Responses of soccer players performing repeated maximal efforts in simulated conditions of the FIFA World Cup Qatar 2022: A holistic approach.

This study aimed to assess the capacity for repeated maximal effort (RME) of soccer players in the thermo-natural conditions (NC) and in simulated conditions for the 2022 FIFA World Cup in Qatar (QSC). Twenty-four semi-professional soccer players participated in the study. The exercise test consisted of ten 6-second maximal efforts on a cycloergometer. A 90-second passive rest interval was used. The test was performed in a Weiss Technik WK-26 climate test chamber in two different conditions: 1) thermo-neutral conditions (NC-20.5°C; 58.7% humidity); and 2) simulated conditions for the 2022 World Cup in Qatar (QSC-28.5 ± 1.92°C; 58.7 ± 8.64% humidity). Power-related, physiological, psychomotor, blood, and electrolyte variables were recorded. Results showed that (1) players achieved higher peak power (max 1607,46 ± 192,70 [W] - 3rd rep), needed less time to peak power (min 0,95 ± 0,27 [s] - 3rd rep), and had a higher fatigue slope (max 218,67 ± 59,64 [W/sek] - 7th rep) in QSC than in NC (in each repetition of study protocol); (2) between the 1st repetition and subsequent repetitions a number of significants in among physiological, blood-related, and electrolyte variables were noted, but their direction was similar in both simulated conditions (e.g. V'O2/kg 37,59 ± 3,96 vs 37,95 ± 3,17 [ml/min/kg] - 3rd rep, LAC 13,16 ± 2,61 vs 14,18 ± 3,13 [mg/dl] - 10th rep or K 4,54 ± 0,29 vs 4,79 ± 0,36 [mmol/l] - 2nd rep when compare QCS and NC respectively); (3) an 8°C of temperature difference between the climatic conditions did not significantly affect the soccer players' physical and physiological responses in RME. The study results can be used in the design of training programs aimed to increase players' physiological adaptations by simulating soccer-specific conditions of play in terms of anaerobic capacity, in particular, repetitive maximal efforts. These findings will be useful during the upcoming 2022 World Cup in Qatar and in locations where high ambient temperatures are customary.

Branched-Chain Amino Acids Supplementation Does Not Accelerate Recovery after a Change of Direction Sprinting Exercise Protocol.

BCAAs supplementation has been widely used for post-exercise recovery. However, no evidence is currently available to answer the question of whether BCAAs supplementation can attenuate muscle damage and ameliorate recovery after a bout of change of direction (COD) sprinting, which is an exercise motion frequently used during team sport actions. This study aimed to assess the effect of BCAAs supplementation on muscle damage markers, subjective muscle soreness, neuromuscular performance, and the vascular health of collegiate basketball players during a 72 h recovery period after a standardized COD protocol. Participants orally received either BCAAs (0.17 g/kg BCAAs + 0.17 g/kg glucose) or placebo (0.34 g/kg glucose) supplementation before and immediately after a COD exercise protocol in a randomized, crossover, double-blind, and placebo-controlled manner. Creatine kinase increased immediately after exercise and peaked at 24 h, muscle soreness remained elevated until 72 h, whilst arterial stiffness decreased after exercise for both supplemented conditions. A negligibly lower level of interleukin-6 was found in the BCAAs supplemented condition. In conclusion, the results of this study do not support the benefits of BCAAs supplementation on mitigating muscle damage and soreness, neuromuscular performance, and arterial stiffness after COD for basketball players.

Salivary alpha-amylase, salivary cortisol, and anxiety during a youth taekwondo championship: An observational study.

The aim of this study was to assess the stress-related responses and the coach's capability to match perceived efforts of youth athletes during a taekwondo championship.Using a cross-sectional study design, salivary cortisol (sC) and alpha-amylase (sAA) were measured in 6 males and 3 females young (11.0 ±â€Š0.9 years) athletes at awakening, 5 minutes before, and 1 minute and 30 minutes after official combats. State anxiety was recorded 60 minutes before the first competition, whereas coach's and athletes' ratings of perceived exertion (RPE) were obtained at the end of the combats. Time-matched (awakening and pre-competition) salivary samples and trait anxiety were collected 7-day postcompetition during a resting day.No effect for match outcome emerged. No difference emerged between athletes and coach RPEs. Higher (P = .03) state anxiety (41.6 ±â€Š10.9 points) was shown than trait anxiety (34.8 ±â€Š7.1 points). Time-matched sAA were similar. Peak sAA observed at the end of the combat (114.2 ±â€Š108.1 U/mL) was higher (P < .01) than the other samples (range: 20.6-48.1 U/mL), whereas sC increased (P < .05) from awakening (8.0 ±â€Š1.5 nmol/L), with peak levels observed at 30 minutes into the recovery phase (19.3 ±â€Š4.3 nmol/L). Furthermore, pre-competition sC (16.5 ±â€Š4.5 nmol/L) values were higher (P < .01) with respect to time-matched samples during the resting day (4.6 ±â€Š1.0 nmol/L). The 3 athletes engaged in consecutive matches showed a tendency toward increasing sAA and sC.Taekwondo combats pose a high stress on young athletes, eliciting a fast reactivity of the sympathetic-adreno-medullary system relative to the hypothalamic-pituitary-adrenocortical system. Understanding the athlete's efforts during combats, coaches are recommended to apply effective recovery strategies between matches.

Session-RPE for quantifying load of different youth taekwondo training sessions.

BACKGROUND: The session rating of perceived exertion (session-RPE) proved to be a valuable method to quantify the internal training load (ITL) in taekwondo. However, no study validated this method in youth taekwondo athletes performing different training sessions. Thus this study aimed at evaluating the reliability of the session-RPE to monitor the ITL of prepubescent taekwondo athletes during pre-competitive (PC) and competitive (C) training sessions. METHODS: Five female (age: 12.0±0.7 y; height: 1.54±0.08 m; body mass: 48.8±7.3 kg) and four male (age: 12.0±0.8 yrs; height: 1.55±0.07 m; body mass: 47.3±5.3 kg) taekwondo athletes were monitored during 100 individual sessions (PC: N.=33; C: N.=67). The Edwards' HR method was used as reference measure of ITL; the CR-10 RPE scale was administered at 1- and 30-minutes from the end of each session. RESULTS: No difference for gender emerged. The ITLs of C (Edwards: 228±40 arbitrary units, AU) resulted higher than that of PC (192±26 AU; P=0.04). Although all training typologies and data collections achieved significant correlations between Edwards' and session-RPE methods, a large relationship (r =0.71, P<0.001) emerged only for PC sessions evaluated at 30 minutes of the recovery phases. CONCLUSIONS: Findings support coaches of prepubescent taekwondo athletes to successfully use session-RPE to monitor the ITL of different training typologies. However, PC training evaluated at 30 minutes of the recovery phase represents the best condition for a highly reliable ITL perception.

Technical-tactical analysis of youth olympic taekwondo combat.

The purpose of this study was to define the technical and tactical profiles of official youth taekwondo competitions played under the most recent rules of the International Taekwondo Federation. Tactical actions (i.e., attack, defense, and block), technical executions (from 1- to 4-point scores), kicking legs (i.e., front/rear and right/left), and overall technical effectiveness were investigated in relation to match outcome of semifinal and final competitions (n = 50) of youth (aged 13-14 years) black belt athletes during the Italian Taekwondo Cadet Championship. Differences (p < 0.001) were found among all action typologies (Attack: 50.9 ± 2.2%; Defense: 27.7 ± 1.5%; Block: 21.3 ± 1.6%), with winners showing fewer (p = 0.005) offensive actions and more (p = 0.001) defensive actions with respect to non-winners. Independently from match outcome, technical exchanges showed differences (p < 0.001) for technical executions. Winners resulted more efficient (p < 0.001) for both technical and tactical variables. In general, these findings showed that Cadets tend to adopt an offensive strategy. In considering that the adoption of the new electronic system requires athletes to execute correct technical actions to have a score assigned, coaches should emphasize the effectiveness of scoring techniques and help athletes to effectively improve their defense and counterattack capabilities.

Time-motion analysis of youth Olympic Taekwondo combats.

This study aimed to analyze the time-motion structure of combat phases (fighting: F, nonfighting: NF, and stoppage time: ST) during semifinal and final matches (three 1.5-minute rounds, with 1-minute rest in between) of the 2010 Italian Taekwondo Cadet (age 13-14 years) Championship (adolescent boys, n = 40; adolescent girls, n = 28) in relation to gender (adolescent boys and girls) and grouped weight division (light, middle, and heavy) of athletes. Regardless of gender, grouped weight division, round, and tournament stage, differences (p < 0.001, effect size range: 1.92-3.02) emerged for frequency of occurrence of combat phases (F: 42.4 ± 0.5%; NF: 44.5 ± 0.7%; ST: 13.1 ± 0.9%) and their mean duration (F: 2.8 ± 1.0 seconds; NF: 6.5 ± 1.8 seconds; ST: 13.7 ± 5.0 seconds). A 1:2 F to NF ratio was found, whereas a 1:3 ratio emerged when F was considered in relation to the sum of NF and ST. During F phase, 5 ± 1 tactical movements and 4 ± 1 technical exchanges were performed, lasting 0.6 ± 0.1 seconds and 0.7 ± 0.1 seconds, respectively. These findings mirrored the intermittent nature of youth combat, characterized by a high occurrence of tactical movements and technical exchanges during F phase. The lack of differences for round and tournament stages indicates a limited tactical capability of young athletes in adopting specific match strategies, independently from gender and weight divisions of the athletes. To prepare young athletes to handle the technical-tactical demands of the match, coaches could include 7-9 circuit stations of specific taekwondo sequences of attack and counter attack techniques.

Technical and tactical analysis of youth taekwondo performance.

This study aimed to analyze the technical and tactical aspects of young athletes during official taekwondo competitions. Fifty-nine youth taekwondo athletes (43 boys and 16 girls; age range: 10-12 years; weight category range: <24 to >59 kg) with at least 2 years of taekwondo training consisting of three 90-minute training sessions for 3 d·wk⁻¹ participated in this study. Thirty-seven matches (three 1-minute rounds, with 1-minute rest in between) were analyzed to verify the differences (p ≤ 0.05) in offensive and defensive actions in relation to gender (male, female), match outcome (winners, nonwinners), kicking leg (front, rear), and round (first, second, third). No difference emerged for gender and match outcome. With respect to defensive actions (8.4 ± 12.0%), youth athletes engaged more frequently (p < 0.0001) in offensive actions (91.6 ± 12.0%), which showed a significant decrease (p < 0.016) from the first round (42.3 ± 21.8%) to the second (33.1 ± 14.8%) and third (24.5 ± 16.0%) ones. Kicks performed with the rear leg (94.4 ± 7.8%) occurred more frequently (p < 0.0001) than those performed with the front leg (5.6 ± 7.8%). In considering that a high level of coordination is required to perform front-leg kicks and defensive actions necessitate a high level of tactical skills, these findings might indicate a not-yet complete attainment of fundamental coordinative capabilities in 10- to 12-year-old athletes, independently of match outcome. To enhance coordination capabilities in youth athletes, coaches are recommended to structure their training including skill-ability and sport-ability drills.

Salivary cortisol and alpha-amylase reactivity to taekwondo competition in children.

The aim of this study was to evaluate the effects of an official taekwondo competition (three 1-min rounds with a 1-min recovery in-between) on heart rate (HR), salivary alpha-amylase (sAA), and salivary-free cortisol (sC) in children. Parental consent was obtained for 12 young (10.4 ± 0.2 years) male taekwondo athletes. Saliva sample were collected 15 min before and 1 min after an official taekwondo competition, and at 30, 60, and 90 min of the recovery period. To evaluate the exercise intensity during the competition, HR was measured and expressed as a percentage of individuals HR(peak). Athletes spent 78% of the time working at HR > 90% HR(max), with significant increases from round 1 to round 2 and 3. Peak sAA observed at the end of the match (169.6 ± 47.0 U/mL) was different (P = 0.0001) from the other samplings (pre-competition 55.0 ± 14.0 U/mL, 30-min recovery 80.4 ± 17.7 U/mL, 60-min recovery 50.5 ± 7.6 U/ml; 90-min recovery 53.2 ± 9.6 U/mL). Peak sC values observed at 30-min recovery (17.9 ± 3.5 nmol/L) were different (P < 0.0001) from pre-competition (5.6 ± 0.9 nmol/L), post-competition (9.0 ± 2.0 nmol/L), 60-min recovery (10.3 ± 2.6 nmol/L) and 90-min recovery (4.2 ± 0.8 nmol/L) values. These findings confirm that taekwondo competitions pose a high stress on young athletes. The different sAA and sC reactions in response to the physical stressor mirror the faster reactivity of the sympathetic-adrenomedullary system relatively to the hypothalamic-pituitary-adrenocortical system, respectively. This experimental paradigm might represent a useful model for further research on the effects of various stressors (i.e., training and competition) in taekwondo athletes.

Effects of official Taekwondo competitions on all-out performances of elite athletes.

This study investigated physiological and performance aspects of 15 (4 women and 11 men) elite Taekwondo athletes (24.0 ± 5.7 years) during their National Championship. The load of the competition was evaluated by means of heart rate (HR) and blood lactate (La). Pre and postmatch countermovement jump (CMJ), and handgrip performances were compared (p < 0.05). The match imposed a high load (HR > 85% of individual HRmax = 92 ± 12%; La = 6.7 ± 2.5 mmol·L⁻¹) on athletes. After the match, better (p < 0.0001) CMJ (men: 43.9 ± 5.2 cm; women: 30.8 ± 2.3 cm) and worst (p = 0.006) handgrip performances (men: 459 ± 87 N; women: 337 ± 70 N) were found with respect to prematch ones (CMJ: men = 40.8 ± 4.9 cm, women = 28.2 ± 2.5 cm; handgrip: men = 486 ± 88 N, women: 337 ± 70 N). Results indicate that the intermittent activity of the Taekwondo competition elicits a high neuromuscular activation of the lower limbs. Instead, the decreases in grip strength could be because of the repeated concussions on the upper limbs used to protect from the opponent's kicks and punches directed toward the scoring area of the torso. Practically, these results urge coaches to structure training sessions that enable athletes to maintain their upper limb strength during their match.

Effectiveness of active versus passive recovery strategies after futsal games.

This study aimed to investigate the effects of immediate postgame recovery interventions (seated rest, supine electrostimulation, low-intensity land exercises, and water exercises) on anaerobic performance (countermovement jump [CMJ], bounce jumping, 10-m sprint), hormones (salivary cortisol, urinary catecholamines), and subjective ratings (rate of perceived exertion [RPE], leg muscle pain, Questionnaire of Recovery Stress for Athletes [RestQ Sport], 10-point Likert scale), and hours of sleep of futsal players. Heart rate (HR), blood lactate, and RPE were used to evaluate the intensity of 4 futsal games in 10 players using a crossover design (P < 0.05), randomly allocating athletes to 1 of the 4 recovery interventions at the end of each game. No significant difference emerged between HR, blood lactate, RPE, and level of hydration of the games. A significant difference (P < 0.001) between games emerged for total urinary catecholamines, with an increase from the first to the second game and a gradual reduction up to the fourth game. After the game, significant reductions in CMJ (P < 0.001) and 10-m sprints (P < 0.05) emerged. No significant difference was found between recovery interventions for anaerobic performances, hormones, muscle pain, and RestQ Sport. Even though a well-balanced diet, rehydration, and controlled lifestyle might represent a sufficient recovery intervention in young elite athletes, the players perceived significantly increased benefit (P < 0.01) from the electrostimulation (7.8 +/- 1.4 points) and water exercises (7.6 +/- 2.1 points) compared to dry exercises (6.6 +/- 1.8 points) and seated rest (5.2 +/- 0.8 points.), which might improve their attitude toward playing. To induce progressive hormonal adaptation to the high exercise load of multiple games, in the last 2 weeks of the preseason, coaches should organize friendly games at a level similar to that of the competitive season.

Effects of different recovery interventions on anaerobic performances following preseason soccer training.

In the preseason soccer training, morning and afternoon training sessions often are scheduled daily. The high frequency of training sessions could place heavy strain on biological systems, and it is necessary to apply proper recovery strategies for improving the players' capability to regain an adequate working state for subsequent training units. However, the effect of recovery interventions following soccer training units is debatable, due to a lack of studies performed in field situations. The aim of this study was to examine, during a 21-day preseason soccer training, the most effective recovery intervention (i.e., passive, dry-aerobic exercises, water-aerobic exercises, electrostimulation) on anaerobic performances (i.e., squat jump, countermovement jump, bounce jumping, and 10-m sprint) and subjective ratings (i.e., perceived exertion and muscle pain), with the conditions before the intervention controlled and standardized. Twelve young (age: 18.1 +/- 1.2 years) elite soccer players participated. Data were collected on 4 occasions 2 days apart and at the same time of the day. Activity and dietary intake were replicated on each occasion. After baseline measurements, participants performed a standardized training during which their heart rates and ratings of perceived exertion were recorded. This was followed by a 20-minute recovery intervention. After a 5-hour rest, athletes' ratings of muscle pain were recorded prior to a second test session. There were no significant differences in exercise intensities and baseline anaerobic performances. Significantly (p < 0.01) better performances were observed in the afternoon. Although no main effect of recovery intervention was observed on anaerobic performances, dry-aerobic exercises (0.6 +/- 0.9) and electrostimulation (0.6 +/- 1.2) were more beneficial (p < 0.01) than water-aerobic exercises (2.1 +/- 1.1) and passive rest (2.1 +/- 1.7) for reducing muscle pain, which could affect the player's working ability.