Training, psychometric status, biological markers and neuromuscular fatigue in soccer.

The study examined the relationship between psychometric status, neuromuscular, and biochemical markers of fatigue in response to an intensified training (IT) period in soccer. Fifteen professional soccer players volunteered to participate in the study (mean ± SD: age: 25 ± 1 years; body height: 179 ± 7 cm, body mass: 73.7 ± 16.2 kg, experience: 13.2 ± 3 years). Training load, monotony, strain, Hooper index and total quality recovery (TQR) were determined for each training session during a 2-week of IT. Counter-movement jump (CMJ) and biochemical responses [testosterone, cortisol, testosterone-to-cortisol ratio (T/C ratio), creatine kinase, and C-reactive protein] were collected before and after IT. Results showed that IT induced significant increases in cortisol, creatine kinase and C-reactive protein and significant decreases in T/C ratio and CMJ performance from before to after IT (p < 0.01, p < 0.001, p < 0.001, p < 0.01, p < 0.05, respectively). However, testosterone did not differ from before to after IT (p > 0.05). Training loads were positively correlated with Hooper index (p < 0.05) and negatively correlated with total quality recovery (p < 0.05). Hooper index was positively correlated with cortisol (p < 0.05), T/C ratio (p < 0.01), and creatine kinase (p < 0.01), and negatively correlated with CMJ (p < 0.05). Furthermore, TQR was negatively correlated with T/C ratio (p < 0.01), creatine kinase (p < 0.001), and C-reactive protein (p < 0.05), and positively correlated with CMJ (p < 0.01). Neuromuscular fatigue, muscle damage, and change in the anabolic/catabolic state induced by the IT were related to well-being and perceived recovery state among professional soccer players.

Effects of 1 vs. 2 sessions per week of equal-volume sprint training on explosive, high-intensity and endurance-intensive performances in young soccer players.

The study aimed to evaluate the effects of 1 vs. 2 sessions per week of equal-volume sprint training on explosive, high-intensity and endurance-intensive performances among young soccer players. Thirty-six young male soccer players were randomly divided into 2 experimental groups that performed either a single weekly sprint training session (ST1, n = 18, age: 17.2 ± 0.8 years) or two weekly sprint training sessions (ST2, n = 18; age: 17.1 ± 0.9 years) of equal weekly and total volume, in addition to their regular soccer training regimen. Linear sprinting (10 m, 20 m, 30 m, and flying 10 m), T-test agility, countermovement jump (CMJ) and maximal oxygen consumption were assessed one week before (T1), in the middle (T2) and immediately after the 10 weeks of training (T3). A large magnitude and statistically significant main effect for time was found in all the assessed variables after both training interventions (all p < 0.001; ES ≥ 0.80). No main effect was observed between the 2 groups at any time in linear sprinting, T-test or CMJ test (p > 0.05; ES < 0.20). A significant interaction effect (F = 4.05; p = 0.04, ES = 0.21) was found for maximal oxygen consumption with ST2 inducing better performance than ST1 (p = 0.001; ES = 1.11). Our findings suggested that the two sprint training frequencies were effective in enhancing explosive, high-intensity and endurance-intensive performances. However, it is recommended for coaches and fitness coaches to use a biweekly sprint training modality as it was found to be more effective in improving endurance-intensive performance.

Influence of intense training cycle and psychometric status on technical and physiological aspects performed during the small-sided games in soccer players.

The study investigated the effect of intense training cycle (IT) of early season preparation period (SPP) and psychological status on technical and physiological parameters during small-sided games (SSG) and the relationships between these variables. Sixteen professional soccer players participated in the study (mean±SD: age: 24.5±4.1). Training load (TL), Total quality recovery (TQR) and well-being indices were performed daily. TL increased progressively (%TL=31.56 [AU]). Physiological variables did not change after IT and were not influenced by well-being indices and TQR. Technical aspects were negatively altered after IT (p<0.05). TL was significantly correlated with successful passes (r=-0.57, p=0.02), interceptions (r=-0.83, p<0.001) and lost balls (r=0.73, p=0.002). Well-being and TQR were related to successful passes, interceptions and lost passes [(r=-0.55, p=0.03; r=-0.75, p=0.001; r=-0.69, p=0.004); (r=0.54, p=0.03; r=-0.76, p=0.001; r=-0.69, p=0.004), respectively]. TL, Well-being indices and TQR represent a useful strategy for coaches to control technical aspects in soccer players during SPP.

Physiological Responses and Time-Motion Analysis of Small Combat Games in Kickboxing: Impact of Ring Size and Number of Within-Round Sparring Partners.

Ouergui, I, Houcine, N, Marzouki, H, Davis, P, Franchini, E, Gmada, N, and Bouhlel, E. Physiological responses and time-motion analysis of small combat games in kickboxing: impact of ring size and number of within-round sparring partners. J Strength Cond Res 31(7): 1840-1846, 2017-The study aimed to investigate the physiological responses and time-structure of small combat games (SCGs) in kickboxing according to ring sizes and number of sparring partners. Twenty athletes from regional (n = 13) and national levels (n = 7) participated in the study (mean ± SD, age: 20.3 ± 0.9 years; height: 177 ± 4.8 cm; body mass: 71.8 ± 10.5 kg). Blood lactate concentration [La] was measured before and after bouts, and the delta (Δ) was determined. Heart rate (HR) was measured throughout and HR and rating of perceived exertion (RPE) were also measured postbout. The HRpre, HRmean, and percentage of peak HR (%HRpeak) were used for analysis. The HRpeak was determined during a cycle ergometer graded exercise test. Each athlete was confronted by 1 (1 vs. 1; no sparring partner change), 2 (1 vs. 2) and 4 opponents (1 vs. 4) within-round (sparring partner change every 1 minute or 30 seconds, respectively) in different ring sizes (i.e., 2×2 m, 4×4 m, and 6×6 m). All combats were recorded and analyzed to determine the duration of different activity phases (high-intensity activities [HIA], low-intensity actions [LIA], and referee pause [P]). Results showed that values for HRpre and HRmean when opposed by a single individual (1 vs. 1) were lower than other conditions (all p < 0.001). Moreover, %HRpeak values in 1 vs. 1 were lower than in other conditions and higher in 4 × 4 m compared with other sizes. [La]pre, post, and the Δ did not differ among all conditions (p > 0.05). The RPE scores were lower in 1 vs. 1 compared with other conditions (p < 0.001), with no ring sizes effect (p > 0.05). For time-motion variables, HIA values were lower in 1 vs. 1 than in the 2 other conditions and was longer in 2 × 2 m compared with 4 × 4 m and 6 × 6 m, whereas LIA values were higher in 1 vs. 1 and lower in the 2 × 2 m. In conclusion, SCGs seem to be a good form of exercise for sufficient cardiovascular conditioning specific to kickboxing activity in comparison with data from previous studies.

Development of a Noncontact Kickboxing Circuit Training Protocol That Simulates Elite Male Kickboxing Competition.

The aim of this study was to verify whether the specific kickboxing circuit training protocol (SKCTP) could reproduce kickboxing combat's hormonal, physiological, and physical responses. Twenty athletes of regional and national level volunteered to participate in the study (mean ± SD, age: 21.3 ± 2.7 years; height: 170 ± 0.5 cm; body mass: 73.9 ± 13.9 kg). After familiarization, SKCTP was conducted 1 week before a kickboxing competition. Cortisol, testosterone, growth hormone (GH), blood lactate [La], and glucose concentrations, as well as the Wingate upper-body test and countermovement jump (CMJ) performances were measured before and after SKCTP and combat. Heart rate (HR) and rating of perceived exertion (RPE) were measured throughout rounds (R) R1, R2, and R3. Testosterone, GH, glucose, [La], HR, RPE, and CMJ did not differ among the 2 conditions (p > 0.05). However, Cortisol was higher for competition (p = 0.038), whereas both peak (p = 0.003) and mean power (p < 0.001) were higher in SKCTP. The study suggests that SKCTP replicates the hormonal, physiological, and physical aspects of competition. It is therefore suggested as a good form of specific kickboxing training, as well as a specific assessment tool to be used by kickboxing coaches to quantify kickboxers' fitness levels, when physiological parameters responses to the test are measured.

Effects of Biological Age on Athletic Adaptations to Combined Plyometric and Sprint with Change of Direction with Ball Training in Youth Soccer Players.

There is evidence for the effectiveness of youth combined plyometric and sprint with change of direction (COD) training. However, the evidence is not well-known regarding the in-season effects of biological age (peak height velocity­PHV) on the motor adaptive processes following combined plyometric and COD with ball training (P-CODBT) in youth soccer players. This study aimed to examine the in-season effects of P-CODBT (8 weeks and twice a week) on the athletic performances of male youth soccer players, circa- and post-PHV. In a randomized controlled training study with pre-to-post measurements, forty-eight male players were assigned into two experimental (performing P-CODBT; n = 12 × circa-PHV and n = 12 × post-PHV) and two control groups (CONG; n = 12 × circa-PHV and n = 12 × post-PHV). The pre- and post-training participants were assessed for their anthropometric, linear sprinting with and without a ball, COD speed with and without a ball, vertical jump, dynamic balance, and endurance-intensive performances. After the intervention, the experimental condition induced significant (all p < 0.0001) and small to large effect size (ES = 0.263−3.471) additional gains only on explosive measures compared to CONG. Both the experimental (all p < 0.0001; ES = 0.338−1.908) and control (p = 0.011−0.0001; ES = 0.2−1.8) groups improved their athletic performances over the training period. The improvements generated by p-CODBT were not affected by biological age. In-season short-term P-CODBT (twice a week) could be safe way to generate benefits in explosive performances in youth soccer players, which are relevant components of match-winning actions in soccer.

Effects of Aquatic Training in Children with Autism Spectrum Disorder.

A variety of aquatic training regimens have been found to be beneficial for individuals with autism spectrum disorders (ASD) in multiple domains. This study investigated and compared the efficacy of two aquatic training regimens (technical vs. game-based) on gross motor skills, stereotypy behavior and emotion regulation in children with ASD. Twenty-two autistic children were randomly assigned into three groups: two experimental groups performed either a technical aquatic program or a game-based aquatic program and a control group. Participants were assessed before and after an 8-week training period, with the Test of Gross Motor Development, the stereotypy subscale of the Gilliam Autism Rating Scale, and the Emotion Regulation Checklist. A significant effect for time was found in gross motor skills and stereotypy behavior in both experimental groups. An improvement in gross motor skills was observed in both experimental groups compared to the control group. A small pre-post change effect in emotion functioning was found in all groups. No significant differences were observed between the experimental groups in all assessed variables. Our findings provide additional evidence suggesting the effectiveness of beneficial effects of aquatic activities on the motor and social skills that underpin the hypothesis that motor and intellectual domains are highly interrelated in autistic children.

Effects of Surface-Type Plyometric Training on Physical Fitness in Schoolchildren of Both Sexes: A Randomized Controlled Intervention.

Plyometric training (PT) has been found to be effective for children's fitness. However, no study has examined the effects of sex on physical fitness adaptations from surface-type PT in children. This study compared the effects of short-term surface-type PT (firm vs. sand) on the physical fitness of schoolchildren of both sexes. Sixty girls (age = 10.00 ± 1.15 years) and sixty boys (age = 10.02 ± 1.12 years) participated in a short-term (4 weeks), randomized and parallel PT design with pre-to-post measurements. Children were divided into two experimental groups (firm group: PT performed on a clay surface, 20 boys and 20 girls; sand group: PT performed on a dry surface of 20 cm deep sand, 20 boys and 20 girls) and a control group (CG, 20 boys and 20 girls). Squat jump, standing long jump, 20 m sprint, 5-10-5 shuttle, dynamic balance, and maximal aerobic velocity were measured at baseline and after intervention. Both experimental groups showed greater pre-post changes in all assessed variables than the CG (p < 0.0001). No significant differences in pre-post changes were observed relative to surface type or sex (p > 0.05). These findings suggest that a twice-weekly PT program induced physical fitness improvements, which may have transfer to health status during childhood. Additionally, surface type and sex did not affect the training-induced changes in physical fitness.

Effects of Four Weeks of Plyometric Training Performed in Different Training Surfaces on Physical Performances in School Children: Age and Sex Comparisons.

Short- to middle-term plyometric training has been shown to be an effective method to promote youth fitness and health. However, there is no knowledge of previous studies that investigated the sex and age effects on physical fitness following different PT surfaces (i.e., firm vs. sand) in schoolchildren. This study examined the effects of age and sex on explosive and high-intensity responses following plyometric training (4 weeks, twice/week) performed on firm vs. sand surfaces in untrained schoolchildren. Ninety girls and ninety boys (under 8: age = 7.1 ± 0.5 and 7.1 ± 0.4 years; under 10: age = 9.0 ± 0.4 and 9.0 ± 0.5 years; under 12: age = 11.0 ± 0.5 and 11.0 ± 0.5 years, respectively) participated in a randomized and parallel training design with pre-to-post testing. Participants were allocated (i.e., 30 boys and 30 girls for each group) into either two experimental groups (firm group: performing plyometrics on a clay surface and sand group: performing plyometrics on a dry surface of 20 cm deep sand) or a control group (CG, habitual physical education classes) within their corresponding age groups. Children were tested for sprint, jumping and change of direction speed performances before and after 4 weeks of plyometric training. Both experimental groups induced more significant improvements in all assessed variables than CG (p < 0.0001; effect size > 0.80), whereas both surfaces induced similar improvements (p > 0.05). Older boys achieved better performances than their younger counterparts (p < 0.05) and older girls (p < 0.0001), respectively. This finding showed that age and sex could affect explosive and high-intensity performances during childhood after a short-term plyometric training. In contrast, the training-induced fitness changes were not influenced by the type of surface.

Hormonal, Physiological, and Physical Performance During Simulated Kickboxing Combat: Differences Between Winners and Losers.

The aim of the current study was to investigate the hormonal, physiological, and physical responses of simulated kickboxing competition and evaluate if there was a difference between winners and losers. Twenty athletes of regional and national level participated in the study (mean ± SD age 21.3 ± 2.7 y, height 170.0 ± 5.0 cm). Hormone (cortisol, testosterone, growth hormone), blood lactate [La], and glucose concentrations, as well as upper-body Wingate test and countermovement-jump (CMJ) performances, were measured before and after combats. Heart rate (HR) was measured throughout rounds 1, 2, and 3 and rating of perceived exertion (RPE) was taken after each round. All combats were recorded and analyzed to determine the length of different activity phases (high-intensity, low-intensity, and referee pause) and the frequency of techniques. Hormones, glucose, [La], HR, and RPE increased (all P < .001) precombat to postcombat, while a decrease was observed for CMJ, Wingate test performance, body mass (all P < .001), and time of high-intensity activities (P = .005). There was no difference between winners and losers for hormonal, physiological, and physical variables (P > .05). However, winners executed more jab cross, total punches, roundhouse kicks, total kicks, and total attacking techniques (all P < .042) than losers. Kickboxing is an intermittent physically demanding sport that induces changes in the stress-related hormones soliciting the anaerobic lactic system. Training should be oriented to enhance kickboxers' anaerobic lactic fitness and their ability to strike at a sufficient rate. Further investigation is needed to identify possible differences in tactical and mental abilities that offer some insight into what makes winners winners.