Optimization of cerebral oxygenation based on regional cerebral oxygen saturation monitoring during carotid endarterectomy: A Phase III multicenter, double-blind randomized controlled trial.

BACKGROUND: Whether the optimization of cerebral oxygenation based on regional cerebral oxygen saturation (rSO2) monitoring reduces the occurrence of cerebral ischemic lesions is unknown. METHODS: This multicenter, randomized, controlled trial recruited adults admitted for scheduled carotid endarterectomy. Patients were randomized between the standard of care or optimization of cerebral oxygenation based on rSO2 monitoring using near-infrared spectroscopy. In the intervention group, in case of a decrease in rSO2 in the intervention, the following treatments were sequentially recommended: (1) increasing oxygenotherapy, (2) reducing the tidal volume, (3) legs up-raising, (4) performing a fluid challenge and (5) initiating vasopressor support. The primary endpoint was the number of new cerebral ischemic lesions detected using magnetic resonance imaging pre- and postoperatively. Secondary endpoints included new neurological deficits and mortality on day 120 after surgery. RESULTS: Among the 879 patients who were randomized, 665 (75.7%) were men. There was no statistically significant difference between groups for the mean number of new cerebral ischemic lesions per patient up to 3 days after surgery: 0.35 (±1.05) in the standard group vs. 0.58 (±2.83), in the NIRS group; mean difference, 0.23 [95% CI, -0.06 to 0.52]; estimate, 0.22 [95% CI, -0.06 to 0.50]. New neurological deficits up to day 120 after hospital discharge were not different between the groups: 15 (3,39%) in the standard group vs. 42 (5,49%) in the NIRS group; absolute difference, 2,10 [95% CI, -0,62 to 4,82]. There was no significant difference between groups for the median [IQR] hospital length of stay: 4.0 [4.0 to 6.0] in the standard group vs 5.0 [4.0-6.0] in the NIRS group; mean difference, -0.11 [95% CI, -0.65 to 0.44]. The mortality rate on day 120 was not different between the standard group (0.68%) vs. the NIRS group (0.92%); absolute difference = 0.24% [95% CI, -0.94 to 1.41]. CONCLUSIONS: Among patients undergoing carotid endarterectomy, optimization of cerebral oxygenation based on rSO2 did not reduce the occurrence of cerebral ischemic lesions postoperatively compared with controlled hypertensive therapy. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01415648.

A Qualitative Study of 11 World-Class Team-Sport Athletes' Experiences Answering Subjective Questionnaires: A Key Ingredient for 'Visible' Health and Performance Monitoring?

BACKGROUND: Athlete monitoring trends appear to be favouring objective over subjective measures. One reason of potentially several is that subjective monitoring affords athletes to give dishonest responses. Indeed, athletes have never been systematically researched to understand why they are honest or not. OBJECTIVE: Because we do not know what motivates professional athletes to be honest or not when responding to subjective monitoring, our objective is to explore the motives for why the athlete may or may not respond honestly. METHODS: A qualitative and phenomenological approach was used, interviewing 11 world-class team-sport athletes (five women, six men) about their experiences when asked to respond to subjective monitoring questionnaires. Interview transcripts were read in full and significant quotations/statements extracted. Meanings were formulated for each interviewees' story and assigned codes. Codes were reflected upon and labelled as categories, with similar categories grouped into an overall theme. Themes were examined, articulated, re-interpreted, re-formulated, and written as a thematic story, drawing on elements reported from different athletes creating a blended story, allowing readers a feel for what it is like to live the experience. RESULTS: Overall, four key themes emerged: (i) pursuit of the ideal-self, (ii) individual barriers to athlete engagement, (iii) social facilitators to athlete engagement; and (iv) feeling compassion from performance staff. CONCLUSIONS: Our main insight is that athletes' emotions play a major role in whether they respond honestly or not, with these emotions being driven at least in part by the performance staff asking the questions.

Football-specific extension of the IOC consensus statement: methods for recording and reporting of epidemiological data on injury and illness in sport 2020.

Several sports have published consensus statements on methods and reporting of epidemiological studies concerning injuries and illnesses with football (soccer) producing one of the first guidelines. This football-specific consensus statement was published in 2006 and required an update to align with scientific developments in the field. The International Olympic Committee (IOC) recently released a sports-generic consensus statement outlining methods for recording and reporting epidemiological data on injury and illness in sport and encouraged the development of sport-specific extensions.The Fédération Internationale de Football Association Medical Scientific Advisory Board established a panel of 16 football medicine and/or science experts, two players and one coach. With a foundation in the IOC consensus statement, the panel performed literature reviews on each included subtopic and performed two rounds of voting prior to and during a 2-day consensus meeting. The panel agreed on 40 of 75 pre-meeting and 21 of 44 meeting voting statements, respectively. The methodology and definitions presented in this comprehensive football-specific extension should ensure more consistent study designs, data collection procedures and use of nomenclature in future epidemiological studies of football injuries and illnesses regardless of setting. It should facilitate comparisons across studies and pooling of data.

Examination of the validity of the Injury-Psychological Readiness to Return to Sport (I-PRRS) scale in male professional football players: A worldwide study of 29 professional teams.

Perceived confidence is an important dimension of an athlete's psychological readiness to return-to-play. However, there is no established and validated tool to evaluate confidence in professional football. This study aimed to provide preliminary evaluation of the internal structure of the Injury-Psychological Readiness to Return-to-Sport scale (I-PRRS) in a cohort of injured male professional footballers. Over an 18-month period, 29 teams from 17 leagues participated. Players sustaining injuries eliciting ≥ 3 weeks' time-loss were recruited. Cross culturally adapted to 4 further languages, the I-PRRS was administered on two occasions: 1) day before returning-to-training and 2) day before returning-to-match-play. In total, 113 injuries were recorded with 96 completed I-PRRS data sets collected. Confirmatory factor analysis indicated the I-PRRS was a unidimensional scale, with all items measuring the same construct. The scale demonstrated good internal consistency (ω = .88). When examining longitudinal invariance of the I-PRRS across administration time-points, indices of model fit supported scalar invariance. There was preliminary evidence of good internal structure for the I-PRRS in professional male footballers. However, before further research involving the I-PRRS can be endorsed, efforts to confirm or refute empirical developments pertaining to psychological readiness are necessary.

Recovery During a Congested Schedule and Injury in Professional Football.

PURPOSE: To analyze the relationships between the recovery kinetics experienced by professional football players and noncontact injury. METHODS: A cohort of 46 professional football players (age 24.2 [4.7] y) from the same team (French Ligue 1) was monitored each day between matches when the team played twice a week. The recovery monitoring procedure was implemented after 38 matches and included some questionnaires: duration of sleep, Hooper scale (quality of sleep, level of stress, fatigue, and muscle soreness), perceived recovery status scale, creatine kinase concentrations, a countermovement jump, and an isometric force test. Noncontact injuries were collected during these periods. RESULTS: Noncontact injuries were associated with perceived fatigue and muscle soreness 2 days (relative risk [RR] = 1.89 and 1.48, respectively) and 3 days following the matches (RR = 2.08 and 2.08, respectively). An increase of sleep quantity during the 2 nights following a match was significantly associated with a lower RR (RR = 0.65), as well as a lower decrement score on the isometric force test on each of the 3 days after the matches (RR = 0.97, RR = 0.99, and RR = 0.97, respectively). No other association was reported for the variables sleep quality, stress, perceived recovery, creatine kinase concentrations, countermovement jump, and noncontact injuries. CONCLUSION: During a congested schedule, implementing a recovery monitoring protocol including questionnaires about fatigue, muscle soreness, quantity of sleep, and a physical test of isometric force could help practitioners prevent injuries.

Biochemical Markers and Wellness Status During a Congested Match Play Period in Elite Soccer Players.

OBJECTIVES: To analyze biochemical markers, wellness status, and physical fitness in elite soccer players in relation to changes in training and match exposure during a congested period of match play. METHODS: Fourteen elite soccer players were evaluated 3 times (T1, T2, and T3) over 12 weeks (T1-T2: 6-wk regular period of match play and T2-T3: 6-wk congested period of match play). Players performed vertical jump tests, repeated shuttle sprint ability test, and the Yo-Yo Intermittent Recovery Test at T1, T2, and T3. Plasma C-reactive protein, creatinine, and creatine kinase were analyzed at T1, T2, and T3. Wellness status was measured daily using the Hopper questionnaire (delayed onset of muscle soreness, stress, fatigue, and sleep quality). Training session rating of perceived exertion was also recorded on a daily basis. RESULTS: A significant increase was found in stress, fatigue, delayed onset of muscle soreness scores, and Hopper index during the congested period (between T2 and T3) compared with the regular period (between T1 and T2) (.001 < P < .008, 0.8 < ES < 2.3). Between T2 and T3, significant relationships were found between the percentage variations (Δ%) of C-reactive protein, and Δ% of creatine kinase with the Hopper Index, and the Δ% of fatigue score. In addition, the Δ% of fatigue score and Δ% of delayed onset of muscle soreness score correlated with Δ% Yo-Yo Intermittent Recovery Test and Δ% best of repeated shuttle sprint ability test (.49 < r < P < .01). CONCLUSIONS: An intensive period of congested match play significantly compromised elite soccer players' physical fitness and wellness status. Elite soccer players' wellness status reflects declines in physical fitness during this period while biochemical changes do not.

Individual versus collective debriefing after interprofessional training course simulation: The randomised DEBRIEF-SIM trial.

INTRODUCTION: Debriefing is a critical phase in simulation-based education that is extremely time-consuming for the instructors. The aim of the study was to assess whether a collective debriefing was non-inferior to an individual debriefing to improve learning outcomes after a simulation session. METHODS: This randomised controlled multicentre non-inferiority study included pairs comprising one resident and one student nurse in anaesthesia. Each pair underwent two sessions of a simulated life-threatening emergency held at a 6-week interval. Six participant pairs underwent simulation sessions every half-day of training. The debriefing performed after the first session was either individual (1 debriefing by pair; individual group) or collective (1 debriefing by 6 pairs; collective group). The primary outcome was the evolution of a 34-parameter technical skill score (Delta-TSS-34) between the two simulation sessions. The non-inferiority margin was 5. The change in the Anaesthetists' Non-Technical Skills score (Delta-ANTS), and the debriefing duration per participant pair were secondary endpoint measures. RESULTS: Respectively 23 and 21 pairs were included in the collective and individual groups. Delta-TSS-34 was non-inferior in the collective group compared to the individual group (mean intergroup difference [95% confidence interval]: 2.71 [0.44-4.98]). Delta-ANTS did not significantly differ between the two groups (median [interquartile range]: 22 [10-37] versus 25 [17-35], p = 0.57; respectively in the collective and individual groups). The debriefing duration per participant pair was significantly lower in the collective group (10 [10-11] min versus 27 [25-28] min; p < 0.001). CONCLUSION: Collective debriefing was non-inferior to individual debriefing to improve learning outcomes after simulation of medical emergencies and allows a significant reduction in the time dedicated to the debriefing.

UEFA expert group statement on nutrition in elite football. Current evidence to inform practical recommendations and guide future research.

Football is a global game which is constantly evolving, showing substantial increases in physical and technical demands. Nutrition plays a valuable integrated role in optimising performance of elite players during training and match-play, and maintaining their overall health throughout the season. An evidence-based approach to nutrition emphasising, a 'food first' philosophy (ie, food over supplements), is fundamental to ensure effective player support. This requires relevant scientific evidence to be applied according to the constraints of what is practical and feasible in the football setting. The science underpinning sports nutrition is evolving fast, and practitioners must be alert to new developments. In response to these developments, the Union of European Football Associations (UEFA) has gathered experts in applied sports nutrition research as well as practitioners working with elite football clubs and national associations/federations to issue an expert statement on a range of topics relevant to elite football nutrition: (1) match day nutrition, (2) training day nutrition, (3) body composition, (4) stressful environments and travel, (5) cultural diversity and dietary considerations, (6) dietary supplements, (7) rehabilitation, (8) referees and (9) junior high-level players. The expert group provide a narrative synthesis of the scientific background relating to these topics based on their knowledge and experience of the scientific research literature, as well as practical experience of applying knowledge within an elite sports setting. Our intention is to provide readers with content to help drive their own practical recommendations. In addition, to provide guidance to applied researchers where to focus future efforts.

The Interplay Between Plasma Hormonal Concentrations, Physical Fitness, Workload and Mood State Changes to Periods of Congested Match Play in Professional Soccer Players.

BACKGROUND: The regular assessment of hormonal and mood state parameters in professional soccer are proposed as good indicators during periods of intense training and/or competition to avoid overtraining. OBJECTIVE: The aim of this study was to analyze hormonal, psychological, workload and physical fitness parameters in elite soccer players in relation to changes in training and match exposure during a congested period of match play. METHODS: Sixteen elite soccer players from a team playing in the first Tunisian soccer league were evaluated three times (T1, T2, and T3) over 12 weeks. The non-congested period of match play was from T1 to T2, when the players played 6 games over 6 weeks. The congested period was from T2 to T3, when the players played 10 games over 6 weeks. From T1 to T3, players performed the Yo-Yo intermittent recovery test level 1 (YYIR1), the repeated shuttle sprint ability test (RSSA), the countermovement jump test (CMJ), and the squat jump test (SJ). Plasma Cortisol (C), Testosterone (T), and the T/C ratio were analyzed at T1, T2, and T3. Players had their mood dimensions (tension, depression, anger, vigor, fatigue, confusion, and a Total Mood Disturbance) assessed through the Profile of Mood State questionnaire (POMS). Training session rating of perceived exertion (sRPE) was also recorded on a daily basis in order to quantify internal training load and elements of monotony and strain. RESULTS: Significant performance declines (T1 < T2 < T3) were found for SJ performance (p = 0.04, effect size [ES] ES1 - 2 = 0.15-0.06, ES2 - 3 = 0.24) from T1 to T3. YYIR1 performance improved significantly from T1 to T2 and declined significantly from T2 to T3 (p = 0.001, ES1 - 2 = 0.24, ES2 - 3 = -2.54). Mean RSSA performance was significantly higher (p = 0.019, ES1 - 2 = -0.47, ES2 - 3 = 1.15) in T3 compared with T2 and T1. Best RSSA performance was significantly higher in T3 when compared with T2 and T1 (p = 0.006, ES2 - 3 = 0.47, ES1 - 2 = -0.56), but significantly lower in T2 when compared with to T1. T and T/C were significantly lower in T3 when compared with T2 and T1 (T: p = 0.03, ES3 - 2 = -0.51, ES3 - 1 = -0.51, T/C: p = 0.017, ES3 - 2 = -1.1, ES3 - 1 = -1.07). Significant decreases were found for the vigor scores in T3 when compared to T2 and T1 (p = 0.002, ES1 - 2 = 0.31, ES3 - 2 = -1.25). A significant increase was found in fatigue scores in T3 as compared to T1 and T2 (p = 0.002, ES1 - 2 = 0.43, ES2 - 3 = 0.81). A significant increase was found from T1 < T2 < T3 intension score (p = 0.002, ES1 - 2 = 1.1, ES2 - 3 = 0.2) and anger score (p = 0.03, ES1 - 2 = 0.47, ES2 - 3 = 0.33) over the study period. Total mood disturbance increased significantly (p = 0.02, ES1 - 2 = 0.91, ES2 - 3 = 1.1) from T1 to T3. Between T1-T2, significant relationships were observed between workload and changes in T (r = 0.66, p = 0.003), and T/C ratio (r = 0.62, p = 0.01). There were significant relationships between performance in RSSAbest and training load parameters (workload: r = 0.52, p = 0.03; monotony: r = 0.62, p = 0.01; strain: r = 0.62, p = 0.009). Between T2-T3, there was a significant relationship between Δ% of total mood disturbance and Δ% of YYIR1 (r = -0.54; p = 0.04), RSSAbest (r = 0.58, p = 0.01), SJ (r = -0,55, p = 0.01), T (r = 0.53; p = 0.03), and T/C (r = 0.5; p = 0.04). CONCLUSION: An intensive period of congested match play significantly compromised elite soccer players' physical and mental fitness. These changes were related to psychological but not hormonal parameters; even though significant alterations were detected for selected measures. Mood monitoring could be a simple and useful tool to determine the degree of preparedness for match play during a congested period in professional soccer.

Exercise-Based Strategies to Prevent Muscle Injury in Elite Footballers: A Systematic Review and Best Evidence Synthesis.

BACKGROUND: Exercise-based strategies are used to prevent muscle injuries in football and studies on different competitive-level populations may provide different results. OBJECTIVES: To evaluate the effectiveness of exercise-based muscle injury prevention strategies in adult elite football. METHODS: A systematic search was conducted in PubMed (MEDLINE), Web of Science, Cochrane Library, and SPORTDiscuss (EBSCO). We considered only elite adult (> 16 year-old) football players with no distinction for gender; the intervention to be any exercise/s performed with the target to prevent lower-limb muscle injuries; the comparison to be no injury prevention exercise undertaken; the outcome to be the number of injuries, injury incidence, and severity. We searched systematic reviews, randomized-controlled trials (RCTs), and non-randomized-controlled trials (NRCTs), limited for English language. Risk of bias was assessed using the Risk of Bias in Systematic Reviews tool, the Cochrane Collaboration's Tool for assessing risk of bias in RCTs, and the Risk of Bias in NRCTs of Interventions tool. RESULTS: 15 studies were included. Three systematic reviews showed inconsistent results, with one supporting (high risk of bias) and two showing insufficient evidence (low risk of bias) to support exercise-based strategies to prevent muscle injuries in elite players. Five RCTs and seven NRCTs support eccentric exercise, proprioception exercises, and a multi-dimensional component to an injury prevention program; however, all were deemed to be at high/critical risk of bias. Only one RCT was found at low risk of bias and supported eccentric exercise for preventing groin problems. CONCLUSION: We found limited scientific evidence to support exercise-based strategies to prevent muscle injury in elite footballers. TRIAL REGISTRATION NUMBER: PROSPERO CRD42017077705.

Return-to-Play Practices Following Hamstring Injury: A Worldwide Survey of 131 Premier League Football Teams.

PURPOSE: Return-to-play (RTP) is an on-going challenge in professional football. Return-to-play related research is increasing. However, it is unknown to what extent the recommendations presented within research are being implemented by professional football teams, and where there are gaps between research and practice. The purposes of this study were (1) to determine if premier-league football teams worldwide follow a RTP continuum, (2) to identify RTP criteria used and (3) to understand how RTP decision-making occurs in applied practice. METHODS: We sent a structured online survey to practitioners responsible for the RTP programme in 310 professional teams from 34 premier-leagues worldwide. The survey comprised four sections, based on hamstring muscle injury: (1) criteria used throughout RTP phases, (2) the frequency with which progression criteria were achieved, (3) RTP decision-making process and (4) challenges to decision-making. RESULTS: One-hundred and thirty-one teams responded with a completed survey (42%). One-hundred and twenty-four teams (95%) used a continuum to guide RTP, assessing a combination of clinical, functional and psychological criteria to inform decisions to progress. One-hundred and five (80%) teams reported using a shared decision-making approach considering the input of multiple stakeholders. Team hierarchy, match- and player-related factors were common challenges perceived to influence decision-making. CONCLUSIONS: General research recommendations for RTP and the beliefs and practices of practitioners appear to match with, the majority of teams assessing functional, clinical and psychological criteria throughout a RTP continuum to inform decision-making which is also shared among key stakeholders. However, specific criteria, metrics and thresholds used, and the specific involvement, dynamics and interactions of staff during decision-making are not clear.

The influence of playing position in soccer on the recovery kinetics of cognitive and physical performance.

BACKGROUND: The physical activity and playing actions performed during a soccer match vary according to player position. The aim of the present study was to analyze the recovery kinetics of cognitive performance, physical performance and subjective ratings after a competitive soccer match. METHODS: Eight goalkeepers and eight outfield players played in the match with data collected before, 45 min, 24 h and 48 h after the match. Subjective ratings, Vienna Reaction Test (reaction time, motor time), Vienna Determination Test (number of stimuli, number of correct responses), squat jump, countermovement jump and 6-s sprint were analyzed. RESULTS: No significant interaction between position and time was found for Vienna Reaction Test and Vienna Determination Test performance. No significant interaction between position and time was found for squat jump and countermovement jump but squat jump and countermovement jump significantly decreased (P<0.01) at 24 h. Countermovement jump performance was still significantly affected at 48h (P<0.05). A significant interaction between position and time (P<0.05) was found for 6-s sprint. Sprint performance was significantly reduced for outfield players only immediately after the match (P<0.01). There was no interaction effect of position and time on subjective ratings. A significant correlation was found between number of jumps and ball kicks performed during the match by goalkeepers and the change score in squat jump (r =-0.90; P<0.01) and countermovement jump (r =-0.90; P<0.01) observed at 48 h. CONCLUSIONS: Outfield players require a longer time than goalkeepers to recover sprint performance whilst cognitive function tested in the present study is not affected by the match whatever the position.

Effects of Neuromuscular Training on Agility Performance in Elite Soccer Players.

BACKGROUND: Agility in general and change-of-direction speed (CoD) in particular represent important performance determinants in elite soccer. OBJECTIVES: The objectives of this study were to determine the effects of a 6-week neuromuscular training program on agility performance, and to determine differences in movement times between the slower and faster turning directions in elite soccer players. MATERIALS AND METHODS: Twenty male elite soccer players from the Stade Rennais Football Club (Ligue 1, France) participated in this study. The players were randomly assigned to a neuromuscular training group (NTG, n = 10) or an active control (CG, n = 10) according to their playing position. NTG participated in a 6-week, twice per week neuromuscular training program that included CoD, plyometric and dynamic stability exercises. Neuromuscular training replaced the regular warm-up program. Each training session lasted 30 min. CG continued their regular training program. Training volume was similar between groups. Before and after the intervention, the two groups performed a reactive agility test that included 180° left and right body rotations followed by a 5-m linear sprint. The weak side was defined as the left/right turning direction that produced slower overall movement times (MT). Reaction time (RT) was assessed and defined as the time from the first appearance of a visual stimulus until the athlete's first movement. MT corresponded to the time from the first movement until the athlete reached the arrival gate (5 m distance). RESULTS: No significant between-group baseline differences were observed for RT or MT. Significant group x time interactions were found for MT (p = 0.012, effect size = 0.332, small) for the slower and faster directions (p = 0.011, effect size = 0.627, moderate). Significant pre-to post improvements in MT were observed for NTG but not CG (p = 0.011, effect size = 0.877, moderate). For NTG, post hoc analyses revealed significant MT improvements for the slower (p = 0.012, effect size = 0.897, moderate) and faster directions (p = 0.017, effect size = 0.968, moderate). CONCLUSION: Our results illustrate that 6 weeks of neuromuscular training with two sessions per week included in the warm-up program, significantly enhanced agility performance in elite soccer players. Moreover, improvements were found on both sides during body rotations. Thus, practitioners are advised to focus their training programs on both turning directions.

Subsequent Injury Risk Is Elevated Above Baseline After Return to Play: A 5-Year Prospective Study in Elite Australian Football.

BACKGROUND: The risk of sustaining a subsequent injury is elevated in the weeks after return to play (RTP) from an index injury. However, little is known about the magnitude, duration, and nature by which subsequent injury risk is increased. PURPOSE: To quantify and describe the risk of injury in a 12-week period after RTP from an index injury in Australian football players. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Injury data were collected from 79 players over 5 years at 1 Australian Football League club. Injuries were classified with the Orchard Sports Injury Classification System and by side of the body. Furthermore, injury severity was classified as time loss (resulting in ≥1 matches being missed) or non-time loss (no matches missed). Subsequent injury was categorized with the SIC-2.0 model and applied to the data set via an automated script. The probability of a time loss subsequent injury was calculated for in-season index injuries for each week of a 12-week period after RTP via a mixed effect logistic regression model. RESULTS: Subsequent injury risk was found to be highest in the week of RTP for both time loss injuries (9.4%) and non-time loss injuries (6.9%). Risk decreased with each week survived after RTP; however, it did not return to baseline risk of participation (3.6%). CONCLUSION: These findings demonstrate that athletes returning to play are at an increased risk of injury for a number of weeks, thus indicating the requirement for tertiary prevention strategies to ensure that they survive this period.

Muscle oxygenation induced by cycling exercise does not accelerate recovery kinetics following exercise-induced muscle damage in humans: A randomized cross-over study.

The aim of this study was to analyze the effects of inducing muscle oxygenation using an intermittent cycling exercise on recovery kinetics after exercise-induced muscle damage. Ten soccer players performed single-leg knee flexors exercise: 75 eccentric contractions. The day after, subjects performed an intermittent cycling exercise of 12 min (15 s work - 15 s rest) or recovered passively in a balanced and randomized cross-over design. Force, single and double-leg countermovement jumps, muscle soreness, perceived recovery and creatine kinase concentrations were assessed through a 72 h period. Oxygenation during cycling was assessed using Near Infrared Spectroscopy. Results showed an increase in knee flexors oxygenation using intermittent cycling (ΔHbO2 = 70.2 ± 19.8% ; ΔHHb = 68.2 ± 14.1%). Possibly small detrimental effect of cycling on eccentric force was found (ES = -0.58, 90% CI: -1.33 to 0.17). Small detrimental effects of cycling were found for soreness and perceived recovery. Implementing intermittent cycling exercise the day after muscle damage may be detrimental for recovery.

Workload and injury incidence in elite football academy players.

The aim of this study was to prospectively analyse the relationship between workloads and injury in elite football academy players. Elite football academy players (n = 122) from under-19 (U19) and under-21 (U21) of a professional football team competing in UEFA European Cups were followed during 5 seasons. Injuries were collected and absolute workload and workload ratios (4-weeks, 3-weeks, 2-weeks and week-to-week) calculated using a rolling days method with the help of the session Rate of Perceived Exertion. There was no association between absolute workload or workload ratio with the injury incidence in the U19. In the U21, the level of cumulative absolute workloads during 3-weeks (RR = 1.39, p = 0.026) and during 4-weeks (RR = 1.40, p = 0.019) were associated with an increase in injury. There was no association between workload ratio and injury in U21. The significant link between high cumulated 3-weeks and 4 weeks workloads and injury in U21 confirmed the requirement to monitor the internal subjective workload in U21 in order to prevent injury. Further studies exploring the relationships between workload and injury are required in football academy.

Active Versus Passive Recovery in High-Intensity Intermittent Exercises in Children: An Exploratory Study.

This study aimed to compare the effect of active recovery (AR) versus passive recovery (PR) on time to exhaustion and time spent at high percentages of peak oxygen uptake ( peakV˙O2 ) during short, high-intensity intermittent exercises in children. Twelve children (9.5 [0.7] y) underwent a graded test and 2 short, high-intensity intermittent exercises (15 s at 120% of maximal aerobic speed) interspersed with either 15 seconds of AR (50% of maximal aerobic speed) or 15-second PR until exhaustion. A very large effect (effect size = 2.42; 95% confidence interval, 1.32 to 3.52) was observed for time to exhaustion in favor of longer time to exhaustion with PR compared with AR. Trivial or small effect sizes were found for peakV˙O2 , peakHR, and peak ventilation between PR and AR, while a moderate effect in favor of higher average V˙O2 values (effect size = -0.87; 95% confidence interval, -1.76 to -0.01) was found using AR. The difference between PR and AR for the time spent above 80% (t80%) and 90% (t90%) of peakV˙O2 was trivial. Despite the shorter running duration in AR, similar t80% and t90% were spent with AR and PR. Time spent at a high percentage of peakV˙O2 may be attained by running 3-fold shorter using AR compared with using PR.