Journal Articles
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Item Menstrual blood loss as an initial trigger for adaptation of iron metabolism in eumenorrheic female athletes—An exploratory study(Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society, 2025-08-26) Nolte S; Maier C; Klügel S; Weyh C; Hacker S; Badenhorst C; Krüger KIron deficiency is a risk factor for impaired performance and recovery. While exercise-related iron losses are well-documented, the role of menstrual blood loss (MBL) as a physiological trigger of iron regulation remains underexplored. This study examined whether MBL in eumenorrheic female athletes induces measurable hematological and iron-related responses, accounting for sex hormone fluctuations. Ten regional-level football players underwent menstrual cycle tracking and venous blood sampling in both the early follicular and mid-luteal phases. Hematological parameters, iron markers (ferritin and hepcidin), erythropoietic markers (erythropoietin and reticulocytes), and inflammatory markers (myeloperoxidase [MPO] and C-reactive protein [CRP]) were measured. MBL was assessed using the Pictorial Blood Loss Assessment Chart (PBAC). Analyses included descriptive statistics, correlation, and linear mixed modeling. MBL was significantly associated with ferritin (β = −0.289, p = 0.001), reticulocyte counts (β = 0.004, p = 0.019), and reticulocyte production index (β = 0.004, p = 0.027). MPO and CRP showed inverse correlations with MBL, suggesting potential immunomodulatory effects. No interaction between MBL and cycle phase was found. MBL appears to stimulate compensatory erythropoiesis in female athletes, largely independent of hormonal phase. Incorporating MBL assessment into athlete monitoring may support individualized strategies to maintain iron balance and optimize performance.Item VLamax Correlates Strongly With Glycolytic Performance(Taylor and Francis Group on behalf of SHAPE America, 2025-04-18) Clark B; Macdermid PWVLamax estimates an athlete’s maximal-glycolytic rate. This study aimed to determine the relationships between the VLamax and cycle ergometry efforts with a high-glycolytic energy contribution and the influence of VLamax and VO2max on respiratory compensation point. Eleven national-international endurance cyclists (VO2max = 70.7 ± 5.9 ml·kg−1·min−1) completed a 15-s isokinetic-test with pre- and postlactate measurements to determine VLamax, a 1-min maximal effort, and a ramp test to exhaustion in a single test session. The main findings showed strong relationships between VLamax and the mean absolute (r = 0.83, p =.002) and relative (r = 0.88, p =.0004) power during the lactic interval of the 15-s isokinetic-test. This relationship weakened when comparing VLamax with mean absolute (r = 0.52, p =.098) and relative (r = 0.29, p =.393) power during a 1-min maximal effort. Combining the VLamax and VO2max data through multiple regression resulted in a positive effect on the estimation of respiratory compensation point. It was concluded that the VLamax is a relevant indicator of maximal glycolytic rate. However, this metric currently lacks scientific validation as an accurate estimate of glycolytic rate and provides minimal extra information over using the power output from the isokinetic test alone. Practitioners may simply measure power over glycolytically demanding efforts to understand the maximal glycolytic rate of their athletes.Item Editorial: Advancements in cycling performance enhancement strategies for cyclists: from amateurs to elite(Frontiers Media S A, 2025-03-10) Polanco A; Macdermid PW; Berisha M; Girard OItem Impact of Technical-Tactical and Physical Performance on the Match Outcome in Professional Soccer: A Case Study(Academy of Physical Education in Katowice, 2024-07-17) Barthelemy B; Ravé G; Govindasamy K; Ali A; Del Coso J; Demeaux J; Bideau B; Zouhal HMatch outcomes and championship rankings are the consequence of the team’s technical, tactical, and physical variables. This study aimed to compare physical and modern technical-tactical performance variables between matches with different outcomes for a professional soccer team. Total distance covered, distance covered between 20.0 and 25.0 km/h, and at > 25.0 km/h, distance covered at ≥ 3 m/s2 and at ≤ −3 m·s−2 along with several modern technical-tactical variables (expected goals in favor (xG) and against (xGA), expected goals chain in favor (xGC) and against (xGCA) and passes per defensive action (PPDA)) were collected for 71 soccer matches during the 2020/2021 and 2021/2022 seasons from a team competing in the French Ligue 2. These technical-tactical and running performance variables were obtained by a validated video tracking system (OPTA) and their values per match were compared depending on the match outcome which was categorized as “loss” (L), “draw” (D) or “win” (W). No significant differences were observed for the different running metrics depending on the match outcome. However, significant differences were observed for xGA (0.70 ± 0.39 vs. 1.24 ± 0.59; pbonferroni= 0.004) and xGCA (5.38 ± 2.78 vs. 10.92 ± 6.18; pbonferroni = 0.002) between wins and losses, respectively. Additionally, there was a weak, but significant correlation between xGCA and distance covered in acceleration (r = 0.255; p = 0.032) and deceleration (r = 0.237; p = 0.047). In conclusion, while our study found associations between technical-tactical variables and match outcomes, causality cannot be inferred. Improved technical-tactical performance may positively impact the match result, especially by the reduction of the opposing team's goal expectancy. On the contrary, running performance variables showed no associations with the match outcome.Item Pasture Performance: Perspectives on Plant Persistence and Renewal in New Zealand Dairy Systems(MDPI (Basel, Switzerland), 2024-08) Cartmill AD; Donaghy DJ; Hou FPasture systems dominate the landscape of Aotearoa, New Zealand, and are an integral component of sustainable and resilient livestock production. Predicting the response, performance, and dynamics of pasture species and adapting management practices is key to the long-term economic and environmental sustainability and resilience of the agricultural sector. However, there is limited information on the long-term productivity, performance, and persistence of forage cultivars and species for pasture production systems, particularly when linked to grazing and animal performance. Here, we sought to reduce scientific uncertainty, inform modelling efforts, and contribute to a predictive framework for understanding pasture performance, persistence, and renewal. Inter-annual pasture renewal (direct drilling and cultivation) rates vary by region and year, reflecting both opportunity and problem-based drivers, with the highest pasture renewal rates in Waikato and Canterbury on the North and South Island, respectively.Item The Effects of GreenShell Mussel Powder (Brand-Named PERNAULTRA) on Physical Performance and Subjective Pain, Symptoms, and Function Measures in Knee Osteoarthritis: A 6-Mo Randomized, Double-Blind, Placebo-Controlled Trial(Elsevier Inc. on behalf of American Society for Nutrition, 2024-04) Slade CAJ; Kruger MC; Miller MR; Mazahery H; Beck KL; Conlon CA; Von Hurst PRBackground: Osteoarthritis (OA) can cause disability and reduce quality of life (QoL). Objectives: This study aimed to determine whether GreenShell mussel (GSM) powder (PERNAULTRA) consumption was more effective than placebo at improving physical performance and subjective measures of symptoms and function in adults with early signs of knee OA. Methods: The Researching Osteoarthritis and GSM study was a 6-mo randomized, double-blind, placebo-controlled trial in adults aged 55–80 y, screened for signs of OA (n = 120, 65.9 ± 6.43 y, 63% female). Participants consumed either 3 g of powdered whole GSM or placebo (pea protein) daily. Baseline and end data collection included 30-s chair stand, stair test, 40-m fast-paced walk test, Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire categorized into 5 subscales [pain (P), symptoms except pain (S), function in activities of daily living (ADL), function in sports/recreation (SP), and QoL], a measure of Intermittent and Constant Osteoarthritis Pain, and visual analog scale of pain and symptoms. Results: Visual analog scale symptoms showed a significantly greater reduction in percentage change for GSM than that for placebo [−28.1 (−59.2, 43.2) compared with 0.00 (−28.6, 100); P = 0.03]. Further, a trend for improvement in percentage change for GSM compared with placebo was seen in 40m fast-paced walk [2.51 (−3.55, 8.12) compared with 0.20 (−6.58, 4.92); P = 0.09], KOOS-SP [11.4 (−4.48, 27.0) compared with 0.00 (−11.1, 17.7); P = 0.09], and Intermittent and Constant Osteoarthritis Pain intermittent pain scale [−27.7 (−77.3, 0.00) compared with −14.6 (−50.0, 36.4); P = 0.08]. In those with body mass index (BMI; in kg/m2) <25, GSM consumption significantly improved KOOS-S compared with placebo [6.35 (3.49, 12.7) compared with 0.00 (−4.65, 4.49); P = 0.03] and showed a trend for improvement in KOOS-ADL [3.29 (1.01, 8.79) compared with 1.01 (−5.75, 4.30); P = 0.07]. Those with BMI of ≥25, consuming GSM showed a trend for improvement in KOOS-SP [13.6 (−4.76, 33.3) compared with 0.00 (−12.5, 20.0); P = 0.07]. Conclusions: This research suggests consumption of GSM has potential to alleviate symptoms and improve functionality in OA. This trial was registered at Clinical Trial Registry as ACTRN12620001112954p (https://www.anzctr.org.au/ACTRN12620001112954p.aspx).Item Breeding Ewe Lambs: An Australasian Perspective(MDPI (Basel, Switzerland), 2022-11-19) Kenyon PR; Corner-Thomas RAA number of potential advantages have been identified for breeding ewe lambs at 7 to 9 months of age, including increased lifetime productivity and profitability. However, breeding at this young age in extensive pastoral systems, such as in Australasia, can be associated with a number of disadvantages resulting in uptake of this management procedure being relatively low. This review highlights the known differences between ewe lamb and mature ewe reproductive performance, thus differing in their management. The review then summaries the scientific literature of factors that affect ewe lamb reproductive success, with a focus on recent studies conducted under extensive pasture-based conditions in Australasia. In particular, this review outlines the importance of ewe lamb live weight and body condition score on their productivity. The potential long-term consequences of breeding a ewe lamb at a young age in terms of her future success and that of her offspring to weaning are briefly outlined. In addition, the potential impacts of selecting progeny born to ewe lambs as future replacement ewes are discussed. Throughout this review, optimal management guidelines from prior to breeding the ewe lambs until rebreeding at 2 years of age are provided. Lastly, areas requiring future research are identified and discussed.Item A performative-performance analytical approach: Infusing butlerian theory into the narrative-discursive method(SAGE Publications (UK and US), 2013-10-01) Morison T; Macleod CJudith Butler’s theory of performativity provides gender theorists with a rich theoretical language for thinking about gender. Despite this, Butlerian theory is difficult to apply, as Butler does not provide guidance on actual analysis of language use in context. In order to address this limitation, we suggest carefully supplementing performativity with the notion of performance in a manner that allows for the inclusion of relational specificities and the mechanisms through which gender, and gender trouble, occur. To do this, we turn to current developments within discursive psychology and narrative theory. We extend the narrative-discursive method proposed by Taylor and colleagues, infusing it with Butlerian theory in order to fashion a dual analytical lens, which we call the performativity-performance approach. We provide a brief example of how the proposed analytical process may be implemented.Item Measurement error of self-paced exercise performance in athletic women is not affected by ovulatory status or ambient environment(American Physiological Society, 2021-11) Zheng H; Badenhorst CE; Lei T-H; Muhamed AMC; Liao Y-H; Amano T; Fujii N; Nishiyasu T; Kondo N; Mündel TMeasurement error(s) of exercise tests for women are severely lacking in the literature. The purpose of this investigation was to 1) determine whether ovulatory status or ambient environment were moderating variables when completing a 30-min self-paced work trial and 2) provide test-retest norms specific to athletic women. A retrospective analysis of three heat stress studies was completed using 33 female participants (31 ± 9 yr, 54 ± 10 mL·min−1·kg−1) that yielded 130 separate trials. Participants were classified as ovulatory (n = 19), anovulatory (n = 4), and oral contraceptive pill users (n = 10). Participants completed trials ∼2 wk apart in their (quasi-) early follicular and midluteal phases in two of moderate (1.3 ± 0.1 kPa, 20.5 ± 0.5°C, 18 trials), warm-dry (2.2 ± 0.2 kPa, 34.1 ± 0.2°C, 46 trials), or warm-humid (3.4 ± 0.1 kPa, 30.2 ± 1.1°C, 66 trials) environments. We quantified reliability using limits of agreement, intraclass correlation coefficient (ICC), standard error of measurement (SEM), and coefficient of variation (CV). Test-retest reliability was high, clinically valid (ICC = 0.90, P < 0.01), and acceptable with a mean CV of 4.7%, SEM of 3.8 kJ (2.1 W), and reliable bias of −2.1 kJ (−1.2 W). The various ovulatory status and contrasting ambient conditions had no appreciable effect on reliability. These results indicate that athletic women can perform 30-min self-paced work trials ∼2 wk apart with an acceptable and low variability irrespective of their hormonal status or heat-stressful environments. NEW & NOTEWORTHY This study highlights that aerobically trained women perform 30-min self-paced work trials ∼2 wk apart with acceptably low variability and their hormonal/ovulatory status and the introduction of greater ambient heat and humidity do not moderate this measurement error.Item Assessment of Changes in Physiological Markers in Different Body Fluids at Rest and after Exercise(MDPI (Basel, Switzerland), 2022-11-05) Jesuthasan A; Ali A; Lee JKW; Rutherfurd-Markwick KPhysiological and biological markers in different body fluids are used to measure the body's physiological or pathological status. In the field of sports and exercise medicine, the use of these markers has recently become more popular for monitoring an athlete's training response and assessing the immediate or long-term effects of exercise. Although the effect of exercise on different physiological markers using various body fluids is well substantiated, no article has undertaken a review across multiple body fluids such as blood, saliva, urine and sweat. This narrative review aims to assess various physiological markers in blood, urine and saliva, at rest and after exercise and examines physiological marker levels obtained across similar studies, with a focus on the population and study methodology used. Literature searches were conducted using PRISMA guidelines for keywords such as exercise, physical activity, serum, sweat, urine, and biomarkers, resulting in an analysis of 15 studies for this review paper. When comparing the effects of exercise on physiological markers across different body fluids (blood, urine, and saliva), the changes detected were generally in the same direction. However, the extent of the change varied, potentially as a result of the type and duration of exercise, the sample population and subject numbers, fitness levels, and/or dietary intake. In addition, none of the studies used solely female participants; instead, including males only or both male and female subjects together. The results of some physiological markers are sex-dependent. Therefore, to better understand how the levels of these biomarkers change in relation to exercise and performance, the sex of the participants should also be taken into consideration.