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BACKGROUND: Physical activity and a healthy diet may delay the aging process and ultra-endurance exercise is an extreme form of physical activity. Telomeres are protective DNA sequences located at the ends of eukaryotic chromosomes which shorten as we age. OBJECTIVE: The aim of this study was to investigate the relationships of lifetime physical activity and diet with salivary cell telomere length in current ultra-endurance exercisers (n = 49; % female = 37, age range 26–74 years). METHODS: Physical activity and dietary intake were measured using the Lifetime Physical Activity and Diet Questionnaire (LPADQ) and salivary cell telomere length was measured using quantitative polymerase chain reaction. RESULTS: In this group of current ultra-endurance exercisers there was no relationship between lifetime physical activity or diet (according to food category scores) and telomere length. In contrast to the expected age-related decrease in telomere length, there was no relationship between age and telomere length (95% confidence interval [CI]: –38.86, 14.54, p = 0.359) in this group of current ultra-endurance exercisers. CONCLUSIONS: The relationships of lifetime physical activity and diet with telomere length remain uncertain. It is possible that lifetime physical activity (including ultra-endurance exercise) and lifetime diet may independently, or in combination, contribute to a decrease in the rate of age-related telomere shortening in current ultra-endurance exercisers.

Background: While the efficacy of sprint interval training (SIT) to provide positive health effects in inactive populations is established, feasibility is associated with enjoyment and safety, which are dependent on the acute physiological and perceptual responses. The recovery format likely influences physiological and perceptual responses that occur during and immediately after SIT. It was hypothesized that during SIT interspersed with active recovery periods, enjoyment and blood pressure (BP) values would be higher compared with passive recovery periods, in inactive participants. Methods: Twelve males (mean ± SD; age 23 ± 3 y) completed 3 exercise sessions on a cycle ergometer in a randomized order on separate days: (a) SIT with passive recovery periods between 4 bouts (SITPASS), (b) SIT with active recovery periods between 4 bouts (SITACT), and (c) SITACT with the 4 SIT bouts replaced with passive periods. BP was measured immediately after each bout and every 2 min during a 6 min recovery. Physical activity enjoyment was measured during postexercise recovery. Results: There were no significant differences in physical activity enjoyment or systolic BP between SITPASS and SITACT. Diastolic BP was lower during recovery in SITACT (P = 0.025) and SITPASS (P = 0.027), compared with resting BP. Furthermore, diastolic BP was lower after 6 min of recovery following SITPASS, compared with SITACT (P = 0.01). Conclusion: Exercise enjoyment and acute systolic BP responses were independent of SIT recovery format in inactive men. Reductions in diastolic BP were greater and more prolonged after SIT protocols that included passive recovery periods.

Determining the connectivity of team members in sport provides important information on team functioning. In soccer, teams that are highly connected via passing have been shown to be more successful compared to teams less connected via passing. In addition to passing connectivity, players are connected with each other via intra-team communication (ITC) through verbal instruction, and nonverbal cues. Despite ITC being a known component of effective teamwork to enhance strategy, efficiency, motivation and concentration, ITC of individual playing positions has not previously been measured during soccer games, nor has it been associated with passing connections in a performance context. In this study, the received ITC that was perceived to be beneficial to performance during 22 competitive professional soccer matches was measured, in conjunction with the passing connections between team members. In total, 526 ITC ratings were collected and analysed, and a total of 7,693 passes were analysed. From the ITC and passing measures, a player connectivity index (PCI) representing the coupling of ITC and passing, was developed to determine the overall connectivity of the individual playing positions. Social network analysis (SNA) centrality metrics were used to determine the connectivity of the playing positions. There were significant (p < .05) main effects between playing positions for beneficial ITC, passing, and the PCI for centrality metrics, indicating that different playing positions interact with other team members differently. Pairwise comparisons indicated significant differences between individual playing positions for ITC, passing and the PCI. The two central defenders and the two central defensive midfielders had the highest mean values for ITC, passing, and the PCI compared to the other playing positions. The current findings suggest that central defenders and central defensive midfielders are positioned tactically to be highly involved in the build-up of passing moves, and to deliver beneficial task related information to team members. These findings have implications for performance analysis, coaches, and for talent identification.

Physical exercise requiring oxidative energy transfer increases pulmonary ventilation (VE). In an air polluted environment, the exercise-induced increase in VE increases the volume of toxic gases and number of toxic particles to which the pulmonary system is exposed. Using a respiratory air-filtering device (RAFD) during exercise decreases exposure to inhaled toxic gases and particles. However, a RAFD creates external resistance to inspiration and expiration which could decrease pulmonary muscle function and pulmonary volumes, and creates an external mechanical dead-space which produces fractional rebreathing which could increase pulmonary flowrates. This experiment tested the hypotheses that using a RAFD during exercise would; decrease post-exercise peak inspiratory pressure (PPI) and peak expiratory (PPE) pressure, FVC and FEV1, and increase post-exercise flowrates. Using a repeated-measures, counter-balanced design, six healthy moderately aerobically-trained, men (mean ± SD; age 24.7 ± 1.7 years; peak oxygen utilization [VO2peak] 42.8 ± 5.3 ml kg-1 min-1) completed two 30 min exercise test sessions at a power output equal to 75% VO2peak. One session was performed not using (NORAFD), and one using a RAFD (Moldex 8000) fitted with organic vapor cartridges and combined dust and mist pre-filters (inspiratory resistance = 0.216 kPa, expiratory resistance = 0.094 kPa at 85.0 l min-1). All pulmonary function tests were performed immediately pre-(Pre) and 0 (Post-0), 5 (Post-5), and 15 (Post-15) min post-exercise. There was a significant (p

Mathematical models can be used to predict exercise performance, but the specific factors contributing to the fatigue component of these models are unknown. This study was designed to determine the contribution of nutrition and psychometric factors to the fatigue component of a performance prediction model for endurance running. It was hypothesized that there would be a positive correlation between both nutritional intake and psychometric factors, and the modeled fatigue. One experienced male marathon and ultra-marathon runner was monitored during 18-weeks of training, involving a weekly performance test (mean ± SD; distance = 10508 ± 113 m), nutritional diaries, and psychometric questionnaires (POMS and RESTQ-Sport). A dose-response based model incorporating two antagonistic components, fitness and fatigue, and training data, was used to calculate modeled performance, which was correlated against actual performance. The performance fit was low (r2 = 0.24, P = 0.05) when modelled for the total 122 day period, however the fit was increased when the model was divided into two separate training periods (days 1 - 66: r2 = 0.55, P = 0.02; days 66 - 122: r2 = 0.87, P = 0.002). There were significant (P

This study describes the physical activity across and within the lifetime of current ultra-endurance exercisers. Participants (n = 115, % female = 42, age range 21 to 74 years) completed a modified version of the Lifetime Physical Activity Questionnaire (LPAQ) to assess physical activity over six life periods (5-12, 13-18, 19-30, 31-45, 46-60 and 61-75 years). Participants then were categorised into five groups according to which of these life periods they demonstrated the largest absolute increase in ultra-endurance exercise (UEE included all running and cycling) compared to the previous life period. All groups demonstrated significant increases (p < .005) in UEE between their categorised life period of largest increase in UEE (IUEE) and the previous life period. Within groups, increases in average UEE MET-hours year-1 ranged from 144% to 402%. Lifetime exercise volumes varied considerably within groups (average lifetime MET-hrs year-1 IUEE13-18 = 3830 ± 2362; IUEE19-30 = 4358 ± 2832; IUEE31-45 = 2975 ± 1970; IUEE46-60 = 2839 ± 1721; IUEE61-75 = 3454 ± 1720) and within the entire sample (average lifetime MET-hrs year-1 = 3400 ± 2229 [range 375-12140]). This study is the first to describe the physical activity across and within the lifetime of ultra-endurance exercisers and reports that ultra-endurance exercisers exhibit significant increases in UEE within their lifetime.

Purpose: The playing formation of football teams influences how players interact with each other via passing. The aim of this study was to use network analysis to determine the passing characteristics of playing positions within a professional a professional football team across two consecutive competitive seasons, when playing two different formations. Methods: In season one (2016/2017) the team played 1-4-2-2-2 in 21 matches, and in season two (2017/2018) the team played 1-4-2-3-1 in 21 matches. Network analysis was applied to calculate the individual centrality metrics of indegree centrality (IDC), outdegree centrality (ODC), closeness centrality (CC), and betweenness centrality (BC) for the playing positions, using the Social Network Visualizer (SocNetV). The centrality metrics were compared across the playing formations and as a function of match outcome. Results: The forward positions in 1-4-2-2-2 had significantly (p Conclusions: The current study shows that subtle changes to playing formation elicit differences in the passing contributions of the players. The results suggest that coaches may adopt the playing formation 1-4-2-2-2 compared with 1-4-2-3-1 owing to the increased passing involvement from the forwards.

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.

Background Sprint interval training (SIT) can be as effective, or more effective, than continuous moderate intensity exercise (CMIE) for improving a primary risk factor for cardiometabolic disease, low cardiorespiratory fitness (CRF). However, there has been no direct comparison in inactive individuals, of the acute effects of a session of SIT with a work-matched session of CMIE on local oxygen utilisation, which is a primary stimulus for increasing CRF. Furthermore, post-exercise blood pressure (BP) and enjoyment, if symptomatic and low, respectively, have implications for safety and adherence to exercise and have not been compared between these specific conditions. It was hypothesised that in young inactive men, local oxygen utilisation would be higher, while post-exercise BP and enjoyment would be lower for SIT, when compared to CMIE. Methods A total of 11 inactive men (mean ± SD; age 23 ± 4 years) completed a maximal ramp-incremental exercise test followed by two experiment conditions: (1) SIT and (2) work-matched CMIE on a cycle ergometer on separate days. Deoxygenated haemoglobin (∆HHb) in the pre-frontal cortex (FH), gastrocnemius (GN), left vastus lateralis (LVL) and the right vastus lateralis (RVL) muscles, systemic oxygen utilisation (VO2), systolic (SBP) and diastolic (DBP) blood pressure and physical activity enjoyment scale (PACES) were measured during the experiment conditions. Results During SIT, compared to CMIE, ∆HHb in FH (p = 0.016) and GN (p = 0.001) was higher, while PACES (p = 0.032) and DBP (p = 0.043) were lower. No differences in SBP and ∆HHb in LVL and RVL were found between conditions. Conclusions In young inactive men, higher levels of physiological stress occurred during SIT, which potentially contributed to lower levels of post-exercise DBP and enjoyment, when compared to CMIE.

Background: Systems thinking, a fundamental approach for understanding complexity, is beginning to gain traction in sports science. Systems archetypes (SAs) describe common recurring patterns of system behaviors and have been used extensively in other domains to explain the system wide influences on behavior. SAs look at the deeper levels of systemic structure by identifying what creates system behaviors, which supports the development of interventions to identify and resolve problem sources. Methods: Four commonly used SAs were used to explain the dynamics underpinning recurring issues for coaching in football: (1) Fixes that fail, (2) Shifting the burden, (3) Drifting goals, and (4) Success to the successful. The SAs models were built, refined and validated by seven subject matter experts (SMEs) including experienced football researchers, systems thinking experts, an international football coach, a skill acquisition specialist, and an experienced exercise scientist. Results: The findings show that the SAs fit well in the football coaching context, providing further evidence that a complex system thinking approach is required when considering football performance and its optimization. The developed SAs identify the factors that play a role in recurring issues in football coaching and highlight the systemic structures that contribute to the issues. The developed SAs identify the appropriate leverage points in the system where sustainable change can be made to improve coaching practice and subsequent performance of players. Discussion: A common theme emerging across the analyses was that systemic problems often arise in football when quick fixes are attempted. Whereas, improvements to system behavior usually require a delay after the implementation of the appropriate corrective action. The SAs developed in the current study also provide practical templates of common problems in football that can be used to prompt discussions around how to avoid ineffective interventions and instead make sustainable improvements across multiple aspects of football performance.

BACKGROUND: There is currently no information on the lifetime diet of ultra-endurance exercisers. This study describes changes in diet across the lifetime of current ultra-endurance exercisers and the relationship between diet and physical activity (specifically ultra-endurance exercise [UEE]). METHODS: Lifetime physical activity and diet were assessed in current ultra-endurance exercisers (n=120; ages 21-74 years) over six life periods (5-12, 13-18, 19-30, 31-45, 46-60, 61-75 years). Using the life period having the largest absolute increase in UEE (IUEE), diet was assessed according to food category scores and dietary patterns. Changes in lifetime diet were described by comparing food category scores between adjacent life periods. Differences in food category scores were investigated between the life period for each IUEE group and the preceding life period and associations between dietary patterns and UEE were investigated within each IUEE group. Relationships between lifetime diet and UEE were investigated by examining associations between lifetime food category scores and lifetime UEE. RESULTS: The participant group had significant increases in all food category scores from 13-18 to 19-30 years and significant decreases in all food category scores from 19-30 to 31-45 years. UEE correlated negatively with the Western style dietary pattern in the IUEE19- 30 group and positively with the fruit and vegetable dietary pattern in the IUEE31-45 group. There was a positive correlation between lifetime UEE and lifetime vegetables and fruit category scores. CONCLUSIONS: The ultra-endurance exercisers in this study exhibited changes in diet similar to general populations, which appear to reflect typical nutritional requirements across the lifespan.

Buzza, G, Lovell, GP, Askew, CD, and Solomon, C. The effect of short- and long-term aerobic training years on systemic O2 utilization, and muscle and prefrontal cortex tissue oxygen extraction in young women. J Strength Cond Res 33(8): 2128-2137, 2019-This study aimed to determine if systemic O2 utilization (VO2) and tissue oxygen extraction (deoxyhemoglobin [HHb]) in the vastus lateralis (VL), gastrocnemius (GAST), and prefrontal cortex were different during exercise between short-term trained (STT, 6-24 months) and long-term trained (LTT, >5 years) young women while controlling for current training load. Thirteen STT and 13 LTT participants completed ramp incremental (RI) and square-wave constant load (SWCL) tests on a cycle ergometer. In LTT compared with STT: (a) VO2 was higher during the RI (p = 0.024) and SWCL (p = 0.001) tests; (b) HHb in the VL (p = 0.044) and GAST (p = 0.027) was higher in the RI test; and (c) there were significant group × intensity interactions for VO2 in the SWCL test. The additional years of aerobic training in LTT compared with STT (LTT 7.1 ± 1.9 vs. STT 1.5 ± 0.4 years) resulted in higher VO2 and HHb in the VL and GAST. These results indicate that in young women, independent of current training load, systemic VO2 and peripheral muscle O2 extraction during exercise continues to increase beyond 24 months of aerobic training.

Background:An increase in bicycle commuting participation may improve public health and traffic congestion in cities. Information on air pollution exposure (such as perception, symptoms, and risk management) contributes to the responsible promotion of bicycle commuting participation.Methods:To determine perceptions, symptoms, and willingness for specific exposure risk management strategies of exposure to air pollution, a questionnaire-based cross-sectional investigation was conducted with adult bicycle commuters (n = 153; age = 41 ± 11 years; 28% female).Results:Frequency of acute respiratory signs and symptoms were positively associated with in-commute and postcommute compared with precommute time periods (P < .05); there was greater positive association with respiratory disorder compared with healthy, and female compared with male, participants. The perception (but not signs or symptoms) of in-commute exposure to air pollution was positively associated with the estimated level of in-commute proximity to motorized traffic. The majority of participants indicated a willingness (which varied with health status and gender) to adopt risk management strategies (with desired features) if shown to be appropriate and effective.Conclusions:While acute signs and symptoms of air pollution exposure are indicated with bicycle commuting, and more so in susceptible individuals, there is willingness to manage exposure risk by adopting effective strategies with desired features.

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.

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.

PURPOSE: The dynamics of speed selection as a function of distance, or pacing, are used in recreational, competitive, and scientific research situations as an indirect measure of the psycho-physiological status of an individual. The purpose of this study was to determine pacing on level, uphill and downhill sections of participants in a long (>80 km) ultramarathon performed on trails in hilly terrain. METHODS: Fifteen ultramarathon runners competed in a 173 km event (five finished at 103 km) carrying a Global-Positioning System (GPS) device. Using the GPS data, we determined the speed, relative to average total speed, in level (LEV), uphill (UH) and downhill (DH) gradient categories as a function of total distance, as well as the correlation between overall performance and speed variability, speed loss, and total time stopped. RESULTS: There were no significant differences in normality, variances or means in the relative speed in 173-km and 103-km participants. Relative speed decreased in LEV, UH and DH. The main component of speed loss occurred between 5% and 50% of the event distance in LEV, and between 5% and 95% in UH and DH. There were no significant correlations between overall performance and speed loss, the variability of speed, or total time stopped. CONCLUSIONS: Positive pacing was observed at all gradients, with the main component of speed loss occurring earlier (mixed pacing) in LEV compared to UH and DH. A speed reserve (increased speed in the last section) was observed in LEV and UH. The decrease in speed and variability of speed were more important in LEV and DH than in UH. The absence of a significant correlation between overall performance and descriptors of pacing is novel and indicates that pacing in ultramarathons in trails and hilly terrain differs to other types of running events.

Frequent exposure to ultrafine particles (UFP) is associated with detrimental effects on cardiopulmonary function and health. UFP dose and therefore the associated health risk are a factor of exposure frequency, duration, and magnitude of (therefore also proximity to) a UFP emission source. Bicycle commuters using on-road routes during peak traffic times are sharing a microenvironment with high levels of motorised traffic, a major UFP emission source. Inhaled particle counts were measured along popular pre-identified bicycle commute route alterations of low (LOW) and high (HIGH) motorised traffic to the same inner-city destination at peak commute traffic times. During commute, real-time particle number concentration (PNC; mostly in the UFP range) and particle diameter (PD), heart and respiratory rate, geographical location, and meteorological variables were measured. To determine inhaled particle counts, ventilation rate was calculated from heart-rate-ventilation associations, produced from periodic exercise testing. Total mean PNC of LOW (compared to HIGH) was reduced (1.56 x e4 ± 0.38 x e4 versus 3.06 x e4 ± 0.53 x e4 ppcc; p = 0.012). Total estimated ventilation rate did not vary significantly between LOW and HIGH (43 ± 5 versus 46 ± 9 L•min; p = 0.136); however, due to total mean PNC, accumulated inhaled particle counts were 48% lower in LOW, compared to HIGH (7.6 x e8 ± 1.5 x e8 versus 14.6 x e8 ± 1.8 x e8; p = 0.003). For bicycle commuting at peak morning commute times, inhaled particle counts and therefore cardiopulmonary health risk may be substantially reduced by decreasing exposure to motorised traffic, which should be considered by both bicycle commuters and urban planners.

BackgroundHigh-intensity interval training (HIIT) has been proposed as a time-efficient exercise format to improve exercise adherence, thereby targeting the chronic disease burden associated with sedentary behaviour. Exercise mode (cycling, running), if self-selected, will likely affect the physiological and enjoyment responses to HIIT in sedentary individuals. Differences in physiological and enjoyment responses, associated with the mode of exercise, could potentially influence the uptake and continued adherence to HIIT. It was hypothesised that in young sedentary men, local and systemic oxygen utilisation and enjoyment would be higher during a session of running HIIT, compared to a session of cycling HIIT.MethodsA total of 12 sedentary men (mean ± SD; age 24 ± 3 years) completed three exercise sessions: a maximal incremental exercise test on a treadmill (MAX) followed by two experiment conditions, (1) free-paced cycling HIIT on a bicycle ergometer (HIITCYC) and (2) constant-paced running HIIT on a treadmill ergometer (HIITRUN). Deoxygenated haemoglobin (HHb) in the gastrocnemius (GN), the left vastus lateralis (LVL) and the right vastus lateralis (RVL) muscles, oxygen consumption (VO2), heart rate (HR), ratings of perceived exertion (RPE) and physical activity enjoyment (PACES) were measured during HIITCYC and HIITRUN.ResultsThere was a higher HHb in the LVL (p= 0.001) and RVL (p= 0.002) sites and a higher VO2(p= 0.017) and HR (p< 0.001) during HIITCYC, compared to HIITRUN. RPE was higher (p< 0.001) and PACES lower (p= 0.032) during HIITCYC compared to HIITRUN.DiscussionIn sedentary individuals, free-paced cycling HIIT produces higher levels of physiological stress when compared to constant-paced running HIIT. Participants perceived running HIIT to be more enjoyable than cycling HIIT. These findings have implications for selection of mode of HIIT for physical stress, exercise enjoyment and compliance.

Objective: This experiment was designed to test if controlled exposure to particles and ozone would result in decreased heart rate variability (HRV). Methods: Five asthmatic adults were exposed for 4 hours to; filtered-air, carbon and ammonium nitrate particles, and particles and ozone. Twenty-minute electrocardiograms were obtained before and after each exposure. Results: Standard deviation of all normal-to-normal beat intervals (SDNN) decreased significantly across particles and ozone exposure compared with across filtered-air exposure (P = 0.01). Changes in SDNN-I (P = 0.04) and normalized low and high frequency (P = 0.02) were also seen across particles and ozone exposure; although these changes may best be characterized as trends given the small sample size. No significant changes in HRV were seen across the filtered-air or particles-only exposures. Conclusions: The results of this study suggest that combined particle and ozone exposure may decrease HRV in asthmatics. Further investigation is needed to confirm this finding.

Long-duration exercise has been linked with the psychological model of flow. It is expected that the flow experience is characterized by specific changes in cortical activity, especially a transient hypofrontality, which has recently been connected with an increase in cognitive performance post-exercise. Nevertheless, data on neuro-affective and neuro-cognitive effects during prolonged exercise are rare. The cognitive performance, mental state, flow experience, and brain cortical activity of 11 ultramarathon runners (6 female, 5 male) were assessed before, several times during, and after a 6-h run. A decrease in cortical activity (beta activity) was measured in the frontal cortex, whereas no changes were measured for global beta, frontal or global alpha activity. Perceived physical relaxation and flow state increased significantly after 1 h of running but decreased during the following 5 h. Perceived physical state and motivational state remained stable during the first hour of running but then decreased significantly. Cognitive performance as well as the underlying neurophysiological events (recorded as event-related potentials) remained stable across the 6-h run. Despite the fact that women reported significant higher levels of flow, no further gender effects were noticeable. Supporting the theory of a transient hypofrontality, a clear decrease in frontal cortex activity was noticeable. Interestingly, this had no effect on cognitive performance. The fact that self-reported flow experience only increased during the first hour of running before decreasing, leads us to assume that changes in cortical activity, and the experience of flow may not be linked as previously supposed.

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.

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.

Single short-term exposures to ozone are known to cause acute changes in pulmonary function and neutrophilic airway inflammation. The respiratory health effects of repeated exposures are not as well studied. Pulmonary function decrements are known to attenuate, but it is less clear how injury and inflammation are affected. Using sputum induction (SI) to sample respiratory tract lining fluid after single- and multiday exposures, we designed a study to test the hypothesis that neutrophils would increase after multiday exposure compared with single-day exposure. In a randomized, crossover design, 15 normal healthy subjects were exposed to O3 (0.2 ppm) under two conditions: for 4 hr for 1 day (1D) and for 4 hr for 4 consecutive days (4D). Pulmonary function testing was performed immediately before and after each 4-hr exposure. The SI was performed 18 hr after the end of the 1D and 4D conditions. The symptom and pulmonary function data followed a pattern seen in other multiday O3 exposure studies, with the greatest changes occurring on the second day. In contrast to previous studies using bronchoalveolar lavage, however, there was a significant increase in the percentage of neutrophils and a significant decrease in the percentage of macrophages after the 4D condition compared with the 1D condition. Given that SI likely samples proximal airways better than distal lung, these results add to the body of evidence that differential airway compartmental responses to O3 occur in humans and other species.

Rationale: Repeated, short-term exposures to ozone (O3) lead to attenuation of the acute lung function and airway inflammatory responses seen after a single exposure in healthy subjects, but it is unclear whether these acute responses also attenuate in subjects with asthma. Objective: To address this question by exposing 14 subjects with asthma to 0.2 ppm O3 for either 4 hours on a single day or 4 hours on 4 consecutive days (multiday [MD]). At least 3 weeks later, subjects underwent the alternate exposure. Methods: Spirometry was performed immediately pre- and postexposure and bronchoalveolar lavage (BAL) was obtained 18 hours after each exposure. Main Results: The decrease in FEV1 was greatest across Day 2 of the MD (MD2) exposure and then gradually declined on successive days of the MD exposure (mean ± SD decrease in FEV1 of 25.4 ± 18.0% across MD2 compared with 4.2 ± 6.5% across MD4). Respiratory symptoms followed a similar pattern to that of FEV1. Although the concentration of neutrophils in BAL after the MD4 exposure was not significantly different from that after the single-day exposure (1.7 ± 1.3 × 104 cells/ml vs. 1.2 ± 0.8 × 104 cells/ml, p = 0.20), the concentration of alveolar macrophages did significantly increase in BAL after the MD exposure (19.9 ± 9.7 × 104 cells/ml after MD4 vs. 12.1 ± 6.4 × 104 cells/ml after the single day). Conclusions: Alveolar macrophages are recruited to the airways of subjects with asthma with repeated short-term exposures to O3, suggesting a possible role for these cells in the chronic response to oxidant-induced injury.

Carbonic anhydrase (CA) is physiologically important in the reversible hydration reaction of CO(2); it is expressed in a number of isoforms (CA I-XIV) with varying degrees of enzymatic activity. In nasal chemesthesis, CA inhibition decreases the electrophysiologic response to CO(2), a common irritant test compound. CA enzymatic activity has been demonstrated in the human nasal mucosa using enzyme histochemical methods, but no systematic study of nasal mucosal CA isoenzyme gene expression has been published. We examined CA gene expression in superficial nasal mucosal scrapings from 15 subjects (6 females; 6 allergic rhinitics; age range, 21-56 years). Both non-quantitative and quantitative reverse transcription polymerase chain reaction (RT-PCR) were performed using primers for each gene coding for the 11 catalytically active CA isoenzymes and the housekeeping gene GADPH. Amplification products of GADPH and 10 of the 11 CA genes were detected in the specimens (CA VA was not detected). Relative expression of the CA genes was quantified using real-time PCR. Averaged across subjects, the relative abundance of the CA isoenzyme transcripts is as follows: CA XII > CA II > CA VB > CA IV > CA IX > CA III > CA XIV > CA I > CA VI > CA VII. Limited qualitative validation of gene expression was obtained by immunohistochemistry for CA I, CA II and CA IV. We also observed inter-individual variability in the expression of CA isoenzymes in human nasal mucosa, potentially contributing to differences in nasal chemosensitivity to CO(2) between individuals

A unique burner system was designed for the purposes of exposing human subjects to rice straw smoke under highly controlled conditions. The system burns individual straws and has produced particle concentrations up to 900 w g m m 3 in a temperature- and humidity-controlled exposure chamber. Burner operation is fully automatic and programmable. Ignition is by radiant heating in a manner similar to the field. Particle concentration is controlled by the firing interval between straws and by the ratio of burner outlet flow mixing with the main purified air supplied to the exposure chamber. Steady-state particle concentrations are achieved within 5 min from start. Repeatability of particle concentration is excellent at the two exposure levels used, 200 and 500 w g m m 3 . Measurements of particle size distributions suggest that approximately 80% of mass is in the size fraction below 1 w m. Although particle concentrations are controlled at target levels with good precision, emission factors are higher than ach...

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} }{}$\dot {\mathrm{V }}{\mathrm{O}}_{2}$\end{document}V ˙O2) and the energy cost of running (Cr) during prolonged running are not completely understood, and could be linked with alterations in muscle and cerebral tissue oxygenation. Methods Eight trained ultramarathon runners (three women; mean ± SD; age 37 ± 7 yr; maximum \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$\dot {\mathrm{V }}{\mathrm{O}}_{2}$\end{document}V ˙O2 60 ± 15 mL min−1 kg−1) completed a 6 hr treadmill run (6TR), which consisted of four modules, including periods of moderate (3 min at 10 km h−1, 10-CR) and heavy exercise intensities (6 min at 70% of maximum \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$\dot {\mathrm{V }}{\mathrm{O}}_{2}$\end{document}V ˙O2, HILL), separated by three, 100 min periods of self-paced running (SP). We measured \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$\dot {\mathrm{V }}{\mathrm{O}}_{2}$\end{document}V ˙O2, minute ventilation (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}${\dot {\mathrm{V }}}_{\mathrm{E}}$\end{document}V ˙E), ventilatory efficiency (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}${\dot {\mathrm{V }}}_{\mathrm{E}}:\dot {\mathrm{V }}{\mathrm{O}}_{2}$\end{document}V ˙E:V ˙O2), respiratory exchange ratio (RER), Cr, muscle and cerebral tissue saturation index (TSI) during the modules, and heart rate (HR) and perceived exertion (RPE) during the modules and SP. Results Participants ran 58.3 ± 10.5 km during 6TR. Speed decreased and HR and RPE increased during SP. Across the modules, HR and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$\dot {\mathrm{V }}{\mathrm{O}}_{2}$\end{document}V ˙O2 increased (10-CR), and RER decreased (10-CR and HILL). There were no significant changes in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}${\dot {\mathrm{V }}}_{\mathrm{E}}$\end{document}V ˙E, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}${\dot {\mathrm{V }}}_{\mathrm{E}}:\dot {\mathrm{V }}{\mathrm{O}}_{2}$\end{document}V ˙E:V ˙O2, Cr, TSI and RPE across the modules. Conclusions In the context of positive pacing (decreasing speed), increased cardiac drift and perceived exertion over the 6TR, we observed increased RER and increased HR at moderate and heavy exercise intensity, increased \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$\dot {\mathrm{V }}{\mathrm{O}}_{2}$\end{document}V ˙O2 at moderate intensity, and no effect of exercise duration on ventilatory efficiency, energy cost of running and tissue oxygenation.

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.

Interleukin (IL)-13, a cytokine released by T lymphocytes during immediate hypersensitivity responses, is a central mediator of asthma. Because IL-13 induces phenotypic features of asthma in mice deficient in T and B lymphocytes, it is likely that this cytokine contributes to the development of asthma by acting directly on resident airway cells. To analyze the global effects of IL-13 on gene expression in airway cells that could contribute to the phenotypic features of asthma, we used Genechip HuGene FL arrays (Affymetrix, Santa Clara, CA) that contain probes for approximately 6,500 human genes. Despite activating a common signaling pathway, IL-13 induced dramatically different patterns of gene expression in primary cultures of airway epithelial cells, airway smooth muscle cells, and lung fibroblasts, with little overlap among cell types. The most prominent effects of IL-13 were on airway smooth muscle, but several genes induced in airway epithelial cells and fibroblasts are also candidates that may contribute to phenotypic features of asthma. These results suggest that the in vivo response to IL-13 in the airways likely results from a combination of distinct effects on each of several resident airway cell types.

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.

Background: More than two-fifths of the world’s population uses solid fuels, mostly biomass, for cooking. The resulting biomass smoke exposure is a major cause of chronic obstructive pulmonary disease (COPD) among women in developing countries. Objective: To assess whether lower woodsmoke exposure from use of a stove with a chimney, compared to open fires, is associated with lower markers of airway inflammation in young women. Design: We carried out a cross-sectional analysis on a sub-cohort of participants enrolled in a randomized controlled trial in rural Guatemala, RESPIRE. Participants: We recruited 45 indigenous women at the end of the 18-month trial; 19 women who had been using the chimney stove for 18–24 months and 26 women still using open fires. Measurements: We obtained spirometry and induced sputum for cell counts, gene expression of IL-8, TNF-α, MMP-9 and 12, and protein concentrations of IL-8, myeloperoxidase and fibronectin. Exhaled carbon monoxide (CO) and 48-hr personal CO tubes were measured to assess smoke exposure. Results: MMP-9 gene expression was significantly lower in women using chimney stoves. Higher exhaled CO concentrations were significantly associated with higher gene expression of IL-8, TNF-α, and MMP-9. Higher 48-hr personal CO concentrations were associated with higher gene expression of IL-8, TNF- α, MMP-9 and MMP-12; reaching statistical significance for MMP-9 and MMP-12. Conclusions: Compared to using an open wood fire for cooking, use of a chimney stove was associated with lower gene expression of MMP-9, a potential mediator of airway remodeling. Among all participants, indoor biomass smoke exposure was associated with higher gene expression of multiple mediators of airway inflammation and remodeling; these mechanisms may explain some of the observed association between prolonged biomass smoke exposure and COPD.

To the Editor: We read with great interest the report of Schins et al. 1 on their controlled human-exposure study of chlorine inhalation. The air pollutant studied, gaseous chlorine, is one of substantial relevance in terms of total industrial usage and involvement in emergency release scenarios. The authors referred to “…a paucity of human data on the effect …

Objective: We sought to determine whether nitrogen dioxide (NO 2 ) can enhance airway inflammation after allergen challenge in asthmatic subjects. Methods: Fifteen house-dust-mite (HDM)-sensitive asthmatic subjects were exposed for 3 hours to filtered air or 0.4 ppm NO 2 , followed by inhalational challenge with HDM allergen. Markers of inflammation were measured in sputum at 6 hours and 26 hours after allergen challenge. Results: After exposure to NO 2 , eosinophil concentration decreased significantly in the 6-hour postallergen sputum. No significant NO 2 -Telated difference was observed for other variables. Conclusions: Our results suggest that, in most asthmatic individuals, multihour exposure to a high ambient concentration of NO 2 does not enhance the inflammatory response to subsequent inhaled allergen as assessed by cell distribution in induced sputum. Because the decrease in airway eosinophils has been reported in previous animal studies, future research should be directed toward the mechanism of this effect.