Energetics of sinusoidal exercise below and across critical power and the effects of fatigue.

PURPOSE: Previous studies investigating sinusoidal exercise were not devoted to an analysis of its energetics and of the effects of fatigue. We aimed to determine the contribution of aerobic and anaerobic lactic metabolism to the energy balance and investigate the fatigue effects on the cardiorespiratory and metabolic responses to sinusoidal protocols, across and below critical power (CP). METHODS: Eight males (26.6 ± 6.2 years; 75.6 ± 8.7 kg; maximum oxygen uptake 52.8 ± 7.9 ml·min-1·kg-1; CP 218 ± 13 W) underwent exhausting sinusoidal cycloergometric exercises, with sinusoid midpoint (MP) at CP (CPex) and 50 W below CP (CP-50ex). Sinusoid amplitude (AMP) and period were 50 W and 4 min, respectively. MP, AMP, and time-delay (tD) between mechanical and metabolic signals of expiratory ventilation ( V ˙ E ), oxygen uptake ( V ˙ O 2 ), and heart rate ( f H ) were assessed sinusoid-by-sinusoid. Blood lactate ([La-]) and rate of perceived exertion (RPE) were determined at each sinusoid. RESULTS: V ˙ O 2 AMP was 304 ± 11 and 488 ± 36 ml·min-1 in CPex and CP-50ex, respectively. Asymmetries between rising and declining sinusoid phases occurred in CPex (36.1 ± 7.7 vs. 41.4 ± 9.7 s for V ˙ O 2 tD up and tD down, respectively; P < 0.01), with unchanged tDs. V ˙ O 2 MP and RPE increased progressively during CPex. [La-] increased by 2.1 mM in CPex but remained stable during CP-50ex. Anaerobic contribution was larger in CPex than CP-50ex. CONCLUSION: The lower aerobic component during CPex than CP-50ex associated with lactate accumulation explained lower V ˙ O 2 AMP in CPex. The asymmetries in CPex suggest progressive decline of muscle phosphocreatine concentration, leading to fatigue, as witnessed by RPE.

A comparative video analysis of hamstring injuries mechanism and situational pattern in men's and women's football (soccer).

PURPOSE: To describe the injury mechanism and situational patterns of severe (absence >28 days) hamstring muscle injuries in professional male and female football (soccer) players. METHODS: The data for males were sourced from Serie A clubs participating in both national and international competitions from 2018 to 2021. For the female cohort, hamstring injuries were identified during matches of the top national/international competitions from 2017 to 2023. Video footage was obtained, and three raters categorised injury mechanisms and situational patterns. Injuries were also examined according to the month, minute and location. RESULTS: A total of 129 severe hamstring injuries were identified, with 64 occurring in females and 65 in males. Video analysis was possible for 29 (45%) female cases and 61 (94%) male cases. Female injuries had longer lay-off times (97.8 ± 77.1 days) than males (39.6 ± 20.9 days). Females had a higher proportion of indirect contact injuries (34%) than males (13%) and a lower proportion of non-contact injuries (66% vs. 87%). Four situational patterns were identified: running was the most common for both sexes, representing 59% of female injuries and 41% of male injuries. Over-stretching injuries were split across open and CKC scenarios but collectively explained nearly half (48%) of male injuries but only one in five (21%) female injuries. Kicking injuries had a higher proportion in females (17%) than males (10%). Injuries were more common in the second half for females and the first half for males. CONCLUSION: Females had a higher proportion of indirect contact, running and kicking injuries and a lower proportion of non-contact and stretch-type injuries than males. Understanding injury patterns can inform tailored prevention programs, considering sex-specific differences. LEVEL OF EVIDENCE: Level IV.

Validation of Step Detection and Distance Calculation Algorithms for Soccer Performance Monitoring.

This study focused on developing and evaluating a gyroscope-based step counter algorithm using inertial measurement unit (IMU) readings for precise athletic performance monitoring in soccer. The research aimed to provide reliable step detection and distance estimation tailored to soccer-specific movements, including various running speeds and directional changes. Real-time algorithms utilizing shank angular data from gyroscopes were created. Experiments were conducted on a specially designed soccer-specific testing circuit performed by 15 athletes, simulating a range of locomotion activities such as walking, jogging, and high-intensity actions. The algorithm outcome was compared with manually tagged data from a high-quality video camera-based system for validation, by assessing the agreement between the paired values using limits of agreement, concordance correlation coefficient, and further metrics. Results returned a step detection accuracy of 95.8% and a distance estimation Root Mean Square Error (RMSE) of 17.6 m over about 202 m of track. A sub-sample (N = 6) also wore two pairs of devices concurrently to evaluate inter-unit reliability. The performance analysis suggested that the algorithm was effective and reliable in tracking diverse soccer-specific movements. The proposed algorithm offered a robust and efficient solution for tracking step count and distance covered in soccer, particularly beneficial in indoor environments where global navigation satellite systems are not feasible. This advancement in sports technology widens the spectrum of tools for coaches and athletes in monitoring soccer performance.

En Bloc enucleation with early apical release technique using MOSES (En Bloc MoLEP) vs. classic En Bloc HoLEP: a single arm study comparing intra- and postoperative outcomes.

BACKGROUND AND PURPOSE: We aimed to describe the technique and outcomes of En-Bloc MOSES laser enucleation of the prostate (En-Bloc MoLEP) with early apical release comparing it to En-Bloc HoLEP (non-MOSES). PATIENTS AND METHODS: This is a single-arm prospective study, using a historical control. n = 80 patients were enrolled to the En Bloc MoLEP group and compared to a retrospective group of n = 137 patients treated by En Bloc HoLEP (non-MOSES), in total n = 217 patients. RESULTS: En-Bloc MoLEP, showed to significantly improve the surgical time by 32% compared to non-MOSES HoLEP (32.16 ± 14.46 min, 47.58 ± 21.32, respectively; P = 0.003). Enucleation time, ablation rate and hemostasis time were also significantly improved (P < 0.001, for all three parameters). Enucleation time was 22.10 ± 9.27 min and 31.46 ± 14.85 min (P < 0.001), ablation rate 4.11 ± 2.41 and 2.54 ± 1.31 gr/min (P < 0.001), Hemostasis time 3.01 ± 2.50 and 8.35 ± 5.38 min (P < 0.001), for En Bloc MoLEP and En Bloc HoLEP, respectively. Q-max, PVR, PSA and IPSS showed significant improvement, however, at 12 months no significant differences were observed comparing both groups. CONCLUSIONS: En-Bloc MoLEP was significantly better than En-Bloc HoLEP in terms of surgical time, enucleation time, ablation rate and hemostasis time. However, large comparative RCT with long-term follow-up are needed.

α-Glucosidase inhibition by green, white and oolong teas: in vitro activity and computational studies.

Natural α-glucosidase inhibitors from plant-based foods such as catechins offer an attractive strategy for their potential anti-diabetic effects. In this study, infusions of three different tea types (green, white, and oolong) were investigated for their total phenolic (TPC) and catechins (EGCG, ECG, EGC, and EC) content, and for their α-glucosidase inhibitory activities. We observed that the level of TPC in white tea was significantly higher compared to oolong and green tea, which suggests higher content of EGCG and ECG catechins in fresh young leaves. Our findings showed that the higher content of such catechins in the infusion of white tea well correlated with a strong inhibition of α-glucosidase, and such inhibition was demonstrated to be more effective than the FDA-approved drug acarbose. Then, we computationally explored the molecular requirements for enzyme inhibition, especially for the most active catechins EGCG and ECG, as well as their disposition/stability within the active site.

Small-Sided Games in Elite Football: Practical Solutions to Replicate the 4-min Match-Derived Maximal Intensities.

ABSTRACT: Riboli, A, Esposito, F, and Coratella, G. Small-sided games in elite football: practical solutions to replicate the 4-min match-derived maximal intensities. J Strength Cond Res 37(2): 366-374, 2023-The purpose of the study was to determine the area per player (ApP, m 2 ·player -1 ) to replicate the maximal 4-min match-play period (4-min Peak ) using small-sided or large-sided games (SSGs) lasting the same duration in elite football players. Twenty players (age: 26 ± 5 years) competing in European championship and international UEFA competitions were monitored during SSGs with (SSG with ) or without (SSG without ) goalkeepers, both lasting 4-min. A total of 1,724 and 561 individual observations for SSG with and SSG without across 99 and 34 different SSGs formats were undertaken. Whole (90-min avg ) and 4-min Peak match demands were calculated. Relative (m·min -1 ) total, high-speed (HSRD), very high-speed (VHSRD), sprint, and acceleration/deceleration distance were collected. For both SSG with and SSG without , ApP was small -to- very-largely correlated with TD, HSRD, VHSRD, and sprint, whereas an inverse trivial -to- small correlation with acceleration/deceleration was found. In SSG with , the ApP to replicate 4-min Peak was larger ( p < 0.001, effect size [ES]: 0.33-5.80) than that to mimic 90-min avg for total distance, HSRD, VHSRD, and sprint, whereas for acceleration/deceleration the ApP was lower ( p < 0.001, ES: -3.13 to 0.48) for 4-min Peak . In SSG without , the ApP to replicate 4-min Peak was larger ( p < 0.001, ES: 0.04-3.72) than that to mimic 90-min avg for HSRD, VHSRD, and sprint. Some positional differences ( p < 0.05, ES: 0.22-1.10) in ApP were found. The ApP to replicate 4-min Peak was higher for SSG with than SSG without ( p < 0.001, ES: 0.67-3.58). These findings may help practitioners to recreate the 4-min Peak to manage ApP during SSGs in elite football.

Technical and locomotor demands in elite soccer: manipulating area per player during small-sided games to replicate official match demands.

The present study aimed to investigate the area per player (ApP) to replicate the technical and locomotor match demands using small-sided games (SSGs) in male soccer players (n = 20) competing in major European and UEFA competitions. The relative number of each individual technical activity per minute (number · min-1; technical demands) was counted and the relative (m · min-1) total (TD), high-speed running (HSRD), very high-speed running (VHSRD), sprint and acceleration+deceleration (Acc+Dec) distances were collected during different SSG formats (n = 24; 4 vs 4 to 10 vs 10 with an ApP from 60 to 341 m2 · player-1) and official matches (n = 28). Data were collected during two full seasons. A linear mixed model analysis was used to calculate the individual relationship between technical/locomotor demands and the ApP during SSGs; the correlation coefficient was also calculated. With the exception of an inverse moderate (r = -0.457) correlation for Acc+Dec, each locomotor metric (TD, HSRD, VHSRD and sprint) showed a positive large to very large (r = 0.560 to 0.710) correlation with ApP (P < 0.001). The technical demands showed an inverse moderate correlation (r = -0.529) with ApP. Additionally, inverse moderate to large correlations (r = -0.397 to -0.600; P < 0.05) between the technical demands and the locomotor demands (TD, HSR, VHSR and sprint) were found. Lastly, an ApP of ~243 m2 · player was found to replicate the official match technical demand and it was quite similar to the ApP required to replicate HSRD, VHSRD and sprint. These findings may help practitioners to replicate, overload and underload both technical and locomotor demands using a specific ApP during SSGs in elite soccer.

Marathon shoes vs. track spikes: a crossover pilot study on metabolic demand at different speeds in experienced runners.

The aim of this study was to assess the metabolic cost (Cr) with marathon shoes (Adidas Adizero 3 [AA]) vs. track spikes (Nike Zoom Matumbo 3 [NZM]) on track. For this, five experienced runners were randomly assessed (NZM/AA) on a running track at 73% and 85% of best performance speed on 1500-m race. At first, speed (4.39 ± 0.53 m·s-1), Crs with AA and NZM resulted 3.63 ± 0.29 and 3.64 ± 0.43 J·kg-1·m-1 (+0.3% with NZM, effect size [ES] small and p = 0.951), respectively. Besides, at second speed (5.20 ± 0.18 m·s-1), Crs were 4.09 ± 0.28 and 4.07 ± 0.22 J·kg-1·m-1 (-0.5% with NZM, ES small and p = 0.919) with AA and NZM, respectively. It resulted in an increased Cr (+12.2%) between s1 and s2 with both shoe conditions (ES large and p = 0.009 and 0.011 with AA and NZM, respectively). There is a pattern yet to be confirmed for track spikes to become more beneficial at higher speeds (when duty factor becomes lower and therefore grip on track is crucial).

Determining voluntary activation in synergistic muscles: a novel mechanomyographic approach.

PURPOSE: Drawing on correlations between the mechanomyographic (MMG) and the force signal, we devised a novel approach based on MMG signal analysis to detect voluntary activation (VA) of the synergistic superficial heads of the quadriceps muscle. We hypothesized that, after a fatiguing exercise, the changes in the evoked MMG signal of each quadriceps head would correlate with the changes in the level of VA in the whole quadriceps. METHODS: Twenty-five men underwent a unilateral single-leg quadriceps exercise to failure. Before and after exercise, VA was assessed by interpolated-twitch-technique via nerve stimulation during and after maximum voluntary contraction (MVC). The force and MMG signal were recorded from vastus lateralis, vastus medialis, and rectus femoris. The MMG peak-to-peak was calculated and the voluntary activation index (VAMMG), defined as the superimposed/potentiated MMG peak-to-peak ratio, was determined from the MMG signal for each head. RESULTS: VAMMG presented a very high intraclass correlation coefficient (0.981-0.998) and sensitivity (MDC95%: 0.42-6.97%). MVC and VA were decreased after exercise in both the exercising [MVC:-17(5)%, ES -0.92; VA: -7(3)%, ES -1.90] and the contralateral limb [MVC: -9(4)%, ES -0.48; VA: -4(1)%, ES -1.51]. VAMMG was decreased in both the exercising [~ -9(6)%, ES -1.77] and contralateral limb [~ -3(2)%, ES -0.57], with a greater decrease in VAMMG noted only in the vastus medialis of the exercising limb. Moderate-to-very high correlations were found between VAMMG and VA (R-range: 0.503-0.886) before and after exercise. CONCLUSION: VAMMG may be implemented to assess VA and provide further information when multiple synergistic muscle heads are involved in fatiguing exercises.

Injury Burden in Professional European Football (Soccer): Systematic Review, Meta-Analysis, and Economic Considerations.

OBJECTIVE: We performed a systematic review and meta-analysis to evaluate the injury burden and the related economic cost in European professional male football players. DATA SOURCES: Multiple database research was performed up to August 5, 2022 (PubMed, EMbase, Scopus, Cochrane Library), including only studies that reported severity in the number of days of absence for each injury, incidence reported in the number of injuries/1000 hours, or reported number of injuries and exposure time and adult male football players, professionals from European clubs. Two reviewers extracted data and assessed paper quality with the Strengthening the Reporting of Observational Studies in Epidemiology statement and the Newcastle-Ottawa Scale. MAIN RESULTS: Twenty-two studies have reported incidence, severity, and burden of injuries in professional football. The highest injury burden was found for ligament-joint injuries (37.9 days/1000 hours; 222 397 €/1000 hours) and for muscle injuries (34.7 days/1000 hours; 203 620 €/1000 hours). Injury locations with high burden were knee injuries (34.8 days/1000 hours; 20 4206 €/1000 hours)-mainly anterior cruciate ligament injuries (14.4 days/1000 hours; 84 499 €/1000 h)-followed by thigh injuries (25.0 days/1000 hours; 146 700 €/1000 hours), hamstrings injuries (15.4 days/1000 hours; 90 367 €/1000 hours), hip-and-groin injuries (16.1 days/1000 hours; 94 475 €/1000 hours), primarily adductor muscles injuries (9.4 days/1000 hours; 55 159€/1000 hours), and ankle injuries (13.1 days/1000 h; 76 871 €/1000 hours) with ankle sprains (7.4 days/1000 hours; 43 423 €/1000 hours). CONCLUSIONS: Being exposed to injury risk has serious consequences for individual and club performance and economy. This review identified the most relevant targets in injury management, compared their injury data with reference values, and provided economic evidence when trying to gain buy-in from the key decision makers.

The relationship between obstructive sleep apnoea and erectile dysfunction: An underdiagnosed link? A prospective cross-sectional study.

This cross-sectional study aimed to investigate the prevalence and clinical characteristics of erectile dysfunction in patients with obstructive sleep apnoea. We enrolled 133 male patients with suspected obstructive sleep apnoea. Ear, nose and throat evaluation, laboratory tests, body mass index, Epworth sleepiness scale, 5-international index of erectile function, overnight ambulatory polygraphy and drug-induced sleep endoscopy patterns were assessed. Eighty patients reported obstructive sleep apnoea. 60% (n = 48) reported erectile dysfunction. Statistically significant correlations were found between 5-International Index of Erectile Function and age, hypertension, diabetes, Epworth sleepiness scale, apnoea-hypopnea index score, O2 saturation-nadir, and oxygen desaturation index. Age, diabetes and O2 saturation-nadir were independent predictors of erectile function. Epworth sleepiness scale, apnoea-hypopnea index score, O2 saturation-nadir, oxygen desaturation index and albumin were higher compared to patients without erectile dysfunction. No statistically significant differences were reported for drug-induced sleep endoscopy patterns and erectile dysfunction. Patients with obstructive sleep apnoea were at significant risk of having erectile dysfunction. Males with obstructive sleep apnoea should be investigated for erectile dysfunction.

Bilateral deficit magnitude increases with velocity during a half-squat exercise.

Movement velocity has been viewed as one of the bilateral deficit (BLD) determinants. This research tested the velocity effect on BLD during a half-squat exercise. The role of muscle excitation in BLD was also assessed. BLD amplitude was assessed in 12 male soccer players while performing a half-squat exercise with incremental load. During the exercise's pushing phase, the average force and velocity were measured in bilateral and unilateral conditions to provide the bilateral index (BI) at each interpolated velocity. The vastus lateralis and medialis excitation was assessed during the exercise by calculating the surface electromyography signal root mean square (sEMGRMS). The BI for sEMGRMS (sEMG BI) was calculated. The theoretical maximum force (F0) and velocity (v0) were also determined. F0 was +43 (28)% in bilateral compared with unilateral conditions (p < 0.001), whereas v0 was similar in both conditions (p = 0.386). The BI magnitude rose with the increase in velocity from -34 (7)% at 50%v0 to -70 (17)% at 90%v0 (p 0.03-<0.001), whereas no sEMG BI occurred (p: 0.07-0.991 in both muscles). The study reported velocity-dependent changes in the BLD amplitude, with the largest BLD amplitudes occurring at the highest velocities. This behaviour could provide useful information for setting specific contraction velocities to exploit/limit the BLD amplitude as a possible training stimulus.

The three-dimensional reconstruction of an Achilles tendon rupture in a professional football player reveals a multiplanar injury mechanism.

Achilles tendon rupture (ATR) is a rare although very serious injury for football players; currently, studies on ATR in football are scant. This case report intends to firstly describe the situational pattern and three-dimensional mechanism of the ATR injury occurred to a professional football player during the last UEFA 2020 Championship. To reconstruct the full 3D joint kinematics throughout the injury action, the model-based image-matching technique was used. The key findings were: (i) ATR injury combined a sudden ankle dorsiflexion action with an internal plantarflexion moment while performing a crossover cut at high speed; (ii) a multi-planar loading occurred during the push-off phase.Level of evidence V.

Training elite youth soccer players: area per player in small-sided games to replicate the match demands.

The aim was to determine the area per player (ApP, m2 × player) in small- or large-sided games to replicate the official match demands in elite youth soccer players. Two hundred and twenty-eight players (U15 = 36, U16 = 48, U17 = 49, U18 = 37 and U19 = 58) were monitored during both training (12 183 individual samples) and matches (683 individual samples) across five seasons. Relative (m × min-1) total (TD), high-speed running (HSR), very high-speed running (VHSR), sprint and acceleration/deceleration (Acc/Dec) distance were collected. Between-category and between-position comparisons were performed. Area per player was moderately correlated (P < 0.05) with TD (r = 0.401), large (r = 0.621) with HSR, and very largely with VHSR (r = 0.744) and sprint (r = 0.723). An inverse small (r = -0.232; P = 0.039) correlation for Acc/Dec was found. The area per player to replicate the match demands was 158 ± 18, 182 ± 32, 197 ± 37, 212 ± 42 and 156 ± 25 m2 × player for TD, HSR, VHSR, sprint and Acc/Dec, respectively. Moderate to very large (ES: 0.79 to 4.66) differences in the area per player across metrics were observed, with sprint > VHSR > HSR > TD = Acc/Dec. Trivial to very large (ES: 0.01 to 2.67) between-category differences in area per player across the same metric were found, with U15 and U16 requiring a larger area per player than other age categories. These findings may help practitioners to recreate the desired external load outcomes with regards to positional match-play demands using specific area per player in small- or large-sided games in youth elite soccer players from U15 to U19.

The distribution of match activities relative to the maximal intensities in elite soccer players: implications for practice.

To determine the distribution of match-activities relative to maximum-intensities during official match in elite soccer players. One hundred and forty-eight Italian Serie A soccer players were monitored during 46 official matches (680 individual-samples). Total distance (TD), high-speed running (HSR), very high-speed running (VHSR), sprint, acceleration and deceleration were calculated. Maximum-intensities (1-minpeak) were used as the reference value to determine the distribution of relative intensity across the whole-match demands (90-minavg). Time and distance higher than 90-minavg (>90-minavg) were also calculated. The relative (m·min-1) 90-minavg vs1-minpeak was 59.6(4.4)% for TD, 26.2(4.4)% for HSR, 16.0(3.5)% for VHSR, 9.3(2.3)% for sprint, 19.2(4.6)% for acceleration and 15.4(5.2)% for deceleration. Total distance covered >90-minavg was ~61.4(5.0)% for TD, ~68.6(1.9)% for HSR, ~80.2(1.3)% for VHSR, ~95.7(0.4)% for sprint, ~75.5(1.3)% for acceleration and ~64.0(2.6)% for deceleration. With the exception of small [ES: 0.50 (0.26 to 0.73)] difference for acceleration, the relative distance >90-minavg was largely to very largely (ES: 1.64 to 7.78) higher (P< 0.05) than the 90-minavg for each metric. While no between-position difference (P> 0.05) was found for total minutes >90-minavg, between-position differences (P< 0.05) for the total distance >90-minavg were retrieved across each metric. The distribution of the activities relative to maximal intensities could assist coaches for soccer training prescriptions.

Testing protocol affects the velocity at VO2max in semi-professional soccer players.

To compare three different protocols to assess the velocity associated with the maximal oxygen uptake (Vmax) in soccer players. Sixteen semi-professional soccer players performed three maximum incremental tests on treadmill: two continuous protocols [1 km·h-1·min-1 (CP1); and 1 km·h-1 every 2 min (CP2)], and one discontinuous (DP) protocol to determine Vmax, maximum oxygen uptake (VO2max) and oxygen cost of running (i.e., the slope of the VO2 vs velocity relationship at submaximal exercise). Vmax was higher in CP1> CP2> DP (19.4 ± 1.7, 17.4 ± 1.2, 16.1 ± 1.1 km·h-1 for CP1, CP2, and DP, respectively; P < 0.05 ES: 0.09 to 3.36). No difference in VO2max was found between CP1, CP2 and DP (P > 0.05). Oxygen cost of running showed between-protocol differences (CP1> CP2> DP; P < 0.05; ES: 0.28 to 3.30). Vmax was higher when determined using continuous vs discontinuous protocols due to the greater overestimation in oxygen cost of running. Such differences in Vmax should be considered to optimize acute physiological responses during high-intensity running activities.

No effect of passive stretching on neuromuscular function and maximum force-generating capacity in the antagonist muscle.

PURPOSE: The present study investigated whether or not passive stretching increases the force-generating capacity of the antagonist muscle, and the possible neuromuscular mechanisms behind. METHODS: To this purpose, the neuromuscular function accompanying the force-generating capacity was assessed in 26 healthy male volunteers after passive stretching and in a control session. Before and after passive intermittent static stretching of the plantar flexors consisting of five sets × 45 s + 15 s-rest, maximum voluntary isometric contraction (MVC) and surface electromyographic root mean square (sEMG RMS) were measured in the tibialis anterior (the antagonist muscle). Additionally, evoked V wave, H-reflex, and M wave were elicited by nerve stimulation at rest and during MVC. Ankle range of motion (ROM) and plantar flexors MVC and EMG RMS were measured to check for the effectiveness of the stretching manoeuvre. RESULTS: No change in MVC [p = 0.670; effect size (ES) - 0.03] and sEMG RMS/M wave during MVC (p = 0.231; ES - 0.09) was observed in the antagonist muscle after passive stretching. Similarly, no change in V wave (p = 0.531; ES 0.16), H-reflex at rest and during MVC (p = 0.656 and 0.597; ES 0.11 and 0.23, respectively) and M wave at rest and during MVC (p = 0.355 and 0.554; ES 0.04 and 0.01, respectively) was observed. An increase in ankle ROM (p < 0.001; ES 0.55) and a decrease in plantar flexors MVC (p < 0.001; ES - 1.05) and EMG RMS (p < 0.05; ES - 1.72 to - 0.13 in all muscles) indicated the effectiveness of stretching protocol. CONCLUSION: No change in the force-generating capacity and neuromuscular function of the antagonist muscle after passive stretching was observed.

Training status affects between-protocols differences in the assessment of maximal aerobic velocity.

PURPOSE: Continuous incremental protocols (CP) may misestimate the maximum aerobic velocity (Vmax) due to increases in running speed faster than cardiorespiratory/metabolic adjustments. A higher aerobic capacity may mitigate this issue due to faster pulmonary oxygen uptake ([Formula: see text]O2) kinetics. Therefore, this study aimed to compare three different protocols to assess Vmax in athletes with higher or lower training status. METHODS: Sixteen well-trained runners were classified according to higher (HI) or lower (LO) [Formula: see text]O2max [Formula: see text]O2-kinetics was calculated across four 5-min running bouts at 10 km·h-1. Two CPs [1 km·h-1 per min (CP1) and 1 km·h-1 every 2-min (CP2)] were performed to determine Vmax [Formula: see text]O2max, lactate-threshold and submaximal [Formula: see text]O2/velocity relationship. Results were compared to the discontinuous incremental protocol (DP). RESULTS: Vmax, [Formula: see text]O2max, [Formula: see text]CO2 and VE were higher [(P < 0.05,(ES:0.22/2.59)] in HI than in LO. [Formula: see text]O2-kinetics was faster [P < 0.05,(ES:-2.74/ - 1.76)] in HI than in LO. [Formula: see text]O2/velocity slope was lower in HI than in LO [(P < 0.05,(ES:-1.63/ - 0.18)]. Vmax and [Formula: see text]O2/velocity slope were CP1 > CP2 = DP for HI and CP1 > CP2 > DP for LO. A lower [P < 0.05,(ES:0.53/0.75)] Vmax-difference for both CP1 and CP2 vs DP was found in HI than in LO. Vmax-differences in CP1 vs DP showed a large inverse correlation with Vmax, [Formula: see text]O2max and lactate-threshold and a very large correlation with [Formula: see text]O2-kinetics. CONCLUSIONS: Higher aerobic training status witnessed by faster [Formula: see text]O2 kinetics led to lower between-protocol Vmax differences, particularly between CP2 vs DP. Faster kinetics may minimize the mismatch issues between metabolic and mechanical power that may occur in CP. This should be considered for exercise prescription at different percentages of Vmax.

The effects of 12 weeks of static stretch training on the functional, mechanical, and architectural characteristics of the triceps surae muscle-tendon complex.

PURPOSE: We investigated the effects of 12 weeks of passive static stretching training (PST) on force-generating capacity, passive stiffness, muscle architecture of plantarflexor muscles. METHODS: Thirty healthy adults participated in the study. Fifteen participants (STR, 6 women, 9 men) underwent 12-week plantarflexor muscles PST [(5 × 45 s-on/15 s-off) × 2exercises] × 5times/week (duration: 2250 s/week), while 15 participants (CTRL, 6 women, 9 men) served as control (no PST). Range of motion (ROM), maximum passive resistive torque (PRTmax), triceps surae architecture [fascicle length, fascicle angle, and thickness], passive stiffness [muscle-tendon complex (MTC) and muscle stiffness], and plantarflexors maximun force-generating capacity variables (maximum voluntary contraction, maximum muscle activation, rate of torque development, electromechanical delay) were calculated Pre, at the 6th (Wk6), and the 12th week (Wk12) of the protocol in both groups. RESULTS: Compared to Pre, STR ROM increased (P < 0.05) at Wk6 (8%) and Wk12 (23%). PRTmax increased at Wk12 (30%, P < 0.05), while MTC stiffness decreased (16%, P < 0.05). Muscle stiffness decreased (P < 0.05) at Wk6 (11%) and Wk12 (16%). No changes in triceps surae architecture and plantarflexors maximum force-generating capacity variables were found in STR (P > 0.05). Percentage changes in ROM correlated with percentage changes in PRTmax (ρ = 0.62, P = 0.01) and MTC stiffness (ρ = - 0.78, P = 0.001). In CTRL, no changes (P > 0.05) occurred in any variables at any time point. CONCLUSION: The expected long-term PST-induced changes in ROM were associated with modifications in the whole passive mechanical properties of the ankle joint, while maximum force-generating capacity characteristics were preserved. 12 weeks of PST do not seem a sufficient stimulus to induce triceps surae architectural changes.

Effect of formation, ball in play and ball possession on peak demands in elite soccer.

This study examined the most demanding passages of match play (MDP) and the effects of playing formation, ball-in-play (BiP) time and ball possession on the 1-min peak (1-minpeak) demand in elite soccer. During 18 official matches, 305 individual samples from 223 Italian Serie A soccer players were collected. MDP and 1-minpeak were calculated across playing position (central defenders, wide defenders, central midfielders, wide midfielders, wide forwards and forwards). Maximum relative (m·min-1) total distance (TD), high-speed running (HSR), very high-speed running (VHSR), sprint (SPR), acceleration/deceleration (Acc/Dec), estimated metabolic power (Pmet) and high-metabolic load (HML) distance were calculated across different durations (1-5, 10, 90 min) using a rolling method. Additionally, 1-minpeak demand was compared across playing formation (3-4-1-2, 3-4-2-1, 3-5-2, 4-3-3, 4-4-2), BiP and ball/no-ball possession cycles. MDP showed large to verylarge [effect-size (ES): 1.20/4.06] differences between 1-minpeak vs all durations for each parameter. In 1-minpeak, central midfielders and wide midfielders achieved greater TD and HSR (ES:0.43/1.13) while wide midfielders and wide forwards showed greater SPR and Acc/Dec (ES:0.30/1.15) than other positions. For VHSR, SPR and Acc/Dec 1-minpeak showed fourfold higher locomotor requirements than 90-min. 1-minpeak for Acc/Dec was highest in 4-3-3 for forwards, central and wide midfielders. 1-minPeak was lower during peak BiP (BiPpeak) for HSR, VHSR and Acc/Dec (ES: -2.57/-1.42). Comparing with vs without ball possession, BiPpeak was greater (ES: 0.06/1.48) in forwards and wide forwards and lower (ES: -2.12/-0.07) in central defenders and wide defenders. Positional differences in MDP, 1-minpeak and BiPpeak were observed. Soccer-specific drills should account for positional differences when conditioning players for the peak demands. This may help practitioners to bridge the training/match gap.