Rodolfo André Dellagrana

Background: Echo intensity (EI) derived from ultrasound imaging is widely used to assess muscle quality and has been proposed as a potential indicator of neuromuscular performance. Recently, EI band analysis has been suggested as an alternative approach to provide additional information beyond mean EI. However, evidence linking EI bands to functional outcomes remains limited. Methods: Forty-eight male soccer players (26.2 ± 3.6 years) underwent ultrasound assessment of the vastus lateralis (VL) and rectus femoris (RF) muscles. EI was analyzed as mean values and as pixel distribution across five bands (0–50, 51–100, 101–150, 151–200, and 201–255 A.U.), with correction for subcutaneous adipose thickness. Knee extensor peak concentric torque and total work were assessed using isokinetic dynamometry at 60°/s. Generalized linear regression models were used to examine associations between EI variables and mechanical outcomes. Results: No significant differences were observed between limbs for EI mean or EI band distribution in either muscle. The 0–50 A.U. band exhibited the highest pixel percentage for both VL and RF. Mean EI of the RF was negatively associated with peak torque (β = −4.10; 95% CI: −7.35 to −0.86) and total work (β = −3.89; 95% CI: −6.34 to −1.45) of the right knee extensors. No significant associations were found for EI bands or for any EI variables of the VL muscle. In male soccer players, mean EI of the rectus femoris, but not EI band distribution, is associated with knee extensor torque and work output. Conclusions: These findings suggest that mean EI remains a more informative indicator of muscle quality related to strength performance than band-based EI analysis in this athletic population.

This study analyzed somatic maturation's effect on young soccer players’ running performance during small-sided games (SSG) and physical fitness levels. The players performed four tests sessions: 1) anthropometric assessments (body mass, height and body fat percentage), determination of peak height velocity (PHV), and physical evaluations (Carminatti test and countermovement jump); 2) Wilson protocol carried out to identify soccer talents (3 × 3, 25 × 35 m); 3 and 4) SSG on natural grass (6 × 6 including goalkeepers, 25 × 49 m), in which participants played against teams composed of players with similar and different maturation levels, respectively. More and less mature players were based on below and above PHV median values, respectively. During the SSG, players were equipped with a GPS to determine the physical variables, such as maximum heart rate, total distance (TD), average speed (AS) and number of sprints. For U-13, less mature players playing against more mature ones, presented higher TD (466.7 ± 71.4 vs 548.8 ± 51.9 m) and AS (4.9 ± 0.7 vs 5.7 ± 0.5 km·h ⁻¹ ) during the second half. For U-15, less mature players showed higher HRmax than the more mature players during matches against same maturation groups (194.1 ± 4.4 vs 181.8 ± 11.5 bpm). Biological maturation had a limited impact on running and physiological performance during small-sided games. In the U-13 category, less mature players presented higher high-speed running (HSR) compared to more mature players, regardless of opponent maturation level. In the U-15 category, HRmax was higher in less mature players than the more mature players.

The study evaluated 17 men who underwent 6 sets of 5 min downhill running (-3°, 70% of maximal aerobic speed). Before, immediately after, 24 hours, 48 hours and 72 hours after the echo-intensity (EI) of the vastus lateralis (VL) and rectus femoris (RF), the muscle pain scale (DOMS), the concentric and eccentric peak torque (PT) were evaluated for subsequent calculation of the hamstring/quadriceps (H/Q) ratios. The EI of VL and RF did not change significantly (p>0.05). DOMS increased in VL and RF between 24 and 72 h (p=0.001-0.002). The PT of the extensors decreased immediately and remained lower for 24 hours (p=0.000-0.011). The conventional H/Q ratio increased at 24 hours (p=0.043), while the functional ratio decreased immediately after exercise (p=0.020), indicating transient muscle imbalance.

This systematic review aimed to synthesize the results of studies that tested the validity, reproducibility, and concordance of the standard methods of mobile applications used to estimate vertical jumps. The search was conducted in PubMed, Scopus, and Web of Science. Twenty studies were included in the systematic review, and 16 studies were included in the meta-analysis. Good to excellent intraclass and interrater reliabilities (84–1.00) were observed for all jumps. The meta-analysis identified a moderating effect on the Bland-Altman bias ( p ≤ 0.05), and no moderator effect for jump type ( p ≤ 0.51) and reference method ( p ≤ 0.90). The Jumpo app overestimated jump height by 1.42 (0.06–2.78) cm, and the MyJump app presented values similar to those of the reference methods (0.0 [−0.23 to 0.22] cm). The data suggest that the vertical jump height estimated using smartphone apps is highly reliable within and across different assessors, irrespective of jump type and app. In addition, the jump height estimated with the MyJump app closely agrees with other standard methods that use flight-time equations. However, we recommend considering the overestimation of jump height when using the Jumpo app compared with the MyJump app.

Background/Objectives: Internal training load has been widely used to monitor training intensity and to prevent injuries in different sports. This study aimed to analyze the association between internal training parameters and sports injury incidence in gymnasts based on different training week exposure levels during a sequential sports season. Methods: The participants consisted of 27 gymnasts, aged 8 to 17 years old, recruited into two gymnastics training centers. The subjects were allocated into two groups: medium exposure (ME) and low exposure (LE) athletes. The monitoring period totaled 28 weeks. A survey was conducted to monitor sports injury incidence. The Perceived Effort Scale and the Total Quality of Recovery were applied to monitor training load and recovery, respectively. Results: A total of 28 injury cases were reported, with a higher incidence (24) in the ME group than in the LE group. Furthermore, the ME group demonstrated a significant increase in the average weekly load, as well as higher values of monotony and strain compared to the LE group (p < 0.001). The acute: chronic workload ratio (ACWR) was lower in the ME than in the LE group in all training periods. The total quality recovery (TQR) exhibited a peak during the competitive training period in the ME group, whereas strain showed a direct effect on this result. Conclusions: Increased training load values were linked to the incidence of musculoskeletal injuries in gymnasts submitted to different training week exposure levels. Likewise, the high values of internal training load were shown to be related to impaired recovery during a competitive period within a 28-week follow-up.

The 2022 Qatar World Cup was conducted under unique circumstances, setting it apart from previous editions due to schedule and rule modifications. This study aimed to evaluate the physical demand of teams in terms of running disparities between the 2018 and 2022 World Cups. Match performance data were obtained from the official websites of the 2018 Russia World Cup (n = 988 observations) and the 2022 Qatar World Cup (n = 826 observations). Match outcomes included losses (n = 729 player observations), draws (n = 339 player observations), or wins (n = 746 player observations). Players in all positions covered a greater distance during the 2022 World Cup compared to the 2018 edition. When examining the interaction between Cup and Outcome, only total distance covered (F = 5.831, p = 0.003) and distance covered walking (F = 15.488, p < 0.001) showed statistical differences. These findings elucidate that more total distance was covered during draws, with higher values observed in the 2022 World Cup. Thus, the study concludes that the 2022 Qatar FIFA World Cup presented a higher physical match demand compared to the 2018 Russia FIFA World Cup.

The aim of this systematic review was to identify and synthesize the available information in studies that compare the physical responses of young football players subjected to games in two distinct competition models: the bio-banded model, which considers the stage of biological maturation, and the chronological model, based solely on the age of the players. The conduction of this review followed the guidelines of the Preferred Reporting Items for Systematic and Meta-Analyses (PRISMA). Bibliographic searches were performed in three databases: PubMed, Web of Science, and SCOPUS, using the following descriptors: "soccer game", "physical performance", "biological maturation", and "bio-banding". The inclusion criteria were articles with experimental studies conducted in a game context, which compared the physical responses of players during bio-banded and chronological competitions, with the aim of investigating the influence of biological maturation on these responses. The initial search resulted in 336 records, of which 4 articles comprised the final sample. The methodological quality of the included studies was assessed as medium to high. The findings suggest that biological maturation has an influence on the physical responses of young football players, and that both late-maturing and early-maturing players can benefit from games organized by biological maturation status.

Transgender people may opt for the use of sex steroids and, in some cases, hormone blockers, which can lead to changes in body fat distribution. The aim of this study was to verify the accuracy of anthropometric equations to estimate the body density (BD) of transgender men who are undergoing Gender-Affirming Hormone Therapy (GAHT). Four transgender men (25-32 years old), who had performed GAHT for at least six months and used the hormone testosterone cypionate participated in the study. The reference criteria for BD was air displacement plethysmography (ADP). In addition, BD was estimated using anthropometric equations for both male and female sexes (Durnin & Womersley, 1974; Jackson & Pollock 1980; Lohman, 1981). The body fat percentage (%BF) was estimated by the Siri equation. For two participants (Cases 1 and 3), the equations for males underestimated the %BF, while only for Case 3 the equation for both sexes underestimated the %BF. For the other two participants (Cases 2 and 4), all equations overestimated the %BF. Of note, one participant undergoing GAHT for six months showed a %BF assessed by ADP like values obtained using equations for cisgender women, while those with longer time on GAHT presented similar %BF obtained by ADP to obtained by equations developed for cisgender men. In conclusion, the results of this study indicate the need to develop specific anthropometric equations for the transgender population. In addition, the time on GAHT of the transgender person seems to be a critical factor.

The aim of this study was to verify post-activation performance enhancement (PAPE) in jumping and sprinting after two endurance volume-equated running protocols with different intensities, in runners vs. active individuals. Nine recreational runners (age: 34.5 ± 9.3 years, body mass: 73.1 ± 11.9 kg, body height: 1.76 ± 0.06 m, 17.4 ± 4.4 %body fat; maximum aerobic speed [MAS]: 16.4 ± 1.0 km·h−1), and 9 active individuals (age: 34.1 ± 9.4 years; body mass: 83.2 ± 7.7 kg; body height: 1.79 ± 0.06 m; 25.6 ± 5.4 %body fat; MAS: 13.3 ± 1.2 km·h−1) volunteered for participation. The evaluations were performed over three days as follows: 1) anthropometric measures, physical fitness tests, and the University of Montreal Track Test (UMTT) to determine MAS and the distance to be covered in the running protocols; 2 and 3) the countermovement jump (CMJ) and the flying 20-m sprint (SPRINT) were assessed pre- and post-running at 70% of MAS or a time trial race (TTR), equated by volume and completed in random order. A three-way ANOVA (time*group*running) was performed to analyze the PAPE effects. The results showed a time effect (F = 10 .716; p < 0.01) and a group*running interaction (F = 12.094; p < 0.01) for the CMJ, indicating that active individuals demonstrated PAPE after running at 70% of MAS, while for runners both running interventions (70% of MAS and TTR) induced PAPE in CMJ performances. For the SPRINT, a time*group interaction (F = 4.790; p = 0.044) and a group effect were observed, with runners showing greater SPRINT performances than active individuals. From the current results, it can be suggested that training background and intensity can modulate PAPE responses in jumping and sprinting after volume-equated running protocols at different intensities.