Florentina Johanna Hettinga

Vrije Universiteit Amsterdam | VU · Department of Human Movement Science

Purpose: To explore fatigue and physical activity behavior experiences and management, with an emphasis on activity pacing among adults with chronic conditions. Materials and methods: Semi-structured interviews were conducted with 15 adults with chronic conditions and the symptoms of chronic fatigue who had either received or not received fatigu...

Elite para-cycling needs an overview of relevant and valid research to better understand and improve performance and to develop the sport, using evidence-based decision making. The aim of this scoping review was to 1) provide a research overview of performance and performance determining factors in elite para-cycling to aid coaches and elite athlet...

Background For athletes, overcoming obstacles in challenging situations like pandemic home training is crucial. Strategies and approaches in this context are not well-documented. Our study aims to investigate such a scenario from a performance standpoint, based on a major global crisis: the COVID-19 pandemic and lockdown. Methods This cross-sectio...

Purpose : This study determined the evolution of performance and pacing for each winner of the men’s Olympic 1500-m running track final from 1924 to 2020. Methods : Data were obtained from publicly available sources. When official splits were unavailable, times from sources such as YouTube were included and interpolated from video records. Final ti...

Purpose: This focus group study aimed to explore experiences and perceptions on post-stroke fatigue guidance in Dutch rehabilitation and follow-up care among people/patients with stroke and health professionals. Methods: Ten persons with stroke and twelve health professionals with different professions within stroke rehabilitation or follow-up c...

Purpose. In competitive sports, optimizing performance is the key. An interesting venue to explore is to consider drafting as a pacing strategy. The purpose of this study is to identify the magnitude of drafting benefits for biomechanical, physiological, and psychobiological parameters in and between athletes in cycling, kayaking, running, skating,...

A large body of evidence has shown that placebo effects of dietary supplements can improve sport performance. However, very few studies are conducted outside of the laboratory. This is important given that placebo effects may be more likely to be induced during highly controlled, artificial environments in the presence of a researcher. In the past...

Background People with physical disabilities and/or chronic diseases tend to have an inactive lifestyle. Monitoring physical activity levels is important to provide insight on how much and what types of activities people with physical disabilities and/or chronic diseases engage in. This information can be used as input for interventions to promote...

Fatigue is barrier of physical activity participation in adults with chronic conditions. However, physical activity alleviates fatigue symptoms. This systematic review and meta-analysis aimed to (1) synthesise evidence from randomised controlled trials (RCTs) exploring the effects of physical activity interventions on fatigue reduction and (2) eval...

INTRODUCTION: Adults with chronic conditions often experience significant fatigue, which is a barrier to physical activity participation and negatively impacts their health-related quality of life and physical function. Studies have found that physical activity might alleviate perceived fatigue symptoms after exercise in these individuals; however,...

Drafting is distinctive for team pursuit races in long-track speed skating. This study aims to compare the impact of drafting on physical intensity (heart rate [HR]) and perceived intensity (ratings of perceived exertion [RPE]) per drafting position. Eighteen skilled male (n = 9) and female (n = 9) skaters (20.0 ± 4.8 years) skated three trials, in...

Introduction: Wheelchair turning biomechanics is an under researched area despite its obvious relevance to functional mobility of wheelchair users. Wheelchair turns might be linked to a higher risk of upper limb injuries due to the increased forces and torques potentially associated with asymmetric movement. Our aim was to obtain a better theoreti...

Scientific interest in pacing goes back >100 years. Contemporary interest, both as a feature of athletic competition and as a window into understanding fatigue, goes back >30 years. Pacing represents the pattern of energy use designed to produce a competitive result while managing fatigue of different origins. Pacing has been studied both against t...

This study examined whether differentiated ratings of perceived exertion (RPE) (local; RPEL and central; RPEC) and overall RPE (RPEO) were different between exercise modes (upper- versus lower body) and/or changed after upper body training, providing relevant input for upper body exercise prescription/regulation. Eight rowers completed an increment...

Athletes use their own perception to monitor distance and regulate their pace during exercise, avoiding premature fatigue before the endpoint. On the other hand, they may also listen to music while training and exercising. Given the potential role of music as a distractor, we verified if music influenced the athletes' ability to monitor the distanc...

Purpose/Objective: This study aimed to (a) explore the associations between psychosocial factors and physical activity behavior in people with physical disabilities and/or chronic diseases, both between and within persons over time; and (b) examine whether these associations differ for people initiating and people maintaining physical activity beha...

Exploring pacing behaviour in people with intellectual disabilities (ID) in competition will help to better understand the impact of cognition and social environment in sports, providing support for the shaping of proper inclusive sports environments. The present experimental study aimed to (1) compare the pacing behaviour and performance between p...

Background: the goal-directed decision-making process of effort distribution (i.e. pacing) allows individuals to efficiently use energy resources as well as to manage the impact of fatigue on performance during exercise. Given the shared characteristics between pacing behaviour and other skilled behaviour, it was hypothesized that pacing behaviour...

As proposed by Triplett in 1898 and evidenced by a recent series of lab and field studies, racing against other competitors consistently results in increased performance compared to when racing alone. To explain this phenomenon, we will explore the process of self-regulation, a process relevant to pacing, which is linked to athletes’ emotions and f...

Purpose: To investigate differences in athletes' knowledge, beliefs, and training practices during COVID-19 lockdowns with reference to sport classification and sex. This work extends an initial descriptive evaluation focusing on athlete classification. Methods: Athletes (12,526; 66% male; 142 countries) completed an online survey (May-July 2020...

INTRODUCTION: Due to the low efficacy of the swimming movement and relatively high resistance of water, pacing is crucial for swimming performance [1]. Cross-sectional studies show that in the 200m freestyle event, adolescent swimmers tend to start too fast, as an even pacing behaviour has been proposed to yield the best performance and is preferre...

Different from the most popular thinking, the placebo effect is not a purely psychological phenomenon. A body of knowledge from multidisciplinary fields has shown that the expectation of a potential benefit when receiving a treatment induces a cascade of neurochemical-electrophysiological alterations in brain reward areas, including motor-related o...

Background Little is known of physical activity behaviour among adults with a disability and/or chronic disease during and up to 1 year post-rehabilitation. We aimed to explore (1) dose characteristics of physical activity behaviour among adults with physical disabilities and/or chronic diseases during that period, and (2) the effects of personal c...

This study aimed to analyse the reproducibility of mean power output during 20-min cycling time-trials, in a remote home-based setting, using the virtual-reality cycling software, Zwift. Forty-four cyclists (11 women, 33 men; 37 ± 8 years old, 180 ± 8 cm, 80.1 ± 13.2 kg) performed 3 x 20-min time-trials on Zwift, using their own setup. Intra-class...

In short-track speed skating, tactical positioning is essential for success as the race format (head-to-head) prioritises finishing position over finishing time. At present, our understanding of this phenomenon is based on measuring the similarity between athletes’ intermediate and final rankings. However, as this approach groups athlete performanc...

In short-track speed skating, tactical positioning is essential for success as the race format (head-to-head) prioritises finishing position over finishing time. At present, our understanding of this phenomenon is based on measuring the similarity between athletes’ intermediate and final rankings. However, as this approach groups athlete performanc...

The childhood obesity epidemic has persisted for over three decades, which has presented serious social, economic and health consequences worldwide. For researchers and policy makers alike, cycling has been a promising focus over recent years for developing long-term physically active lifestyles in urban environments, in addition to contributing to...

Objectives: Explore training-related knowledge, beliefs and practices of athletes and the influence of COVID-19-related lockdowns. Methods: Athletes [n = 12,526 classified: world-class (13%), international (21%), national (36%), state (24%), and recreational (6%)] completed an online survey (50 d; 17th May to 5th July 2020) exploring their trainin...

INTRODUCTION: The development of pacing behaviour (i.e. the outcome of the decision-making process regarding the distribution of effort over an exercise task) during adolescence has been established in literature [1]. However, the majority of the literature features only men and has a cross-sectional design, which is deficient in detecting developm...

The effect of an upper body resistance training program on maximal and submaximal handcycling performance in able-bodied males was explored. Eighteen able-bodied men were randomly assigned to a training group (TG: n=10) and a control group (CG: n=8). TG received 7 weeks of upper body resistance training (60% of 1 repetition maximum (1RM), 3×10 repe...

PURPOSE: Performance in running events, such as 1-Mile World Records (WR), depends both on having and effectively using energetic resources. Although often understood in terms of physiological capacity based on the Joyner model, the Critical Speed/D’ model is an alternative method of accounting for energetic capacity and use, based on prior perform...

The aim of this novel study was to analyse performance changes across qualifying heats, semifinals and finals in world-class sprinters and hurdlers. Finalists' finishing positions, times and rankings at the Olympic Games and IAAF World Championships (2012-2019) were obtained. 78% of gold, 67% of silver and 38% of bronze medallists won their qualify...

Objective To examine the association between self-reported activity pacing (a strategy to manage fatigue symptoms) and objectively-measured physical activity behaviours in adults with multiple sclerosis. Design Single cross-sectional study Setting Multiple sclerosis rehabilitation centre in Colchester, United Kingdom. Subjects Twenty-one adults...

Background: People with physical disabilities and/or chronic diseases report lower levels of physical activity and well-being than the general population, which potentially is exacerbated through the COVID-19 pandemic. This study explored the international literature on physical activity, sedentary behavior and well-being in adults with physical di...

For special populations such as people with a mental health issue or learning disability, a disconnect between the ability to accurately monitor and regulate exercise behaviour can lead to reduced levels of physical activity, which, in turn, is associated with additional physical or mental health problems. Activity pacing is a strategy used in clin...

Detrimental mental fatigue effects on exercise performance have been documented in constant workload and time trial exercises, but effects on a maximal incremental test (MIT) remain poorly investigated. Mental fatigue-reduced exercise performance is related to an increased effort sensation, likely due to a reduced prefrontal cortex (PFC) activation...

Less than 1% of all sports participants ever reach the top and become successful professional athletes. Defining expert performance is one of the greatest conundrums for sports professionals and it tends to be susceptible to subjective biases. Challenges in defining expertise especially arise with sports which, by nature, lack objective criteria fo...

The current study analysed the pacing behaviour of athletes competing in the middle‐long track event finals of the IAAF Under 18 and Under 20 World Championships between 2015 and 2018. Official finishing times, 1000‐m split times and positioning data of 116 female and 153 male athletes, competing in the middle‐long distance running (3000 m, 5000 m...

Background: Activity pacing is a behavioral strategy for coping with fatigue, optimizing physical activity (PA) levels, and achieving a paced approach to lifestyle and sustainable self-regulated exercise practice to optimize health and well-being. Yet little is known about how activity pacing affects PA and health-related quality of life (HRQOL) wh...

Pacing places a high demand on intellectual functioning and has been found useful for classification of athletes with intellectual impairments (II). This may also be true in open-loop sports like basketball. The current study aimed to investigate the pacing behaviour of basketball players with and without II. Using time-motion analysis, the activit...

This study evaluated the effect of a low-intensity norm duration synchronous handcycle wheelchair training in untrained able-bodied women. The training group (n = 9) received 7-weeks of low-intensity upper body training in an instrumented handcycle on a motor-driven treadmill (MDT), 3 × 30 min/week at 30% heart rate reserve. The control group (n =...

Purpose: To identify Health-related Quality of Life (HR-QoL) trajectories in a large heterogeneous cohort of people with a physical disability and/or chronic disease during and after rehabilitation and to determine which factors before discharge are associated with longitudinal trajectory membership. Methods: A total of 1100 people with a physic...

Tailored activity pacing could help manage fatigue and improve physical activity. However, little is known about how to tailor activity pacing for people with multiple sclerosis. This study aims to evaluate the effect of a tailored activity pacing intervention on fatigue and physical activity behaviours in adults with multiple sclerosis. Twenty-one...

The current study determined the test–retest reliability and concurrent validity of the Adapted Short QUestionnaire to ASsess Health-enhancing physical activity (Adapted-SQUASH) in adults with disabilities. Before filling in the Adapted-SQUASH twice with a recall period of 2 weeks, participants wore the Actiheart activity monitor up to 1 week. For...

An essential determinant for success in sports is pacing. Cognitive mechanisms like self-regulation and executive functions are strongly related to adequate pacing behaviour, and people with Intellectual Impairment (II) experience shortfalls in those skills. Previous literature in children without II revealed that pacing is at least partly dependen...

INTRODUCTION: Pacing is crucial for optimal performance in ultra-endurance events (1). This study investigated the impact of sex, category and athletes’ performance capacity on pacing and performance during the World 24-hour Mountain Bike Championships. METHODS: Data from 837 men and 157 women in 8 editions of the race (2012-2019) were analysed. At...

Purposes To identify fatigue trajectories during/after stroke rehabilitation, to determine characteristics associated with trajectory membership before discharge and to investigate how these trajectories and activity pacing are associated with sustained physical activity after rehabilitation. Methods People after stroke (n = 206) were followed fro...

Purpose: The behavior of an opponent has been shown to alter pacing and performance. To advance our understanding of the impact of perceptual stimuli such as an opponent on pacing and performance, this study examined the effect of a preexercise cycling protocol on exercise regulation with and without an opponent. Methods: Twelve trained cyclists...

Aim: In this narrative review the potential and importance of handcycling are evaluated. Four conceptual models form the framework for this review; (1) the International Classification of Functioning, Disability and Health; (2) the Stress-Strain-Capacity model; (3) the Human-Activity-Assistive Technology model; and (4) the power balance model for c...

The current study determined the test-retest reliability and concurrent validity of the Adapted Short QUestionnaire to ASsess Health-enhancing physical activity (Adapted-SQUASH) in adults with disabilities. Before filling in the Adapted-SQUASH twice with a recall period of two weeks, participants wore the Actiheart activity monitor up to one week....

Background: Monitoring and interfacing technologies may increase physical activity (PA) program adherence in older adults, but they should account for aspects influencing older adults' PA behavior. This study aimed at gathering preliminary wrist-based PA adherence data in free-living and relate these to the influencing factors. Methods: Ten heal...

Speed skating is a technical endurance sport. Still, little is known about technical changes in junior speed skaters. Therefore, changes in technique throughout a 1500-m time-trial of elite junior speed skaters is investigated to explore differences between sexes, performance levels and competitive seasons. At (inter)national 1500-m competitions, k...

Detrimental mental fatigue effects on exercise performance have been documented in constant workload and time trial exercises, but effects on a maximal incremental test (MIT) remain poorly investigated. Mental fatigue-reduced exercise performance is related to an increased effort sensation, likely due to a reduced prefrontal cortex (PFC) activation...

Fatigue is common in people with multiple sclerosis (MS). Activity pacing is a behavioral way to cope with fatigue and limited energy resources. However, little is known about how people with MS naturally pace activities to manage their fatigue and optimize daily activities. This study explored how activity pacing relates to fatigue and physical ac...

Purpose: To analyse the development of pacing behaviour of athletes during adolescence, using a longitudinal design. Methods: Lap times of male short-track speed skaters (140 skaters, 573 race performances) over two or more 1500-m races during Junior World Championships between 2010 and 2018, were analysed. Races were divided into four sections...

De manier waarop sporters tijdens een race of wedstrijd hun energie verdelen (ook wel pacing gedrag genoemd) kan het verschil maken tussen winnen en verliezen. Daarnaast is een afwijkende verdeling van energie over een langere termijn in relatie gebracht met een verhoogde kans op overtraining en blessures. De ontwikkeling van pacing gedrag start al...

Purpose: To examine the differences in muscle fatigability after resistance exercise performed with fast tempo (FT) compared with slow tempo (ST). Methods: A total of 8 resistance-trained males completed FT and ST hexagonal-barbell deadlifts, consisting of 8 sets of 6 repetitions at 60% 3-repetition maximum, using a randomized crossover design....

Regular exercise can improve wellbeing, yet data are scarce on how persons with disabling conditions may benefit from active lifestyles, due to the complexities of exercise prescription in this population. A novel medical concept for exercise prescription called activity pacing is the subject of this review, which identifies the potential for this...

Purpose: We analyzed the impact of sex, performance level and substantial speed reductions (SSR) on pacing in the Rio 24-h Marines Ultramarathon. This will provide insights into the importance of minimizing variations in speed in relation to optimal pacing in endurance events. Methods: Runners (30 males and 21 females), classified as high- (HP) and...

Purpose: This study aimed to evaluate the implementation of a physical activity counseling program in rehabilitation and to study heterogeneity in received counseling and investigate its association with changes in patients’ physical activity outcomes. Methods: This prospective cohort study was conducted in 18 rehabilitation institutions. Data were...

Previous research has shown enhanced performance and altered pacing behaviour in the presence of a virtual opponent during middle-distance cycling time trials with a duration of 2 min and longer. The purpose of this study was to determine whether these effects are also present in cycling time trials of shorter duration. Twelve physically active men...

Purpose: To investigate the placebo effect of caffeine on pacing strateg