676 research outputs found
Does ketone ester supplementation really blunt overreaching symptoms during endurance training overload?
No full textIn a recent paper published in the Journal of Physiology, Poffe´ et al.(2019) concluded that ‘ketone ester intake is a potent nutritional strategy to prevent the development of non-functional overreaching’. I argue that such a conclusion cannot be proposed from the data presented in their paper.Full Tex
Episode 1: Friction and Flow – Comparing and Contrasting Clausewitz’ and Sun Tzu’s Theories of War
No full textGuests Vanya Bellinger and Andrew Dex Wilson join host Brendan Neagle to compare and contrast the foundational theorists of war: Clausewitz and Sun Tzu.
Guests:
Andrew R. Wilson is the John A. van Beuren Chair of Asia-Pacific Studies. Professor Wilson has lectured at military colleges and civilian universities across the United States and around the world. The author of a number of books and articles on Chinese military history, Chinese sea power and Sun Tzu\u27s “The Art of War,” he is presently at work on “The Acme of Skill: Strategic Theory from Antiquity to the Information Age.” Professor Wilson is also featured on “The Great Courses,” with lecture series including “The Art of War”; “Masters of War: History’s Greatest Strategic Thinkers”; and “Understanding Imperial China: Dynasties, Life and Culture.”
Vanya Eftimova Bellinger earned a Ph.D. in history at King’s College, London. Bellinger is the author of Marie von Clausewitz: The Woman Behind the Making of On War (Oxford University Press USA, 2015). She is the winner of the 2016 Society for Military History Moncado Prize for her article, “The Other Clausewitz: Findings from the Newly Discovered Correspondence between Marie and Carl von Clausewitz.” Bellinger is the first scholar to work with the newly discovered correspondence between the Clausewitz couple. Before transitioning to academia, Bellinger worked as a journalist and international correspondent for various European outlets.https://digital-commons.usnwc.edu/strategy-matters/1000/thumbnail.jp
Functional Overreaching in Endurance Athletes: A Necessity or Cause for Concern?
No full textThere are variable responses to short-term periods of increased training load in endurance athletes, whereby some athletes improve without deleterious effects on performance, while others show diminished exercise performance for a period of days to months. The time course of the decrement in performance and subsequent restoration, or super compensation, has been used to distinguish between the different stages of the fitness–fatigue adaptive continuum termed functional overreaching (FOR), non-functional overreaching (NFOR) or overtraining syndrome. The short-term transient training-induced decrements in performance elicited by increases in training load (i.e. FOR) are thought be a sufficient and necessary component of a training program and are often deliberately induced in training to promote meaningful physiological adaptations and performance super-compensation. Despite the supposition that deliberately inducing FOR in athletes may be necessary to achieve performance super-compensation, FOR has been associated with various negative cardiovascular, hormonal and metabolic consequences. Furthermore, recent studies have demonstrated dampened training and performance adaptations in FOR athletes compared to non-overreached athletes who completed the same training program or the same relative increase in training load. However, this is not always the case and a number of studies have also demonstrated substantial performance super-compensation in athletes who were classified as being FOR. It is possible that there are a number of contextual factors that may influence the metabolic consequences associated with FOR and classifying this training-induced state of fatigue based purely on a decrement in performance may be an oversimplification. Here, the most recent research on FOR in endurance athletes will be critically evaluated to determine (1) if there is sufficient evidence to indicate that inducing a state of FOR is necessary and required to induce a performance super-compensation; (2) the metabolic consequences that are associated with FOR; (3) strategies that may prevent the negative consequences of overreaching.Full Tex
Herstory Writers Workshop
No full textExploring new internship opportunities is the key to engaging in a rich and meaningful education. The wisdom I have gleaned as an intern for Herstory Writers Workshop has enriched my life in ways I could never have imagined. Herstory Writers Workshop provides a community-based learning environment for its participants, which is one of the many reasons why I became a highly enthusiastic member of its organization. I am extremely passionate by the way in which Herstory instills in students and interns the confidence, skills, and support they need in order to propel forward into the next stages of their lives. Herstory provides a voice for individuals who aspire to share their personal stories of how they have successfully overcome difficult challenges. My goal, as an intern, was to provide students with the comfort, trust, and stability that they sought to obtain upon joining Herstory. Nicole Bellinger, the Salutatorian of the Class of 2016, states that, “Together, the students, interns, active members of Herstory, and myself have had the opportunity to incite change, express ourselves, overcome adversity, and perhaps most rewarding, motivate one another to push beyond our boundaries of limitation and rise above all that has held us down in the past.” Phillip Catapano, a criminal justice major at LIU- Post, proudly provides the following testimonial regarding this internship: “I will never forget my time with Herstory. Never before have I encountered such a comforting space for students and interns to share their stories
Strong, Fast, Fit, Lean, and Safe: A Positional Comparison of Physical and Physiological Qualities Within the 2020 Australian Women's Rugby League Team
No full textMinahan, C, Newans, T, Quinn, K, Parsonage, J, Buxton, S, and Bellinger, P. Strong, Fast, Fit, Lean, and Safe: A positional comparison of physical and physiological qualities within the 2020 Australian Women's Rugby League team. J Strength Cond Res XX(X): 000-000, 2021-The purpose of the present study was to report the physical and physiological characteristics of elite women Rugby League (RL) players. Thirty-nine women (25.6 ± 4.3 years, 171.3 ± 7.7 cm, 83.5 ± 13.9 kg) from the 2020 Australian women's RL squad were recruited for this study. Players were categorized as adjustables (n = 7), backs (n = 15), or forwards (n = 17) for analysis. Each player was assessed for anthropometry, body composition (dual-energy X-ray absorptiometry), speed (5, 10 and 20 m sprint times), lower-body power (countermovement jump), upper-body power (medicine ball throw and explosive push up force), estimated one repetition maximum (e1RM) bench press, squat and bench pull, isometric mid-thigh pull strength, eccentric knee flexor strength, isometric hip abduction and adduction, and intermittent endurance performance (30-15 intermittent fitness test; 30-15 IFT). Linear mixed models were performed to compare positional groups. Forwards were significantly heavier and had greater fat mass, fat-free mass, and body fat percentage compared with backs and adjustables (P < 0.01). Backs were faster over 20 m compared with forwards (P = 0.025), whereas forwards had a lower 30-15 IFT peak velocity and estimated V[Combining Dot Above]O2peak compared with backs and adjustables. Nonetheless, when including body mass in the model, there were no differences between groups in 30-15 IFT peak velocity. There were no significant differences in other variables. These results provide contemporary benchmark physical, physiological, and anthropometric data for elite women RL players, which can inform recruitment, selection, training, and testing.No Full Tex
The balancing act: Identifying multivariate sports performance using Pareto frontiers
No full textAthletes often require a mix of physical, physiological, psychological, and skill-based attributes that can be conflicting when competing at the highest level within their sport. When considering multiple variables in tandem, Pareto frontiers is a technique that can identify the observations that possess an optimal balance of the desired attributes, especially when these attributes are negatively correlated. This study presents Pareto frontiers as a tool to identify athletes who possess an optimal ranking when considering multiple metrics simultaneously. This study explores the trade-off relationship between batting average and strike rate as well as bowling strike rate, economy, and average in Twenty 20 cricket. Eight hundred ninety-one matches of Twenty 20 cricket from the men's (MBBL) and women's (WBBL) Australian Big Bash Leagues were compiled to determine the best batting and bowling performances, both within a single innings and across each player's Big Bash career. Pareto frontiers identified 12 and seven optimal batting innings performances in the MBBL and WBBL respectively, with nine and six optimal batting careers respectively. Pareto frontiers also identified three optimal bowling innings in both the MBBL and WBBL and five and six optimal bowling careers in MBBL and WBBL, respectively. Each frontier identified players that were not the highest ranked athlete in any metric when analyzed univariately. Pareto frontiers can be used when assessing talent across multiple metrics, especially when these metrics may be conflicting or uncorrelated. Using Pareto frontiers can identify athletes that may not have the highest ranking on a given metric but have an optimal balance across multiple metrics that are associated with success in a given sport
Characterising the movement patterns of women's beach volleyball using global positioning systems
No full textThe aim of this thesis was to describe the movement patterns of women’s beach volleyball using global positioning systems (GPS) technology. This aim was completed in two parts: Part A involved the investigation of the level of agreement between an emerging GPS system (VX Sport VX235 Log, Visuallex Sport International Ltd, Lower Hutt, New Zealand) and a well- established GPS system (Catapult MinimaxX S4, Catapult Innovations, Melbourne Australia). We recruited five semi-professional beach volleyball athletes who wore the two GPS units (sampling at 10 Hz) simultaneously during a training session which involved beach volleyball drills and simulated match-play. A paired sample t-test with statistical significant set to p<0.05 was applied to examine whether differences existed in the measurements of total distance (m), average speed (m∙min-1), max velocity (m∙s-1) and the distance (m) covered in five distinct velocity zones during a beach volleyball training session between the two different brands of GPS units. Significantly greater average speed (38.3 ± 5.66 m∙min-1, p = 0.009), and the distance covered between speeds of 4-8 km∙h-1 (248 ± 207 m, p = 0.008) and 16-20.5 km∙h-1 (8.78 ± 7.40 m, p = 0.006) were reported by the Catapult S4 units compared to the VX235 GPS units (35.9 ± 3.45 m∙min-1, 206 ± 168 m and 1.64 ± 2.62 m respectively), in conjunction with the VX235 units reporting a greater max velocity (4.37 ± 0.68 m∙s-1, p = 0.013) compared to the Catapult S4 units (4.07 ± 0.60 m∙s-1). These results demonstrate that differences exists between the emerging VX235 GPS system and the well-established Catapult S4 GPS system for measuring the movement patterns during beach volleyball, supporting the notion that further validation of GPS units against other practically applied and validated athlete movement trackers is required to further understand the ability of GPS systems to measure the movement patterns of beach volleyball.
Part B of this thesis involved the application of the 10 Hz VX235 GPS unit to quantify the movement patterns of women’s beach volleyball match-play. Specifically the VX235 GPS unit was worn by twenty female beach volleyball athletes during competition matches from the U23 Australian beach volleyball championship (n=10) and the Queensland Open tournament (n=10). The results form Part B of this thesis describe women’s beach volleyball athletes as covering a total distance of 555 ± 129 m and an average speed of 36.2 ± 3.2 m∙min-1, in addition to the majority of the distance covered occurred at speeds between 0-3.9 km∙h-1 (274 ± 63.6 m) and 3.9-7.8 km∙h-1 (203 ± 57.3) during match-play. The magnitude of these physical measures resulted in an average heart rate of 159 ± 12.0 bpm and 71.3 ± 30.4% of time with a heart rate ≤168 bpm. An independent sample t-test with statistical significant set to p5 points). A paired sample t-test with statistical significant set to p 5). In addition all physiological measures of heart rate displayed no significant difference between sets that ended with a small score margin and sets that ended with a large score margin with the exception of the percentage of time spent with a heart rate between 80-85% of each athletes age-predicted max heart rate which was significantly greater for sets that ended with a small score margin (25.8 ± 16.3%, p = 0.013) compared to sets that ended with a large score margin (16.0 ± 17.1%). The results from Part B of this thesis were the first to identify the movement patterns of women’s beach volleyball and provide insight into the presence of fatigue and the effect of score margin differential. The results provide information to assist in preparing women’s beach volleyball athletes for the demands they are likely to undertake during competitive match-play.Thesis (Masters)Master of Medical Research (MMedRes)School of Medical ScienceGriffith HealthFull Tex
GPS Data Analytics in Football: A Spotlight on Deceleration
No full textBackground: As technology has improved, the ability to gain data from player monitoring devices has become more prevalent in sport science, especially with the introduction of Global Positioning System (GPS) technology. We know that the ability to rapidly increase velocity is a key element of field-based sports such as football, which require repeated sprint efforts throughout a game. What is less intuitive is the importance of negative acceleration or “deceleration” to team-sport performance. Deceleration is important because it affords players the ability to change direction and avoid collisions. Furthermore, deceleration may be a significant contributor to muscle fatigue and damage, which is an important consideration for performance and recovery. The two predominant metrics used to describe deceleration profiles are the frequency of deceleration efforts and the distance covered whilst decelerating; however, there are flaws with both metrics when considering the deceleration movement. Similarly, as deceleration is a secondary movement to a preceding acceleration, deceleration is opportunistic and cannot be analysed in isolation.
Methods: Activity profiles were collected from twenty male football players competing in the Australian Hyundai A-League during 58 matches throughout two seasons (N = 368 observations). Match data were organised into ten 9-minute periods (i.e., P1: 0 - 9 min) and the time spent accelerating at moderate (1 to 2 m·s−2) and high (> 2 m·s−2) acceleration (ACCM and ACCH, respectively) and the time spent decelerating at moderate (-1 to -2 m·s−2) and high (< -2 m·s−2) deceleration (DECM and DECH, respectively) were quantified. Additionally, deceleration:acceleration and deceleration:high-velocity running ratios were also quantified to interrogate the opportunistic nature of deceleration activity throughout match play. A linear mixed model was used to determine the effects of time on the duration spent accelerating and decelerating, as well as the effect of position and formation on the duration spent accelerating and decelerating.
Results: All four acceleration and deceleration metrics decreased between 23 – 26% from the first 9-min interval to the last 9-min interval. There was a significant effect of time on each metric and each displayed negative logarithmic curves within both halves of football match play. When examining the ratios of deceleration to acceleration and high-velocity running, there was no change in the ratio between DECH duration and total acceleration duration (ACCH + ACCM), while the ratios between DECM duration and total acceleration duration, DECM duration and high-velocity running distance (> 14.4 km·h1), and DECH duration and high-velocity running distance increased as the match progressed.
Discussion: Using negative logarithmic curves to illustrate the acceleration and deceleration decay provides a novel methodological approach to quantify the high-intensity actions during football match play. The decrease in the duration of deceleration efforts throughout match play could simply be attributed to a lack of opportunity, as evident by the increase in the ratio of deceleration:acceleration and deceleration:high-velocity running. This conflicts with the conclusions of previous studies which suggest that deceleration ability is compromised in the latter periods of match play.
Practical Applications: Researchers and practitioners should consider the frequency and intensity of deceleration before making inferences regarding a decrease in a player’s ability to decelerate. By utilising negative logarithmic curves, practitioners can model the decay in acceleration and decelerations profiles. Finally, researchers and practitioners must be aware of the opportunistic nature of deceleration and monitor changes in the ratios of deceleration:acceleration and deceleration:high-velocity running, rather than relying on deceleration values in isolation.Thesis (Masters)Master of Medical Research (MMedRes)School of Medical ScienceGriffith HealthFull Tex
Muscle damage and metabolic responses to repeated-sprint running with and without deceleration
No full textMinahan, CL, Poke, DP, Morrison, J, and Bellinger, PM. Muscle damage and metabolic responses to repeated-sprint running with and without deceleration. J Strength Cond Res XX(X): 000–000, 2017—This study aimed to determine whether repeated-sprint running with deceleration aggravates markers of muscle damage or delays the recovery of performance compared with repeated-sprint running without deceleration. Fourteen male team-sport athletes performed 2 randomly ordered testing sessions on a nonmotorized treadmill with one session requiring participants to decelerate (TMd) within 4 seconds before stopping or immediately step to the side of the treadmill belt at the completion of each sprint (TMa). Peak and mean velocities, speed decrement, blood lactate concentrations, and oxygen uptake were monitored during the repeated-sprint running protocols. Countermovement vertical jump (CMJ) performance, perceived muscle soreness, sit-and-reach flexibility, plasma creatine kinase (CK), lactate dehydrogenase (LDH), and myoglobin (Mb) concentrations were quantified immediately before and after and 45 minutes, 24 and 48 hours after repeated-sprint running protocols. Although muscle damage was indicated by increases in CK, LDH, and Mb (p ≤ 0.05) in both groups, there was no significant effect of condition (TMa vs. TMd) on any of the measured performance or physiological variables (p > 0.05). The present study indicated that the removal of deceleration from repeated-sprint running on a nonmotorized treadmill has no effect on metabolism or performance during or after repeated-sprint running or markers of muscle damage.Griffith Health, School of Allied Health SciencesFull Tex
Quantifying the training-intensity distribution in middle-distance runners: The influence of different methods of training-intensity quantification
No full textPurpose: To compare the training-intensity distribution (TID) across an 8-week training period in a group of highly trained middle-distance runners employing 3 different methods of training-intensity quantification. Methods: A total of 14 highly trained middle-distance runners performed an incremental treadmill test to exhaustion to determine the heart rate (HR) and running speed corresponding to the ventilatory thresholds (gas-exchange threshold and respiratory-compensation threshold), as well as fixed rating of perceived exertion (RPE) values, which were used to demarcate 3 training-intensity zones. During the following 8 weeks, the TID (total and percentage of time spent in each training zone) of all running training sessions (N = 695) was quantified using continuous running speed, HR monitoring, and RPE. Results: Compared with the running-speed-derived TID (zone 1, 79.9% [7.3%]; zone 2, 5.3% [4.9%]; and zone 3, 14.7% [7.3%]), HR-demarcated TID (zone 1, 79.6% [7.2%]; zone 2, 17.0% [6.3%]; and zone 3, 3.4% [2.0%]) resulted in a substantially higher training time in zone 2 (effect size ± 95% confidence interval: -1.64 ± 0.53; P < .001) and lower training time in zone 3 (-1.59 ± 0.51; P < .001). RPE-derived TID (zone 1, 39.6% [8.4%]; zone 2, 31.9% [8.7%]; and zone 3, 28.5% [11.6%]) reduced time in zone 1 compared with both HR (-5.64 ± 1.40; P < .001) and running speed (-5.69 ± 1.9; P < .001), whereas time in RPE training zones 2 and 3 was substantially higher than both HR- and running-speed-derived zones. Conclusion: The results show that the method of training-intensity quantification substantially affects computation of TID.Full Tex
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