Fatigue Induced Changes in Muscle Strength and Gait Following Two Different Intensity, Energy Expenditure Matched Runs

Purpose: To investigate changes in hip and knee strength, kinematics, and running variability following two energy expenditure matched training runs; a medium intensity continuous run (MICR) and a high intensity interval training session (HIIT). Methods: Twenty (10F, 10M) healthy master class runners were recruited. Each participant completed the HIIT consisting of six repetitions of 800 meters with a 1:1 work: rest ratio. The MICR duration was set to match energy expenditure of the HIIT session. Hip and knee muscular strength were examined pre and post both HIIT and MICR. Kinematics and running variability for hip and knee, along with spatiotemporal parameters were assessed at start and end of each run-type. Changes in variables were examined using both 2 x 2 ANOVAs with repeated measures and on an individual level when the change in a variable exceeded the minimum detectable change (MDC). Results: All strength measures exhibited significant reductions at the hip and knee (P < .05) with time for both run-types; 12% following HIIT, 10.6% post MICR. Hip frontal plane kinematics increased post run for both maximum angle (P < 0.001) and range of motion (P = 0.003). Runners exhibited increased running variability for nearly all variables, with the HIIT having a greater effect. Individual assessment revealed that not all runners were effected post run and that following HIIT more runners had reduced muscular strength, altered kinematics and increased running variability. Conclusion: Runners exhibited fatigue induced changes following typical training runs, which could potentially increase risk of injury development. Group and individual assessment revealed different findings where the use of MDC is recommended over that of P values

Development of a simulated round of golf

Purpose The aim of this study was to develop a laboratory-based treadmill simulation of the on-course physiological demands of an 18-hole round of golf and to identify the underlying physiological responses. Methods Eight amateur golfers completed a round of golf during which heart rate (HR), steps taken, and global positioning system (GPS) data were assessed. The GPS data were used to create a simulated discontinuous round on a treadmill. Steps taken and HR were recorded during the simulated round. Results During the on-course round, players covered a mean (±SD) of 8,251 ± 450 m, taking 12,766 ± 1,530 steps. The mean exercise intensity during the on-course round was 31.4 ± 9.3% of age-predicted heart rate reserve (%HRR) or 55.6 ± 4.4% of age-predicted maximum HR (%HRmax). There were no significant differences between the simulated round and the on-course round for %HRR (P = .537) or %HR max (P = .561) over the entire round or for each individual hole. Furthermore, there were no significant differences between the two rounds for steps taken. Typical error values for steps taken, HR, %HRmax, and %HRR were 1,083 steps, ±7.6 b·min?1, ±4.5%, and ±8.1%, respectively. Conclusion Overall, the simulated round of golf successfully recreated the demands of an on-course round. This simulated round could be used as a research tool to assess the extent of fatigue during a round of golf or the impact of various interventions on golfers

Use of loaded conditioning activities to potentiate middle- and long-distance performance: a narrative review and practical applications

The warm-up is an integral component of a middle- and long-distance athlete’s pre-performance routine. The use of a loaded conditioning activity (LCA), which elicits a post-activation potentiation (PAP) response to acutely enhance explosive power performance, is well-researched. A similar approach incorporated into the warm-up of a middle- or long-distance athlete potentially provides a novel strategy to augment performance. Mechanisms that underpin a PAP response, relating to acute adjustments within the neuromuscular system, should theoretically improve middle- and long-distance performance via improvements in sub-maximal force-generating ability. Attempts to enhance middle- and long-distance related outcomes using a LCA have been used in several recent studies. Results suggest benefits to performance may exist in well-trained middle- and long-distance athletes by including high-intensity resistance training (1-5 repetition maximum) or adding load to the sport skill itself during the latter part of warm-ups. Early stages of performance appear to benefit most, and it is likely that recovery (5-10 min) also plays an important role following a LCA. Future research should consider how priming activity, designed to enhance the V[Combining Dot Above]O2 kinetic response, and a LCA may interact to affect performance, and how different LCA’s might benefit various modes and durations of middle- and long-distance exercise

Effects of Strength Training on the Physiological Determinants of Middle- and Long-Distance Running Performance: A Systematic Review

Background Middle- and long-distance running performance is constrained by several important aerobic and anaerobic parameters. The efficacy of strength training (ST) for distance runners has received considerable attention in the literature. However, to date, the results of these studies have not been fully synthesized in a review on the topic. Objectives This systematic review aimed to provide a comprehensive critical commentary on the current literature that has examined the effects of ST modalities on the physiological determinants and performance of middle- and long-distance runners, and offer recommendations for best practice. Methods Electronic databases were searched using a variety of key words relating to ST exercise and distance running. This search was supplemented with citation tracking. To be eligible for inclusion, a study was required to meet the following criteria: participants were middle- or long-distance runners with ≥ 6 months experience, a ST intervention (heavy resistance training, explosive resistance training, or plyometric training) lasting ≥ 4 weeks was applied, a running only control group was used, data on one or more physiological variables was reported. Two independent assessors deemed that 24 studies fully met the criteria for inclusion. Methodological rigor was assessed for each study using the PEDro scale. Results PEDro scores revealed internal validity of 4, 5, or 6 for the studies reviewed. Running economy (RE) was measured in 20 of the studies and generally showed improvements (2–8%) compared to a control group, although this was not always the case. Time trial (TT) performance (1.5–10 km) and anaerobic speed qualities also tended to improve following ST. Other parameters [maximal oxygen uptake ( V˙O2max), velocity at V˙O2max, blood lactate, body composition] were typically unaffected by ST. Conclusion Whilst there was good evidence that ST improves RE, TT, and sprint performance, this was not a consistent finding across all works that were reviewed. Several important methodological differences and limitations are highlighted, which may explain the discrepancies in findings and should be considered in future investigations in this area. Importantly for the distance runner, measures relating to body composition are not negatively impacted by a ST intervention. The addition of two to three ST sessions per week, which include a variety of ST modalities are likely to provide benefits to the performance of middle- and long-distance runners

Dose-Response Relationship between Training Load and Changes in Aerobic Fitness in Professional Youth Soccer Players

Purpose: The aim of this study was to compare the dose-response relationship between, traditional arbitrary speed thresholds versus an individualised approach, with changes in aerobic fitness in professional youth soccer players. Methods: Fourteen youth soccer players, completed a 1500 metre time trial to estimate maximal aerobic speed (km.h-1, (MAS)) at the start and the end of a six week period. Training load was monitored on a daily basis during this study. External load measures were; total distance covered (TD), total acceleration and deceleration distance > 2m.s-2 (A/D Load). Arbitrary high speed running measures were; metres covered and time spent > 17 km.h-1 (m>HSD, t>HSD) and 21 km.h-1 (m>VHSD, t>VHSD). Individualised high speed running measures were; metres covered and time spent > MAS km.h-1 (m>MAS, t>MAS) and 30% anaerobic speed reserve (m>30ASR, t>30ASR). In addition, internal load measures were also collected; heart rate exertion (HRE) and rating of perceived exertion (RPE). Linear regression analysis was used to establish the dose-response relationship between mean weekly training load and changes in aerobic fitness. Results: Substantial very large associations were found between t>MAS and changes in aerobic fitness (R2 = 0.59). Substantial large associations were found for t>30ASR (R2 = 0.38) and m>MAS (R2 = 0.25). Unsubstantial associations were found for all other variables. Conclusion: An individualised approach to monitoring training load, in particular t>MAS, may be a more appropriate method than using traditional arbitrary speed thresholds when monitoring the dose-response relationship between training load and changes in aerobic fitness

Planning for optimal performance – what happens before the taper?

This study analysed contemporary performance data of middle distance athletes to determine a) the number of competitive performances prior to the season's fastest performance and b) the time frame between their first and fastest competitive performances of that season. Using a publicly available database, data on the number of races and days between athletes first and fastest races were extracted. The analysis utilised 4,800 observations from 1,166 individual athletes for the period 2006 to 2017. Male 800 m athletes achieved their fastest performance in 8 races (IQR=4-12) distributed over 55 days (IQR=29-87). Female 800 m athletes also required 8 races (IQR=5-12), distributed over 63 days (IQR=34-91). In the 1500 m event, male athletes, required 6 races (IQR=3-9) over 48 days (IQR=25-76), while female athletes, required 7 races (IQR=4-10) over 56 days (IQR=28-84). For both sexes, 1500 m athletes raced less, and over a shorter period than 800 m athletes before reaching their fastest performance. Female athletes, had a longer time frame and number of races than male athletes. This study provides an evidence-based indicator of when a middle distance runner’s fastest performance is likely to occur, providing benchmarks that could act as a guide for coaches when designing competition programmes, prior to any tapering process

Incremental Semantic Evaluation for Interactive Systems: Inertia, Pre-emption, and Relations

Although schemes for incremental semantic evaluation have been explored and refined for more than two decades, the demands of user interaction continue to outstrip the capabilities of these schemes. The feedback produced by a semantic evaluator must support the user's programming activities: it must be structured in a way that provides the user with meaningful insight into the program (directly, or via other tools in the environment) and it must be timely. In this paper we extend an incremental attribute evaluation scheme with three techniques to better meet these demands within the context of a modeless editing system with a flexible tool integration paradigm. Efficient evaluation in the presence of syntax errors (which arise often under modeless editing) is supported by giving semantic attributes inertia: a tendency to not change unless necessary. Pre-emptive evaluation helps to reduce the delays associated with a sequence of edits, allowing an evaluator to "keep pace" with the user. Relations provide a general means to capture semantic structure (for the user, other tools, and as attributes within an evaluation) and are treated efficiently using a form of differential propagation. The combination of these three techniques meets the demands of user interaction; leaving out any one does not

Examining the Relationships Between Coaching Practice and Athlete “Outcomes”: A Systematic Review and Critical Realist Critique

A widely accepted role of the sport coach is to elicit positive athlete ‘outcomes’ (e.g., enhanced performance, wellbeing, confidence etc.). However, evidence concerning the relationships between coaching practice and athlete outcomes is fragmented leaving researchers and practitioners little clarity to inform their work. Through a systematic search protocol and critique conducted through the lens of critical realism, this paper provides an overview of 208 English language peer-reviewed studies investigating relationships between coaching practice and athlete outcomes, and how current approaches may facilitate or hinder our understanding. Findings indicate research has predominantly utilised quantitative, cross-sectional or correlational approaches, with limited explicit consideration of paradigmatic influences. Discourse is dominated by psychological theorising (e.g., motivation), with studies generally employing single-method research designs and engaging a singular perspective (e.g., the athlete). Thus, we have a broad understanding of some coaching practice variables that may influence athlete outcomes (i.e., the what), but lack more interpretive and causal explanations of how and why practice is influential, accounting for the inherently complex and multi-faceted nature of the coaching process. Future research directions are proposed, which it is hoped will extend our understanding of the often intricate, heterogeneous influence of coaching practice, supporting coach educators and coaches

Efficacy of depth jumps to elicit a post-activation performance enhancement in junior endurance runners

Objectives: To determine the effect of performing depth jumps (DJ) pre-exercise on running economy (RE) and time to exhaustion (TTE) at the speed associated with maximal oxygen uptake (sV̇O2max) in a group of high-performing junior middle-distance runners.Design: Randomized crossover study.Methods: Seventeen national- and international-standard male distance runners (17.6 ± 1.2 years, 63.4 ± 6.3 kg, 1.76 ± 0.06 m, 70.7 ± 5.2 ml.kg-1.min-1) completed two trials. Following a 5 min warm-up at 60% V̇O2max, participants performed a 5 min run at 20%Δ below oxygen uptake corresponding with lactate turn-point to determine pre-intervention RE. Participants then completed either six DJ from a box equivalent to their best counter-movement jump (CMJ) or a control condition (C) involving body weight quarter squats. After a 10 min passive recovery, another 5 min sub-maximal run was performed followed by a run to exhaustion at sV̇O2max.Results: Compared to the C trial, DJ produced moderate improvements (-3.7%, 95% confidence interval for effect size: 0.25-1.09) in RE, which within the context of minimal detectable change is considered possibly beneficial. Differences in TTE and other physiological variables were most likely trivial (ES: <0.2). Individual responses were small, however a partial correlation revealed a moderate relationship (r=-0.55, p=0.028) between change in RE and CMJ height.Conclusions: The inclusion of a set of six DJ in the warm-up routine of a well-trained young male middle-distance runner is likely to provide a moderate improvement in RE

Translating pumping test data into groundwater model parameters: a workflow to reveal aquifer heterogeneities and implications in regional model parameterization

Groundwater modelers frequently grapple with the challenge of integrating aquifer test interpretations into parameters used by regional models. This task is complicated by issues of upscaling, data assimilation, and the need to assign prior probability distributions to numerical model parameters in order to support model predictive uncertainty analysis. To address this, we introduce a new framework that bridges the significant scale differences between aquifer tests and regional models. This framework also accounts for loss of original datasets and the heterogeneous nature of geological media in which aquifer testing often takes place. Using a fine numerical grid, the aquifer test is reproduced in a way that allows stochastic representation of site hydraulic properties at an arbitrary level of complexity. Data space inversion is then used to endow regional model cells with upscaled, aquifer-test-constrained realizations of numerical model properties. An example application demonstrates that assimilation of historical pumping test interpretations in this manner can be done relatively quickly. Furthermore, the assimilation process has the potential to significantly influence the posterior means of decision-pertinent model predictions. However, for the examples that we discuss, posterior predictive uncertainties do not undergo significant reduction. These results highlight the need for further research