Marijke Welvaert

University of Canberra · Research Institute for Sport and Exercise

Objective: To examine whether measures of neuromuscular control and proprioceptive acuity were predictive of falls in an older community-dwelling population and to develop a multivariate prediction model. Methods: Fifty-eight adults aged above 60 living independently in the community were recruited for a prospective falls study. On entry, they u...

Analysing the ball movement patterns of team invasion sports provides practical insight into successful strategies by identifying how and where to move the ball to create goal scoring opportunities. The aim of this study was to analyse the entropy and spatial distribution of ball movement patterns in international field hockey teams. A notational a...

The goal of performance analysis is to capture the multitude of factors that affect sports strategy, and present them in an informative, interpretable, and accessible format. The aim of this study was to outline a performance analysis process in field hockey that captures, analyses and visualises strategy in layers of detail culminating in the crea...

Objective: To ensure accurate data capture for a fall study through a system of daily contact with participants. Methods: Fifty-eight adults older than 60 years of age and living independently in the community in Canberra, Australia, were recruited for a prospective fall study. We adopted a system of daily contact with study participants for at...

Characterising a team's game style is a performance analysis approach that captures game events, and groups them into profiles using clustering techniques to identify the consistent (and winning) strategies a team implements. The aim of this study was to identify the game styles of international hockey teams. Video footage from the 2019 Pro League...

Background Athlete health, training availability and performance can be impeded due to Relative Energy Deficiency in Sport (RED-S). Development of RED-S is underpinned by low energy availability (LEA), however its natural history is yet to be defined. Objective To quantify the prevalence of issues previously described in association with RED-S in...

Purpose: Psychological stress is reported to be an important contributor to reduced sleep quality and quantity observed in elite athletes. The purpose of this study was to explore the association between psychological stress and sleep and to identify if specific aspects of sleep are disturbed. Methods: One hundred thirty-one elite athletes (mean...

Purpose: Determine the efficacy of α-lactalbumin (A-LAC) supplementation for improving sleep and performance recovery following simulated evening competition in female athletes. Methods: Sixteen trained females (mean ± SD; age 27 ± 7 years; mass 62 ± 10 kg; stature 167 ± 8 cm) participated in this randomised double-blind three-arm crossover stud...

Proprioceptive ability - the sense of where body parts are located in space - is one of many factors thought to affect falls risk among the elderly. Active movement extent discrimination is an approach to measuring proprioception that is administered in an ecologically valid testing environment to better reflect the exercise of proprioceptive skill...

Field hockey is an evolving sport, but it is unclear whether performance analysis techniques are reflective of current best practice. The objective of this review was to identify performance analysis methods used in field hockey, assess their practicality, and provide recommendations on their implementation in the field. A systematic search of the...

The Active Movement Extent Discrimination Apparatus (AMEDA) has been used for measuring proprioception at various joints in the body for more than two decades. The utility of this instrument for discriminating groups has been reported in terms of an area under the curve (AUC) derived from an absolute identification test. This metric has supported s...

The automatic segmentation of Achilles tendon tissues is one of the preliminary steps towards creating a tool for diagnosing, prognosing, or monitoring changes in tendon organization over time. Manual delineation is the current approach of identifying Achilles region-of-interest (ROI), it is a tedious and time-consuming task. In this respect, the c...

Purpose: The risk of exercise-induced endotoxemia is increased in the heat and is primarily attributable to changes in gut permeability resulting in the translocation of lipopolysaccharides (LPS) into the circulation. The purpose of this study was to quantify the acute changes in gut permeability and LPS translocation during submaximal continuous a...

Background: Cardiovascular disease (CVD) remains the largest cause of death in breast cancer survivors. The aim of this study was to explore the impact of exercise intensity on aerobic fitness and autonomic cardiac regulation (heart rate variability (HRV)) and salivary biomarkers of the stress systems (HPA-axis, cortisol; sympathetic nervous system...

[This corrects the article DOI: 10.1371/journal.pone.0234027.].

The objective of this review was to systematically describe the traditional and contemporary data capture and analytic methods employed in performance analysis research in team invasion sports, evaluate the practicality of these methods, and formulate practical recommendations on methods for analysing tactics and strategies in team invasion sports....

Introduction We repeated our study of intensified training on a ketogenic low-carbohydrate (CHO), high-fat diet (LCHF) in world-class endurance athletes, with further investigation of a “carryover” effect on performance after restoring CHO availability in comparison to high or periodised CHO diets. Methods After Baseline testing (10,000 m IAAF-san...

Objectives Glucocorticoids are commonly prescribed in medicine. When administered via certain routes, glucocorticoids are prohibited for incompetition use by WADA. The glucocorticoid prescribing habits of sports medicine doctors have not been reported. Methods An online survey was distributed internationally to physicians working in high-performan...

Objectives: To investigate diet-exercise interactions related to bone markers in elite endurance athletes after a 3.5-week ketogenic low-carbohydrate, high-fat (LCHF) diet and subsequent restoration of carbohydrate (CHO) feeding. Methods: World-class race walkers (25 male, 5 female) completed 3.5-weeks of energy-matched (220 kJ·kg·d−1) high CHO (HC...

Data streams arising from citizen reporting activities continue to grow, yet the information content within these streams remains unclear, and methods for addressing the inherent reporting biases little developed. Here, we quantify the major influence of physical insect features (colour, size, morphology, pattern) on the propensity of citizens to u...

Purpose: Habitual intense exercise may increase the incidence of upper respiratory symptoms (URS) in elite athletes. This study investigated whether immune gene expression could identify gene markers that discriminate athletes with a higher prevalence of URS. Methods: This cross-sectional analysis of elite Australian athletes from various sports...

Background Behavioral treatment strategies improve adherence to lifestyle intervention for adults with obesity, but can be time and resource intensive when delivered via traditional face-to-face care. This study aimed to investigate the efficacy and optimal timing of using telephone calls and text message as adjunctive tools to support a community-...

Objectives: To contribute to our understanding of the drivers of body composition during adolescence we sought to employ valid and reliable measures to investigate cross-sectional and longitudinal relationships between percentage body fat (%BF) and physical activity (PA), moderate and vigorous PA (MVPA), sedentary time (ST), total energy, sugar an...

Urinary excretion of hydroxyproline (Hyp), abundant in collagen protein, may serve as a biomarker of habitual collagen intake, assisting with investigations of the current interest in the role of dietary collagen intake in supporting the synthesis of collagenous body tissues. This study investigated the time course of urinary Hyp excretion in “free...

Background: The risk of sustaining a subsequent injury is elevated in the weeks after return to play (RTP) from an index injury. However, little is known about the magnitude, duration, and nature by which subsequent injury risk is increased. Purpose: To quantify and describe the risk of injury in a 12-week period after RTP from an index injury i...

Objectives: Adhering to a low carbohydrate (CHO) high fat (LCHF) diet can alter markers of iron metabolism in endurance athletes. This investigation examined the re-introduction of CHO prior to, and during exercise on the iron-regulatory response to exercise in a homogenous (in regard to serum ferritin concentration) group of athletes adapted to a...

International-level swimmers periodize their training to qualify for major championships, then improve further at these events. However the effects of various factors that could impact on performance progressions have not been described systematically. Purpose To quantify the pattern of change in performance between season best qualifying time and...

Purpose: To assess pacing strategies using prescribed and self-selected inter-set rest periods and their influence on performance in strength trained athletes. Methods: Sixteen strength-trained male athletes completed three randomised heavy-strength training sessions (five sets, five repetitions) with different inter-set rest periods. The inter-...

Purpose: Determine if a series of trials with fraction of inspired oxygen (FiO2) content deception could improve 4000-m cycling time-trial (TT) performance. Methods: Fifteen trained male cyclists (mean ± SD: body mass 74.2 ± 8.0 kg; peak oxygen uptake 62 ± 6 mL.kg-1.min-1) completed six, 4000-m cycling TTs in a semi-randomised order. After a fam...

The current pilot study investigates whether oral supplementation of specific collagen peptides improves symptoms and tendon vascularisation in patients with chronic mid-portion Achilles tendinopathy in combination with structured exercise. Participants were given a placebo or specific collagen peptides (TENDOFORTE®) in combination with a bi-daily...

Objectives: The role of neovascularisation in tendinopathy is still poorly understood, potentially due to technical limitations of conventional power Doppler ultrasound. This study aimed to investigate the association between contrast-enhanced ultrasound (CEUS) microvascular volume (MV), Victorian Institute of Sports Assessment-Achilles (VISA-A) s...

Purpose: The short-term restriction of carbohydrate (CHO) can potentially influence iron regulation via modification of post-exercise interleukin-6 (IL-6) and hepcidin levels. This study examined the impact of a chronic ketogenic low CHO-high fat (LCHF) diet on iron status and iron-regulatory markers in elite athletes. Methods: International-lev...

Purpose: To determine the effect of altitude training at 1600 and 1800 m on sea-level (SL) performance in national-level runners. Methods: After 3 wk of SL training, 24 runners completed a 3-wk sojourn at 1600 m (ALT1600, n = 8), 1800 m (ALT1800, n = 9), or SL (CON, n = 7), followed by up to 11 wk of SL racing. Race performance was measured at S...

Objectives: Despite evidence suggesting caution, employment of body mass index (BMI, kgm-2) as a proxy for percentage of body fat (PFat) in longitudinal studies of children and adolescents remains commonplace. Our objective was to test the validity of change in BMI as a proxy for change in PFat measured by dual-energy X-ray absorptiometry (DXA) du...

Cycle training is an important training modality of elite rowers. Cycling is the preferred alternative to on-water and ergometer rowing as it provides a reduction in compressive forces on the thoracic cage and upper extremities while still creating a local and central acclimation to endurance training. It is hypothesised, however, that there will b...

Objectives: The primary purpose of this study was to describe an early detection and management strategy when monitoring in-season hip and groin strength, health and function in soccer. Secondly to compare pre-season to in-season test results. Design: Longitudinal cohort study. Methods: Twenty-seven elite male youth soccer players (age: 15.07±...

Although short (up to 3 days) exposure to major shifts in macronutrient intake appears to alter acid-base status, the effects of sustained (>1 week) interventions in elite athletes has not been determined. Using a non-randomized, parallel design, we examined the effect of adaptations to 21 days of a ketogenic low carbohydrate high fat (LCHF) or per...

Background Recent research has demonstrated decreases in resting metabolic rate (RMR), body composition and performance following a period of intensified training in elite athletes, however the underlying mechanisms of change remain unclear. Therefore, the aim of the present study was to investigate how an intensified training period, designed to e...

Subjective feelings of appetite assessment via 1–10 Likert visual analogue scale. (JPG)

Linear mixed model data for the energy intake model. Data are presented as the F-statistic and p-value, and a +/- symbol to denote a positive or negative linear association over time, where relevant. Where a significant linear relationship is observed, * denotes p < 0.05, ** denotes p < 0.01, *** denotes p < 0.001. (DOCX)

Raw data: Appetite. Data are presented as individual values for each time point, and group mean ± SD. (DOCX)

Raw data: Cycling performance. Data are presented as individual values for each time point, and group mean ± SD. (DOCX)

Raw data: Mood questionnaires—Multicomponent training distress scale. Data are presented as individual values for each time point, and group mean ± SD. (DOCX)

Raw data: Mood questionnaires—RESTQ-52 sport. Data are presented as individual values for each time point, and group mean ± SD. (DOCX)

Raw data: Absolute RMR. Data are presented as individual values for each time point, and group mean ± SD. (DOCX)

Raw data: Relative RMR. Data are presented as individual values for each time point, and group mean ± SD. (DOCX)

Raw data: Minute ventilation [VE(STPD)]. Data are presented as individual values for each time point, and group mean ± SD. (DOCX)

Raw data: Biochemical markers PRE-POST ergometer warm-up. Data are presented as individual values for each time point, and group mean ± SD. (DOCX)

Raw data: Heart rate variability. Data are presented as individual values for each time point, and group mean ± SD. (DOCX)

Linear mixed model data for the body composition model. Data are presented as the F-statistic and p-value, and a +/- symbol to denote a positive or negative linear association over time, where relevant. Where a significant linear relationship is observed, * denotes p < 0.05, ** denotes p < 0.01, *** denotes p < 0.001. (DOCX)

Linear mixed model data for the biochemical markers model. Data are presented as the F-statistic and p-value, and a +/- symbol to denote a positive or negative linear association over time, where relevant. Where a significant linear relationship is observed, * denotes p < 0.05, ** denotes p < 0.01, *** denotes p < 0.001. (DOCX)

Linear mixed model data for the heart rate variability model. Data are presented as the F-statistic and p-value, and a +/- symbol to denote a positive or negative linear association over time, where relevant. Where a significant linear relationship is observed, * denotes p < 0.05, ** denotes p < 0.01, *** denotes p < 0.001. (DOCX)

Linear mixed model data for the cycling performance model. Data are presented as the F-statistic and p-value, and a +/- symbol to denote a positive or negative linear association over time, where relevant for the Modified Power Profile sprints and 4000m TT. Where a significant linear relationship is observed, * denotes p < 0.05, ** denotes p < 0.01...

Linear mixed model data for the mood questionnaire tesponses model. Data are presented as the F-statistic and p-value, and a +/- symbol to denote a positive or negative linear association over time, where relevant for a) the MTDS and b) RESTQ-52 Sport. Where a significant linear relationship is observed,* denotes p < 0.05, ** denotes p < 0.01, ***...

Linear mixed model data for the appetite model. Data are presented as the F-statistic and p-value, and a +/- symbol to denote a positive or negative linear association over time, where relevant. Where a significant linear relationship is observed, * denotes p < 0.05, ** denotes p < 0.01, *** denotes p < 0.001. (DOCX)

Raw data: Body composition. Data are presented as individual values for each time point, and group mean ± SD. (DOCX)

Raw data: Energy intake. Data are presented as individual values for each time point, and group mean ± SD. (DOCX)

We document predation of aestivating bogong moths (Agrotis infusa) by wild pigs (Sus scrofa) at a location in the Australian Alps. This is the first known record of pigs preying on bogong moths. Wild pigs are recent colonisers of the region, though already the population appears seasonally habituated to foraging on aestivating moths. This is indica...

Objective Establish the prevalence of illness symptoms, poor sleep quality, poor mental health symptoms, low energy availability and stress-recovery state in an Olympic cohort late in the 3 months prior to the Summer Olympic Games. Methods Olympic athletes (n=317) from 11 sports were invited to complete questionnaires administered 3 months before...

Studies examining pacing strategies during 4000m cycling time-trials (TTs) typically ensure participants are not pre-fatigued, however competitive cyclists often undertake TTs when already pre-fatigued. This study aimed to determine how TT pacing strategies and sprint characteristics of cyclists change during an intensified training period (mesocyc...

The purpose of this study was to investigate the effect of a congested international tournament match schedule on adductor strength and pain in elite youth football players. Twenty-two male players (age: 15.53 ± 0.48 years, height: 174.87 ± 7.59 cm, weight: 67.45 ± 7.40 kg) were included. The 5-second adductor squeeze strength was captured daily us...

Objectives: To investigate the effects of experimental adductor pain on the pain referral pattern, mechanical sensitivity and muscle activity during common clinical tests. Design: Repeated-measures design. Methods: In two separate sessions, 15 healthy males received a hypertonic (painful) and isotonic (control) saline injection to either the a...

Objectives Illness can disrupt training and competition performance of athletes. Few studies have quantified the relative contribution of the known medical, behavioural and lifestyle risk factors. Design Cross-sectional Methods Olympic athletes from 11 sports (n = 221) were invited to complete questionnaires administered nine months before the Ri...

Compared to applications that trigger massive information streams, like earthquakes and human disease epidemics, the data input for agricultural and environmental biosecurity events (ie. the introduction of unwanted exotic pests and pathogens), is expected to be sparse and less frequent. To investigate if Twitter data can be useful for the detectio...

Background Illnesses affect the ability of an athlete to perform. Few studies investigate risk factors in athletes across disciplines. Objective To investigate risk factors for illness in athletes preparing for the Olympic Games. Design Cross-sectional. Setting Australian athletes eligible for selection for the Olympic Games. Participants 317 a...

Poor adherence to lifestyle intervention remains a key factor hindering treatment effectiveness and health outcomes for adults with obesity. The aim of this systematic review and meta-analysis is to determine if behavioural treatment strategies (e.g. goal setting, motivational interviewing, relapse prevention, cognitive restructuring etc.) improve...

In search of their optimal performance athletes will alter their pacing strategy according to intrinsic and extrinsic physiological, psychological and environmental factors. However, the effect of some of these variables on pacing and exercise performance remains somewhat unclear. Therefore, the aim of this meta-analysis was to provide an overview...

Citizen science and crowdsourcing have been emerging as methods to collect data for surveillance and/or monitoring activities. They could be gathered under the overarching term citizen surveillance. The discipline, however, still struggles to be widely accepted in the scientific community, mainly because these activities are not embedded in a quant...

Key points Three weeks of intensified training and mild energy deficit in elite race walkers increases peak aerobic capacity independent of dietary support. Adaptation to a ketogenic low carbohydrate, high fat (LCHF) diet markedly increases rates of whole‐body fat oxidation during exercise in race walkers over a range of exercise intensities. The i...

Introduction Illness has the potential to ruin Olympic campaigns. There have been many studies examining mechanisms of illness in athletes with emerging evidence indicating an increased risk of illness in some athlete cohorts. Despite this body of research few systematic risk factors have been clearly identified across multiple domains of health or...

Introduction The amount of energy remaining to support body functions after the kilojoule cost of exercise is subtracted from dietary energy intake is termed “energy availability”. Low energy availability can occur when an athlete restricts their energy intake and/or increases the volume or intensity of training, with the consequence that there is...

Introduction Few studies have quantified the relative contribution of medical and immunological risk factors. Low salivary IgA and 25(OH)vitamin D deficiency have been suggested as risk factors for illness. Methods Olympic athletes from 15 sports (n=317) were invited to participate in screening of 25(OH) vitamin D levels in non-fasting venous blood...