This study aimed to quantify the external match loads (EMLs) of a Portuguese u-23 soccer team, competing at the highest national level for the age group, comparing players with different starting status throughout a competitive season and specific blocks. Thirty-five outfield soccer players were split into three groups for the entire season analysis and for each 3-month block, based on the percentage of games played as a starter. The three groups consisted of “starters” (≥55% of the games as a starter), “fringe” (30–54%), and “non-starters” (<30%). EMLs were recorded using 10 Hz GPS technology throughout the whole season (26 matches). Differences (p < 0.05) were found for total distance (TD), exposure time, and the number of accelerations and decelerations between starters and non-starters throughout the season (d = 0.73 to 1.08), and within each block (d = 0.59 to 1.68). Differences were also found between starters and fringe players for the number of accelerations in Block 2 (p = 0.03; d = 0.69), and TD (p = 0.006; d = 1) and exposure time (p = 0.006; d = 0.95) in Block 3. Differences in the EML were almost always accompanied by large differences in game time. Our results highlight the differences in the EML of starters and non-starters, emphasizing the need for compensatory training, especially with players that obtain significantly less playing time, to prepare the players for match demands (e.g., high-intensity efforts such as sprinting, accelerations, and decelerations).
7 August 2023 in International Journal of Sports Medicine
This study aimed to investigate the recovery of neuromuscular performance using mechanical parameters collected during jump (vertical and horizontal) and strength-power exercises in youth soccer players after official soccer matches. Twenty-one outfield highly trained youth male soccer athletes (age: 18.23±0.73 years; weight: 72.12±6.99 kg; height: 1.78±0.08 m) from two teams competing in the 1st division of U-19 Portuguese National Championship participated in this study. Players completed a battery of physical tests at −2 h, + 30 min, +24 h, and +48 h in relation to the match. Countermovement jump height, horizontal jump distance, and bar velocity during the half squat, bench press, and hip thrust exercises, at fixed loads, were recorded. Countermovement jump was impaired until 24 h post-match (−1.7% from pre- to 24 h post-match, p=0.050; ES=−0.82). Half-squat bar velocity was reduced immediately following the match (−6.8% from pre-match, p=0.004; ES=−0.64) but recovered at +24 h (+2.9%, p=1.00; ES=0.02). Hip-thrust bar velocity was reduced for up to 48 h post-match (−7.4% from pre- to 48 h post-match, p<0.001; ES=−0.80). No impairments were found in the horizontal jump and bench press at any moment. Our findings show prolonged decrements in strength of the posterior chain following a soccer match, measured in the hip thrust exercise, while the other exercises displayed faster recovery dynamics.
Background: The Rating-of-Fatigue (ROF) scale is a validated tool to measure changes in perceived fatigue in sports and everyday contexts; thus, this study aimed to translate and validate the Portuguese version of the ROF scale. For this, the study was composed of three phases. Phase 1 involved a comprehensive translation of the ROF scale into Portuguese, followed by a back-translation and a consolidation process to obtain the final version of the ROF scale in Portuguese. In phase 2, the face validity of the scale was assessed. Seventy-three native Portuguese speakers responded to a series of Likert scale items designed to evaluate the purpose of the scale and assess whether it accurately measured the intended construct. In the final phase, the convergent and divergent validity of the scale was assessed during an incremental cycling test to exhaustion, followed by 10 min of passive recovery and a subsequent repetition of the initial 5 min of the test. The study was conducted between October 2023 and June 2024 in Portugal. Results: The results from phase 1 indicated a high level of comparability and interpretability between the original and back-translated versions, with only minor adjustments made to finalize the Portuguese version of the ROF scale. In phase 2, a high level of face validity was observed. The median score for the item “measures fatigue” was (median [IQR]) was 3.0 [3.0, 4.0] out of 4. After participants were provided with the scale instructions, the face validity score improved significantly (4.0 [3.0, 4.0]; p = 0.001). In phase 3, during the incremental test, very large correlations were observed between ROF, and key physiological and performance indicators, including rating of perceived exertion (RPE), heart rate, oxygen consumption, and power output. Discriminant validity between ROF and RPE was found during the recovery. Conclusions: The present study indicates that the Portuguese version of the ROF maintains the properties of the original version and can be used effectively in the Portuguese language.
The current study aimed to describe sleep habits and analyze the associations between sleep indices, changes in perceived fatigue (Δ Fatigue) and external training load measures in women soccer players during a 7-day training camp. Sixteen elite women soccer players (age: 25.4 ± 3.6 years; mean ± SD) from the Portuguese Women’s National Team participated in the study. Sleep indices (sleep duration and efficiency) were measured using a wrist-worn accelerometer. External training loads measures were measured using GPS devices. Players also reported perceived fatigue using a Likert scale (1 - very, very low to 7 – very, very high) before and immediately after sleep. Players’ within-subject coefficient of variation for sleep duration was 5.6%, and 4.6% for sleep efficiency. Individually, 8 players (50%) slept less than 7 h per night throughout the training camp, and the same number of athletes had a sleep efficiency lower than 85%. Similar values (p<0.05) were measured for sleep duration and efficiency between training and match days. A moderate negative within-subjects correlation was found between Δ Fatigue and sleep duration (adjusted for pre-sleep fatigue) [r = −0.32; 95% Confidence Interval (−0.51 – −0.08); p = 0.04]. These findings reinforce the importance of sleep in the recovery process of elite women soccer players, showing that more sleep may help to attenuate fatigue.