Biology of Sport最新文献

The study aimed to provide reference values of cardiorespiratory parameters and maximal exercise velocity (MEV) of first-division soccer players measured during a ramp exercise running test. A large (N = 741) database of cardiopulmonary exercise tests collected over a decade on Serie A teams in Italy was scrutinized. The reference values were stratified for age, playing position, and season phase. We found an average $\dot{\text{V}}{\text{O}}_2$ peak of 4.78 ± 0.56 l/min, a relative $\dot{\text{V}}{\text{O}}_2$ peak of 61.5 ± 5.96 ml/kg/min and an MEV of 19.0 ± 1.3 km/h. Relative $\dot{\text{V}}{\text{O}}_2$ peak was constant from 18 to 30 years of age and then decreased, while MEV decreased constantly with increasing age. While the absolute $\dot{\text{V}}{\text{O}}_2$ peak was similar for all playing roles (P = 0.782), the midfielders were the players with the highest relative $\dot{\text{V}}{\text{O}}_2$ peak (P = 0.020) and they had lower body mass than the others (P < 0.001). This study presents estimates of the influence of age, player position, and season phase on $\dot{\text{V}}{\text{O}}_2$ peak in men's elite soccer. $\dot{\text{V}}{\text{O}}_2$ peak values ~62 ml/kg/min fulfil the demands for $\dot{\text{V}}{\text{O}}_2$ peak in men's professional soccer. Midfielders showed larger relative, but not absolute, $\dot{\text{V}}{\text{O}}_2$ peak.

This study aimed to compare microcycle loading and sleep patterns concerning successive match days (MD) using objective measurements of sleep and external training load (eTL). Twenty professional female soccer players (mean age: 23.3 ± 3.5 years) were monitored using a multi-sensor sleep-tracker for sleep patterns and global positioning system devices for eTL. Sleep variables included total sleep time (TOTAL), awake time (AWAKE), REM sleep, deep sleep time (DEEP), light sleep time (LIGHT), percentage of sleep time spent moving (REST), and sleep onset latency (ONSET). eTL variables included total distance covered (TD), distance at various speed thresholds, accelerations (ACC3), and decelerations (DEC3). 1) eTL influenced sleep; 2) TOTAL and REM were reduced after high eTL sessions (MD-3); 3) MD-2 facilitated recovery and improved post-session sleep compared to MD-4 and MD-3; 4) post-session TOTAL and DEEP sleep times on MD-1 were shorter compared to pre-session times, but there was no difference in REM sleep. Additionally, DEEP had a negative correlation with eTL variables, while REST had a positive correlation with certain eTL variables. REM sleep was affected after high eTL sessions, indicating that fatigue negatively impacted sleep. However, sleep increased after lower eTL sessions. Players slept less with less DEEP sleep the day before a competition (MD-1 post-session sleep). Monitoring sleep during microcycle acquisition and loading phases could assess sleep changes. Strategies should be implemented to improve sleep during loading phases and the night before matches.

This study investigated the kinetics of skin temperature (Tsk) in the lower limbs of elite soccer players following official matches, with measurements taken at three time points: pre-game (M1), 24 hours after a match (M2), and 48 hours after a match (M3). Additionally, we explored the correlation between Tsk and individualized creatine kinase (CK) levels. Thirty male athletes from a top-tier professional soccer club were assessed during the Brazilian Serie A Championship. CK levels and Tsk in the lower limbs were recorded at M1, M2, and M3. Tsk was significantly elevated at M2 compared to M1 (P < 0.001) and decreased at M3, although it did not return to baseline levels (P < 0.001). A significant positive correlation was found between Tsk in all regions of interest (ROIs) and the percentage of CK, with the lowest correlation observed at r = 0.52 (P < 0.001). Tsk in the lower limbs showed a pattern similar to CK, being elevated at 24 h after the match and decreasing by 48 h but not fully returning to pre-game levels. These findings suggest that Tsk can complement CK measurements and be useful in training control and recovery strategies for elite soccer athletes.

This study aimed to analyze the effects of microcycle length on external and internal load during training sessions and official matches in a professional female soccer team. A total of 32 microcycles were monitored for 20 outfield players using a portable 10 Hz GPS device. Microcycles were categorized by length as short (5-6 days), regular (7 days), or long (8-9 days). Training load during the microcycles was analyzed relative to the days before or after the match day (MD), considering the following sessions: MD+1, MD-4, MD-3, MD-2, and MD-1. The external load was assessed according to total distance (TD), high-intensity running distance (HIR), sprint distance (SPD), and number of high-intensity accelerations (ACC) and decelerations (DEC). Internal load was measured using the rating of perceived exertion (RPE) and session RPE (s-RPE). The results of linear mixed model analyses showed that TD (d = 1.24-1.35), ACC (d = 0.64-0.66), and DEC (d = 0.90-1.04) were significantly higher on MD+1 in short microcycles compared to regular and long microcycles. On MD-4, large differences were observed between long and short microcycles for TD (d = 1.60), ACC (d = 1.28), DEC (d = 1.28), RPE (d = 1.25), and s-RPE (d = 1.61). Similarly, MD-3 of long microcycles showed significantly higher TD (d = 1.25-1.32), HIR (d = 1.18-1.32), and SPD (d = 0.84-1.68) compared to regular and short microcycles. On MD-2, the highest workload was observed in short microcycles, especially for SPD (d = 1.15-1.34). Overall, this study demonstrated that the external and internal load of training sessions vary depending on the length of the microcycles in professional female soccer.

To identify a relationship between the 1200 m shuttle test and 40 m sprint test performance with distances covered at varying intensities in English Premier League (EPL) matches. A squad (n = 21) of full-time professional 1^st team male football players (age 29.8 ± 3.4 years; height 183.7 ± 5.2 cm; weight 83.7 ± 6.9 kg) participated in this study. League match data from the 2019-20 and 2020-21 seasons were recorded and analysed via an Optical Tracking System (OTS) (Second Spectrum^®, Los Angeles, USA) to report physical match performance data. Average velocity during the 1200 m shuttle test (V1.2ST) was calculated, while Peak sprinting speed (PSS) was estimated using a 40 m maximal sprint. ASR1.2ST was established by subtracting V1.2ST from PSS. The relationship between V1.2ST, 30%ASR1.2ST and distances covered at varying intensities in EPL matches was assessed by a series of independent Linear Mixed Effects (LME) models. Although not statistically significant, for every unit increase in V1.2ST, there was an increase of 1032 m in distance covered, (p = 0.07). A single unit increase in 30%ASR1.2ST is associated with a significant increase of 495 m in high-speed running distance (> 5.5 m · s^-1) (p = 0.02). While for each unit increase in 30%ASR1.2ST, sprint distance (> 7 m · s^-1) covered significantly increased by 209 m (p = 0.02). In conclusion, high levels of physical fitness such as V1.2ST and 30%ASR1.2ST derived from the 1200 m shuttle and 40 m sprint tests can improve match running performance in elite soccer. Knowledge of this information allows practitioners to tailor training load based on each players individual characteristics, potentially increasing performance.

Priming activities have been widely used by coaches as a strategy to enhance physical performance within short periods (6-24 hours) before sport-specific training sessions and competitions. In this crossover study, we examined and compared the effects of two different priming schemes on the speed-power performance of female rugby sevens players. One hour after completing a standardized warm-up and a series of measurements including loaded and unloaded jumps and speed-related tests, twenty Olympic female rugby sevens players performed, one week apart, 6 sets of 6 reps of jump-squats (JS) at either 40% (light-load; LL) or 80% 1RM (heavy-load; HL). Countermovement jump height increased significantly 6-h after both loading conditions (ES=0.50 and 0.34, for LL and HL, respectively; P < .001), with no changes observed at the 24-h time-point. JS peak velocity improved significantly after 24-h compared to the pre-testing, but solely for the lighter loading intensity (i.e., JS at 40%1RM; ES=0.63; P=0.006). 40-m sprinting speed increased significantly at the 6-h timepoint for both LL (ES=0.20; P=0.001) and HL (ES=0.18; P=0.004), without showing significant changes in the following 24-h. COD speed improved significantly after both priming schemes at the 6- and 24-h time points, regardless of the loading condition (P ≤ 0.027 for the main effect of time). No time × loading condition interaction was detected for any variable assessed, with P-values ranging from 0.111 to 0.953. Importantly, the rate of perceived exertion was significantly higher after the priming protocol at the HL condition (P=0.02), which may lead to increased levels of fatigue and decreased performance in subsequent activities. Elite coaches from rugby sevens (and other team sports) should strongly consider these findings when programming priming training sessions in the periods preceding more intensive training sessions and official matches due to the potential disadvantages associated with the use of heavier loads (i.e., ≥ 80% 1RM).

The aims of the present study were to: (1) analyse the upper and lower match physical performance benchmarks and variability of teams at the FIFA Women's World Cup Australia and New Zealand 2023, (2) examine the evolving team sprint ranking across three Women's World Cups and (3) investigate noteworthy relationships between collective physical and tactical metrics. With FIFA's official approval, all sixty-four games at the tournament were analysed using an optical tracking system alongside FIFA's Enhanced Football Intelligence metrics. On average, teams at the FIFA Women's World Cup 2023 covered 103.3 ± 4.4 km in total, with 6.7 ± 0.6 km and 1.9 ± 0.3 km covered at the higher intensities (≥19.0 & ≥23.0 km · h^-1), respectively. The top five ranked teams from a high-intensity running perspective (Zambia, Spain, Brazil, Canada, Denmark) covered 24-44% more distance than the bottom five ranked teams (Jamaica, Columbia, Costa Rica, Switzerland, Vietnam) at the tournament (P < 0.01; Effect Size [ES]: 2.3-2.5). Match-to-match variation of teams revealed Italy and Panama were particularly consistent for the distances covered at higher intensities (Coefficient of Variation [CV]: 0.3-4.5%), while Costa Rica demonstrated considerable variation (CV: 23.4-40.7%). Teams generally covered more total distance on a per-minute basis in the first versus the second half (P < 0.01; ES: 1.1), but no differences existed at higher intensities (P > 0.05; ES: 0.1-0.2). Correlations were found between the number of high-intensity runs and various phase of play events for defensive transitions and recoveries, in addition to progressions up the pitch and into the final third (r = 0.48-0.88; P < 0.01). A basic comparative analysis revealed Spain demonstrated the most pronounced increase (2015 = 9^th, 2019 = 35^th, 2023 = 90^th percentile; CV: 92.6%) and China PR the most marked decrease (2015 = 22^nd, 2019 = 30^th, 2023 = 0 percentile; CV: 89.6%) in their sprinting percentile rank across the last three FIFA Women's World Cups. The present findings provide a depiction of the current collective demands of international women's football. This information could be useful for practitioners to benchmark team performances and to potentially understand the myriad of contextual factors impacting physical performances.

This study investigated the extent to which biological maturity and relative age biases existed and varied with chronological age in female international youth soccer players relative to the general population. A total of 113 players (52 under-15 (U15), 32 under-16 (U16) and 29 under-17 (U17)) selected by the Football Association of Ireland participated in this study. All players were assessed for height, body weight and relative age. Biological maturity status and timing were assessed in U15 and U16 players only. Relative to population norms, the results showed a significant but small bias in favour of more biologically mature players (P < 0.001, d = 0.39) that increased with age from U15 (P = 0.007, d = 0.36) to U16 (P = 0.009, d = 0.44). U16 players had achieved a significantly higher percentage of their predicted adult height than U15 players (T = 7.4, P < 0.001). However, there were no relative age biases at any age group nor across the total sample (P > 0.05). There was no significant difference in height, weight or relative age of the players between the three age groups and no significant difference between the U15 and U16 age groups in terms of predicted adult height or biological to chronological age offset. This study demonstrates that biological maturity but not relative age biases exist in female international youth football relative to the general population, with notable differences in pattern and magnitude compared to those previously observed in male international youth football.

The objectives of this study were to compare the external load of position games and matches in soccer players and to assess the effect of different pitch sizes on position games in relation to competition. Twenty-five players (age: 21.9 ± 1.9 years; height: 177.9 ± 5.2 cm; weight: 75.5 ± 4.8 kg) were evaluated during 37 official matches and 18 position games classified according to their pitch sizes: Small, Medium and Large (50.8 ± 6.6 m², 80.5 ± 4.6 m² and 115.9 ± 25.2 m² relative area per player, respectively). Using a GPS system, total distance (DC), DC > 21 km · h^-1, peak speed, and maximal accelerations and decelerations lower and higher than 3 m · s^-2 (Acc_<3; Acc_>3; Dec_<3 and Dec_>3, respectively) were recorded. Mixed model analyses were used to compare the effects of the game condition and of space dimensions on the dependent parameters. During the position games, lower values of DC, DC > 21 km · h^-1, peak speed, Acc_<3, Dec_<3, maximal accelerations and maximal decelerations were reported than in matches. Position games showed higher values than matches for the Acc_>3 and Dec_>3. All analysed variables reached statistical significance (all p < 0.001). Small, Medium and Large position games significantly achieved lower DC > 21 km · h^-1, peak speed, Acc_<3, Dec_<3, maximal accelerations and maximal decelerations, but significantly higher Acc_>3 and Dec_>3 (all p < 0.05) than matches. The data showed that position games of 9 vs. 9 + 2 with a relative area per player ≤ 115.9 m² present a different external load than matches.

Aerobic physical exercise has significant benefits for cardiovascular health; however, some individuals experience no benefit or even adverse effects. One reason for poor tolerance to aerobic exercise may be a low percentage of slow-twitch (oxidative) muscle fibers. This study aims to identify the metabolic signatures associated with low and high response to exercise by comparing the metabolic profiles of participants categorized according to their improvement of the 6-minute walking distance. In this study, pre- and postexercise intervention measurements of the 6-minute walking distance were conducted in forty-three lean and overweight young women, followed by non-targeted metabolomics analysis of 1039 known metabolites. An independent validation cohort comprising 791 individuals from the GTEx project was used to assess the gene expression of selected targets. The results indicated that a low improvement in the 6-minute walking distance (Δ 6-MWD = 27 meters) was associated with higher serum levels of N-lactoyl amino acid metabolites, particularly the exercise-inducible metabolite N-lactoyl phenylalanine (Lac-Phe) (FDR = 0.016), compared to high responders. Our results were corroborated in an independent validation cohort, which showed that the gene expression of cytosolic nonspecific dipeptidase (CNDP2), the enzyme responsible for Lac-Phe synthesis, is negatively associated with the percentage of slow-twitch muscle fibers (p < 0.0001). N-lactoyl amino acids may serve as biomarkers for rapid muscle fatigue and low response to exercise, and could be used as metabolic indicators to differentiate exercise response efficacy.