO HAMSTRING STRAIN INJURIES IN FEMALE ATHLETES. A PRELIMINARY STUDY View project Exercise Training and Hepatic Metabolism in Overweight/Obese Adolescent (HEPAFIT) View project Available from: Mikel Izquierdo Retrieved on: 16 November 2016 Journal of Strength and Conditioning Research Publish Ahead of Print DOI: 10.1519/JSC.0 000000000001431 Does intrasession concurrent strength and aerobic training order influence training-induced explosive strength and VO in prepubescent children? 2max D Running head: Concurrent training order and explosive strength E Ana R. Alves 1, Carlos Marta 3, 4, Henrique P. Neiva1, 2, Mikel Izquierdo 5, Mário C. Marques1,2 T 1 University of Beira Interior. Department of Sport Sciences, Covilhã, Portugal 2 Research Center in Sport Sciences, Health Sciences aPnd Human Development, CIDESD, Portugal E 3 Guarda Polytechnique Institute. Department of Sport Sciences, Guarda, Portugal 4 Research Unit for Inland Development, UDI, Guarda, Portugal C 5 Department of Health Sciences, Public University of Navarre, Navarre, Spain C Corresponding Author and address: Mikel Izquierdo, PhD Department of Health Sciences A Public University of Navarra (Navarra) SPAIN Campus of Tudela Av. de Tarazona s/n. 31500 Tudela (Navarra) SPAIN Tel + 34 948 417876 [email protected] The authors disclose funding received for this work from any of the following organizations: National Institutes of Health (NIH); Welcome Trust; Howard Hughes Medical Institute (HHMI); and other(s). Copyright ª 2016 National Strength and Conditioning Association 1 ABSTRACT The aim of this study was to analyze the interference of strength and aerobic training order D over an 8-week period on explosive skills and maximal oxygen uptake (VO ) in 2max prepubescent children. One hundred and twenty-eight prepubescent children aged 10-11 E years (10.9±0.5 years) were randomly selected and assigned to one of the three groups: intrasession concurrent aerobic prior to (GAS: n=39) or after strength training (GSA: n=45) T or control group (GC: n=44; no training program). The GC maintained their baseline level performance, and training-induced differences were fPound in the experimental groups. Increases were found in the 1 kg and 3 kg medicine ball throws: GAS: +3%, +5.5%, p<0.05, E p<0.001; GSA: +5.7%, +8.7%, p<0.001, respectively; in the counter movement jump height and standing long jump length: GAS: +6.5%, +3.4%, p<0.05; GSA: +7%, +4.5%, p<0.001, C respectively; in the 20 m shuttle run time: GAS: +2.3%; GSA: +4.6%, p<0.001; and, in the VO : GAS: +7.3%, p<0.001; GSA: +3.8%, p<0.001 from pre- to post-training. All 2max C programs were effective, but GSA produced better results than GAS for muscle strength variables, and GAS produced better results than GSA for aerobic capacity variables. The A present study explored an unknown issue and added useful information to the literature in this area. These training methods should be taken into consideration to optimize explosive strength and cardiorespiratory fitness training in school-based programs and sports club programs. Key words: Youth, Power, Cardiorespiratory, Muscular Conditioning, Sequence Copyright ª 2016 National Strength and Conditioning Association 2 INTRODUCTION Concurrent training (i.e., a combination of strength and aerobic regimens) has become a recurrent topic for researchers due to the controversial results of different experiments (7, 8, D 10, 16, 23). Several studies have shown that concurrent training can affect the development of muscle strength and/or power (16, 20, 24, 29). In contrast, other experiments have E indicated a positive effect of concurrent training on strength (3, 12, 13, 18, 19, 27) and on maximal aerobic capacity (17, 28, 35, 40). T P Whereas multiple studies have investigated concurrent training in young, adult or even E elderly populations (9, 12, 22, 34, 42), a limited number of studies have explored concurrent training in prepubescent (34) and pubescent children (39). The majority of the pediatric C research has focused on activities that enhance cardiorespiratory fitness and recent findings indicate that strength traCining offer benefits to children and adolescents (15, 26, 39). Meanwhile, improvements in muscular fitness, speed and agility, rather than cardiorespiratoryA fitness, seem to have a positive effect on skeletal health (26, 39). Concurrent aerobic training and strength training have the potential to bring about gains in cardiorespiratory and muscular fitness simultaneously (25). Moreover, children and adolescents involved in physical education classes often perform strength and aerobic training concurrently in an effort to achieve specific adaptations to both forms of training (24, 39). Furthermore, Marta et al. (34), showed that concurrent training is equally effective on training-induced explosive strength as only strength training in prepubescent children. Moreover, this experiment only compared the effects of concurrent training on the same day vs. strength training alone. In fact, concurrent training order in prepubescent children is Copyright ª 2016 National Strength and Conditioning Association 3 another important issue that still has not been investigated. According to Kang and Ratamess (25), most studies suggest that different intrasession training order produces no significant differences in training-induced adaptations because both combinations generate similar improvements in cardiorespiratory and muscular fitness. Furthermore, those studies also found that either training order can have its own advantages that could make concurrent D training more effective. For example, Chtara et al. (9) observed that performing aerobic training prior to strength training could improve running performance and VO to a greater E2max extent than the reverse order. Nevertheless, Cadore et al. (6, 7) suggested that for intrasession T concurrent training protocols, the strength gains might be optimized with intrasession strength prior to aerobic training order. To the best of our knowledge, no research has been P conducted concerning the effects of intrasession concurrent strength and aerobic training order on training-induced explosive strength in prepubescent populations; thus, research in E this area seems useful and relevant. C Therefore, the purpose of Cthe current study was to analyze the interference of intrasession concurrent strength and aerobic training order over an 8-week period on explosive skills and A maximal oxygen uptake (VO ) in a large sample of prepubescent children. We 2max hypothesized that the prepubescent children would show increased explosive strength following the 8-week intrasession concurrent strength prior to aerobic training order, and that the prepubescent children would show increases VO independent of the training 2max approach. Copyright ª 2016 National Strength and Conditioning Association 4 METHODS Experimental Approach to the Problem The aim of the current study was to analyze the interference of intrasession concurrent D strength and aerobic training order (strength prior to aerobic training (GSA) or aerobic prior to strength training (GAS)) over an 8-week period on explosive strength andE maximal oxygen uptake (VO ) in prepubescent children. The study followed a repeated measures design, 2max T with each participant randomly assigned to a specific training program (concurrent strength and aerobic training or concurrent aerobic and strength training) or the control group (no P training regimen). The 8-week period and study design were developed based in specific studies conducted in prepubescent children wEhich performed in similar periods (33, 34). Based on those studies, and the knowledge of an experienced coach and researcher, a training C program composed of specific sets, repetitions and exercises was designed. The children were evaluated for changes in strength (1 and 3 kg medicine ball throw, standing long jump, C counter movement jump, and a 20 m sprint running) and cardiovascular parameters (VO ) 2max before and after 8 weeks of training. A Subjects The sample consisted of one hundred and twenty-eight healthy prepubescent children (aged 10.91 ± 0.51 years) from the Santa Clara school cluster (Guarda, Portugal) who were randomly assigned to the different training programs or the control group. The average height and body mass of the entire sample were 1.43 ± 7.53 m and 39.12 ± 8.60 kg, respectively. The inclusion criteria were children aged 10 to 12 years (in 5th or 6th grade) without a chronic Copyright ª 2016 National Strength and Conditioning Association 5 pediatric disease or orthopedic limitation and without regular extra-curricular physical activity (i.e., practice of a sport at an academy). Before data collection and the beginning of training, each participant reported any health problems, physical limitations, physical activity habits and training experiences within the D last 6 months. Thereafter, maturity level was determined based on Tanner stage (14) through self-assessment; to minimize the effects of growth, only children that were self-assessed as E Tanner stage I-II were selected. No subject had regularly participated in any training program T prior to this experiment. Efforts were made to collect participants that would form comparable groups. Prior to the start of the study, all participants and their parents/guardians P were informed about study procedures as well as possible benefits and risks. The written informed consent was obtained from parents/ guardians of all participants. The study was E approved by the Institutional Review Board of the University of Beira Interior and C procedures were in accordance with the latest version of the Declaration of Helsinki. There were no injuries resulting from the implementation of the training programs. C Procedures A Sample Procedures Children were recruited from a Portuguese public high school and randomly assigned to two experimental groups (8-week training, twice a week, from January 14 to March 15, 2015) and one control group. The groups were intrasession concurrent strength prior to aerobic training group (GSA: n=45, 24 girls, 21 boys), intrasession concurrent aerobic prior to strength training group (GAS: n= 39, 16 girls, 23 boys), and a control group (GC: n=44, 23 girls, 21 Copyright ª 2016 National Strength and Conditioning Association 6 boys) with no training protocol. This last group followed the physical education class curriculum and did not undergo a specific training program. The assigned groups were determined randomly using a random number generator on a computer and could not be predicted. This procedure was established according to the “CONSORT” statement, which can be found at http://www.consort-statement.org/. The participants were randomly assigned D to 1 of 3 intervention arms. Randomization was performed using R software version 2.14 (R Foundation for Statistical Computing, and developed by Bell Laboratories- Lucent E Technologies, in Vienna, Austria). Before the start of training, all subjects attended physical T education classes twice a week, with one class lasting 45 minutes and the other lasting 90 minutes. Typical physical education classes have low to moderate intensity and involve the P performance of various sports (team sports, gymnastics, dance, adventure sports, etc.) with an evident pedagogical focus. E C Training Procedures C The training programs were implemented in addition to the physical education classes. Prior to training, the sAubjects warmed up for approximately 10 min with low to moderate intensity exercises (e.g., running, sprints, stretching and joint specific warm-up). Joint rotations, slow circular movements in the clockwise and counter-clockwise direction, were performed until the entire joint moved smoothly. Stretching exercises, including back and chest stretches, shoulder and side stretches, and wrist, waist, quadriceps, groin, and hamstring stretches, were performed. At the end of the training sessions, all subjects performed 5 min of static stretching exercises, such as kneeling lunges, the ankle-over-knee stretch, rotation and hamstring stretches. After the warm-up period, the GSA group performed strength training and then a 20 m shuttle run exercise, while the GAS group performed a 20 m shuttle run Copyright ª 2016 National Strength and Conditioning Association 7 exercise and then strength training. The aerobic training task was based on individual training volume that was set to approximately 75% of the established maximum aerobic volume achieved on a previous test. After 4 weeks of training, both experimental groups were reassessed by a 20 m shuttle run test to readjust the volume and intensity of the 20 m shuttle run exercise. D Before the start of training, subjects completed two familiarization sessions to practice the E exercises and routines that they would perform during the training period (i.e., power training T exercises and 20 m shuttle run test). During this time, the children were taught the proper technique for each training exercise, and all of their questions were properly answered to P remove any doubts regarding the exercise techniques. During training, the safety of the children, including the maintenance of safe hydration levels, was ensured, and all children E were encouraged to do their best to achieve the best results. Clear instructions about the C importance of adequate nutrition were also delivered. The instructions for the 20 m shuttle run were given with the aid of a multi-stage fitness test audio CD of the FITNESSGRAM® C test battery. During this time, all children were taught the proper technique for each training exercise, and all of their questions were properly answered to remove any doubts regarding A the exercise techniques. Throughout the pre- and experimental periods, the subjects reported that they were not involved in regular exercise programs for developing or maintaining strength and endurance performance other than institutional regular physical education classes. A more detailed analysis of the program can be found in table 1. (Table 1 about here) Copyright ª 2016 National Strength and Conditioning Association 8 The experimental groups were assessed for upper and lower body explosive strength (ball throws 1-3 kg and jumps, respectively), running speed (20 m sprint), and VO (20 m 2max shuttle run test) before and after the 8 weeks of the training program. The testing assessment procedures were always conducted in the same indoor environment and at the same time each week. Each subject was familiarized with the power training tests (ball throws, jumps, and D sprints) and with the 20 m multistage shuttle run test. The same researcher performed the training program, anthropometric and physical fitness assessments, and data collection. E T Testing Procedures P Anthropometric Measurements. All anthropomeEtric measurements were assessed according to international standards for anthropometric assessment (32) and were obtained prior to any C physical performance test. The participants were barefoot and only wearing underwear. Body mass (in kg) was measured to the nearest 0.1 kg using a standard digital floor scale (Seca, C model 841, Germany). A precision stadiometer with a scale range of 0.001 m was used to measure body height (in m) (Seca, model 214, Germany). A Medicine Ball Throwing. This test was performed according to the protocol described by Mayhew et al. (31). The subjects were seated with the backside of their trunk touching a wall. They were required to hold medicine balls (Bhalla International - Vinex Sports, Meerut - India) that weighed 1 kg (Vinex, model VMB-001R, perimeter 0.72 m) and 3 kg (Vinex, model VMB-003R, perimeter 0.78 m) with their hands (abreast of chest) and throw the ball forward for the maximum possible distance. Neither hip inflection nor withdrawal of the trunk away from the wall was allowed. Three trials were performed. The throws were Copyright ª 2016 National Strength and Conditioning Association