Colin Solomon

The contribution of energy systems during the upper body Wingate anaerobic test.

The purpose of this study was to measure the contribution of the aerobic, anaerobic lactic, and alactic systems during an upper body Wingate Anaerobic test (WAnT). Oxygen uptake and blood lactate were measured before, during, and after the WAnT and body composition analyzed by dual-energy X-ray absorptiometry. The contribution of the energy systems was 11.4% ± 1.4%, 60.3% ± 5.6%, and 28.3% ± 4.9% for the aerobic, anaerobic lactic, and alactic systems, respectively.

What’s in a game? A systems approach to enhancing performance analysis in football

Purpose Performance analysis (PA) in football is considered to be an integral component of understanding the requirements for optimal performance. Despite vast amounts of research in this area key gaps remain, including what comprises PA in football, and methods to minimise research-practitioner gaps. The aim of this study was to develop a model of the football match system in order to better describe and understand the components of football performance. Such a model could inform the design of new PA methods. Method Eight elite level football Subject Method Experts (SME’s) participated in two workshops to develop a systems model of the football match system. The model was developed using a first-of-its-kind application of Cognitive Work Analysis (CWA) in football. CWA has been used in many other non-sporting domains to analyse and understand complex systems. Result Using CWA, a model of the football match ‘system’ was developed. The model enabled identification of several PA measures not currently utilised, including communication between team members, adaptability of teams, playing at the appropriate tempo, as well as attacking and defending related measures. Conclusion The results indicate that football is characteristic of a complex sociotechnical system, and revealed potential new and unique PA measures regarded as important by SME’s, yet not currently measured. Importantly, these results have identified a gap between the current PA research and the information that is meaningful to football coaches and practitioners.

The Effect of Recovery Duration on Technical Proficiency during Small Sided Games of Football

The aim of this study was to determine the effect of increasing the duration of the recovery periods separating serial bouts of small sided games (SSG) of football on technical skills (TS). Twelve semi-professional footballers (mean ± SD; age 21 ± 3 years; VO2peak 64 ± 7 mL∙min∙kg−1; playing experience 15 ± 3 years) completed two SSG sessions, consisting of 3 vs. 3 players and 6 bouts of 2 min, separated by either 30 s recovery (REC-30) or 120 s recovery (REC-120). Sixteen TS, including passing, possession, and defensive related variables, and exercise intensity (heart rate, rating of perceived exertion, time motion descriptors) during the bouts were measured. Repeated measures ANOVA were used to determine differences between-conditions, for TS. The number of successful tackles was significantly higher, and the average time each team maintained possession was significantly lower in REC-120 compared to REC-30. There were no significant differences for all other TS variables, or exercise intensity measures between REC-30 and REC-120. Overall, a four-fold increase in the duration of recovery separating SSG bouts did not alter the technical skill execution of players. The experience and skill level of the players, combined with an apparent regulation of effort through pacing, may have assisted in the maintenance of technical skill execution.

The Dynamics of Speed Selection and Psycho-Physiological Load during a Mountain Ultramarathon

Background Exercise intensity during ultramarathons (UM) is expected to be regulated as a result of the development of psycho-physiological strain and in anticipation of perceived difficulties (duration, topography). The aim of this study was to investigate the dynamics of speed, heart rate and perceived exertion during a long trail UM in a mountainous setting. Methods Fifteen participants were recruited from competitors in a 106 km trail mountain UM with a total elevation gain and loss of 5870 m. Speed and gradient, heart rate (HR) and ratings of perceived exertion (dissociated between the general [RPEGEN] and knee extensor fatigue [RPEKE] and collected using a voice recorder) were measured during the UM. Self-selected speed at three gradients (level, negative, positive), HR, RPEGEN and RPEKE were determined for each 10% section of total event duration (TED). Results The participants completed the event in 18.3 ± 3.0 h, for a total calculated distance of 105.6 ± 1.8 km. Speed at all gradients decreased, and HR at all gradients significantly decreased from 10% to 70%, 80% and 90%, but not 100% of TED. RPEGEN and RPEKE increased throughout the event. Speed increased from 90% to 100% of TED at all gradients. Average speed was significantly correlated with total time stopped (r = -.772; p = .001; 95% confidence interval [CI] = -1.15, -0.39) and the magnitude of speed loss (r = .540; p = .038; 95% CI = -1.04, -0.03), but not with the variability of speed (r = -.475; p = .073; 95% CI = -1.00, 0.05). Conclusions Participants in a mountain UM event combined positive pacing strategies (speed decreased until 70–90% of TED), an increased speed in the last 10% of the event, a decrease in HR at 70–90% of TED, and an increase in RPEGEN and RPEKE in the last 30% of the event. A greater speed loss and less total time stopped were the factors associated with increased total performance. These results could be explained by theoretical perspectives of a complex regulatory system modulating motor drive in anticipation of perceived difficulties such as elevation changes.

The Effect of Recovery Duration on Vastus Lateralis Oxygenation, Heart Rate, Perceived Exertion and Time Motion Descriptors during Small Sided Football Games.

Purpose Small sided games (SSG) of football are an effective and efficient format to simultaneously train the physiological, technical, and tactical components of football. The duration of the recovery period between bouts of SSG will affect the physiological response to subsequent bouts. It was hypothesised that decreasing the duration of recovery periods separating serial SSG bouts would increase physiological, and perceptual responses, and decrease high speed running, and distance during SSG bouts. Methods Twelve experienced footballers (mean ± SD; age 21 ± 3 yrs; VO2peak 64 ± 7 ml·min·kg−1; playing experience 15 ± 3 yrs) completed two SSG sessions. Each SSG consisted of 3 vs. 3 players and 6 bouts of 2 min duration, with bouts separated by either 30 s recovery (REC-30) or 120 s recovery (REC-120). Deoxygenated haemoglobin (HHb) in the vastus lateralis (VL) (using near infrared spectroscopy), heart rate (HR) and time motion descriptors (TMD) (speed and distance) were measured continuously during the SSG sessions and perceived exertion (RPE) was measured for each bout. Results During the recovery periods, in REC-30 compared to REC-120, there was a significant (p < 0.05) main effect of a higher HHb and HR. During the bouts, in REC-30 compared to REC-120, there were no significant differences in HHb, HR, RPE, or TMD, but within both REC-30 and REC-120 there were significant increases as a function of bout number in RPE. Conclusions Although a four-fold increase in recovery period allowed a significant increase in the recovery of HHb and HR, this did not increase the physiological, and perceptual responses, or time motion descriptors during the bouts. These results could have been due to the regulation of effort (pacing), in these experienced players performing an exercise task to which they were well adapted.

Do inter-continental playing styles exist? Using social network analysis to compare goals from the 2016 EURO and COPA football tournaments knock-out stages

ABSTRACT The current study applied social network analysis (SNA) to the passing networks leading to goals scored by successful teams during the knock-out stages of the 2016 European football championships (EURO) and COPA America football championships (COPA). The aim was to test SNA as a method for analysing the structure of passes leading to goals and to determine whether there were any differences between the passing networks associated with goals scored, by countries of the two different continents. The passes leading to goals during each tournament were represented as networks and analysed using SNA metrics. Additional analysis examined the duration of the networks, and location on the pitch in which the passing network originated and where the goals were scored from. No differences were found for all SNA metrics, network duration, and pitch locations between teams from the 2016 EURO and COPA tournaments. Despite previously reported differences in style between European football and football in the Americas, the findings indicate that the passing networks immediately prior to goals scored by teams from both continents are similar.

The Effect of Active versus Passive Recovery Periods during High Intensity Intermittent Exercise on Local Tissue Oxygenation in 18 – 30 Year Old Sedentary Men

Purpose High intensity interval training (HIIT) has been proposed as a time-efficient format of exercise to reduce the chronic disease burden associated with sedentary behaviour. Changes in oxygen utilisation at the local tissue level during an acute session of HIIT could be the primary stimulus for the health benefits associated with this format of exercise. The recovery periods of HIIT effect the physiological responses that occur during the session. It was hypothesised that in sedentary individuals, local and systemic oxygen utilisation would be higher during HIIT interspersed with active recovery periods, when compared to passive recovery periods. Methods Twelve sedentary males (mean ± SD; age 23 ± 3 yr) completed three conditions on a cycle ergometer: 1) HIIT with passive recovery periods between four bouts (HIITPASS) 2) HIIT with active recovery periods between four bouts (HIITACT) 3) HIITACT with four HIIT bouts replaced with passive periods (REC). Deoxygenated haemoglobin (HHb) in the vastus lateralis (VL) and gastrocnemius (GN) muscles and the pre-frontal cortex (FH), oxygen consumption (VO2), power output and heart rate (HR) were measured continuously during the three conditions. Results There was a significant increase in HHb at VL during bouts 2 (p = 0.017), 3 (p = 0.035) and 4 (p = 0.035) in HIITACT, compared to HIITPASS. Mean power output was significantly lower in HIITACT, compared to HIITPASS (p < 0.001). There was a significant main effect for site in both HIITPASS (p = 0.029) and HIITACT (p = 0.005). There were no significant differences in VO2 and HR between HIITPASS and HIITACT. Conclusions The increase in HHb at VL and the lower mean power output during HIITACT could indicate that a higher level of deoxygenation contributes to decreased mechanical power in sedentary participants. The significant differences in HHb between sites indicates the specificity of oxygen utilisation.

Integrating communication and passing networks in football using social network analysis

ABSTRACT Background: Effective intra-team communication (ITC) is an important component for optimal team performance. Methods: In this study, an intra-team communication tool (ITCT) was used for players to report the amount of communication (ACOM) received, and the amount of perceived benefit to performance of that communication (BCOM). The ITCT was used to understand how a professional football team is connected, by ITC and passing, and the relationship between ITC and passing, using social network analysis (SNA). Results: The results indicated that the team was highly connected and cohesive for ITC, but less so for passing. In matches won compared to lost, passing connections were lower and ITC connections were higher. There were negative correlations between ITC and passing for the mean sociometric status values. For the SNA metrics, network edges were higher in matches won compared to drawn for BCOM. Cohesion was lower in drawn compared to won matches for BCOM, and lower compared to matches won and lost for passing. SMS was higher in matches won compared to lost for ACOM and BCOM, but was higher in matches lost compared to won for passing. Conclusions: The results could indicate that in matches when possession was increased, and ITC decreased, the team may coordinate implicitly, by relying on pre-existing knowledge of practiced playing structures. Whereas, in matches with low possession, increased levels of ITC may be required, due to the uncertainty associated with defending. However, further research is needed to confirm the current explanations of the results. This study has implications for the design of training practice.

Influence of exercise duration on cardiorespiratory responses, energy cost and tissue oxygenation within a 6 hour treadmill run

Purpose The physiological mechanisms for alterations in oxygen utilization (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}

A social network analysis of the goal scoring passing networks of the 2016 European Football Championships

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