89 research outputs found
THE PSYCHOLOGICAL AND PHYSIOLOGICAL EFFECTS OF MAKING WEIGHT IN INTERNATIONAL LEVEL TAEKWONDO ATHLETES
International standard Taekwondo athletes are unique, given they are required to compete in two differing weight categories for both World (WT) and Olympic (OG) events, which have some of the largest differences amongst other making weight combat sports. Typically, this demographic will lose body mass (BM) via acute and chronic methods, in order to make the lower limit of a category. Despite a raft of literature examining the frequency, magnitude, occurrence and influences of these practices, the motivations to engage in this convention are still largely unknown. Additionally, few studies have investigated this population for both body composition and activity energy expenditures (AEE), utilising either criterion or field based measurement tools during periods of BM loss and as such, these athletes may be susceptible to low energy availability (LEA) leading to relative energy deficiency in sport (RED-S). Therefore, the main aim of this thesis was to examine the psychological and physiological health and performance consequences of making weight in international standard Taekwondo athletes. Study 1 examined the frequency, magnitude, occurrence and influences of BM loss and making weight practices, in a cohort of 106 male and female Cadet, Junior and Senior Taekwondo athletes, directly after a weigh in at a major national championships. In agreement with previous research, there were no differences between sexes, however, for the first time this study highlighted key disparities in the frequency, magnitude and occurrence of BM loss and making weight practices between age groups. Additionally for the first time, the magnitudes between WT and OG weight category requirements were elucidated, showing relative BM losses which are far higher than previously characterised in this demographic. This study also highlighted the key stakeholder groups influencing the engagement in these practices, which in younger age groups was shown to be predominantly parents. Finally, it was conveyed that the nutritional and ergogenic dietary supplement knowledge of this group was largely poor when compared to optimal guidelines. In Study 2, semi structured interviews were conducted with the key stakeholder groups (5 athletes, 5 coaches, 5 parents), as identified in Study 1. Again, high magnitudes of BM loss were described by all stakeholders in agreement with Study 1. Furthermore, each stakeholder group described their perceptions of the making weight process, with all expressing it can negatively affect health and performance, but was necessary to enhance advantages in competition. The nutritional and ergogenic dietary supplement knowledge of all stakeholder groups was poor as described in Study 1. All stakeholders agreed that education, targeted particularly at the coaches, alongside improvements in national and global federation making weight policies, were required to improve current practice. Study 3 investigated the requirements of BM losses between the OG and WT categories in 18 international standard Taekwondo athletes, within 4 days prior to a competition weigh in. This emphasised the need to engage in extreme making weight practices in order to meet elected OG category allowances, as described in Studies 1 and 2. Additionally, the body composition of these athletes was examined utilising both dual x-ray absorptiometry (DXA) and various sum of skinfold (ΣSKf) fat mass percentage (FM%) equations. For the first time, this study highlighted body compositional differences between athletes of varying weight categories, where all of the cohort had low FM% (13% loss of BM for competition. Utilising the findings and methods of Studies 3 and 4, energy availability (EA) was examined and measures were taken throughout to examine the potential for RED-S consequences on both health and performance parameters. The athlete successfully achieved their elected weight category limit, with minimal negative associations of RED-S syndromes exhibited on markers of metabolic, endocrine, cardiovascular, bone turnover and psychological functions. Additionally there were no negative effects apparent on either tested maximal dynamic strength/power and cardiorespiratory conditioning or competitive performances. However, post competition there was a significant rebound hyperphagic response, congruent with BM overshoot and despite the success of the intervention, this should be given further consideration in the future. This thesis serves as a means to improve the making weight practices of international standard Taekwondo athletes, by affording the ability to examine both body composition and AEE in the field, whilst providing a safe and effective intervention to lose BM without the negative associations of RED-S. However, despite this, the findings of this thesis also serve as a call to action to the national and global governing federations, in enhancing the education of key stakeholders in this sport, whilst considering the addition of more weight categories to reduce the incidence of extreme and dangerous making weight practices throughout older age divisions
Determining concentric and eccentric force–velocity profiles during squatting.
The force–velocity relationship of muscular contraction has been extensively studied. However, previous research has focussed either on isolated muscle or single-joint movements, whereas human movement consists of multi-joint movements (e.g. squatting). Therefore, the purpose of this study was to investigate the force–velocity relationship of isovelocity squatting. Fifteen male participants (24±2 years, 79.8±9.1 kg, 177.5±6 cm) performed isovelocity squats on a novel motorised isovelocity device (Kineo Training System) at three concentric (0.25, 0.5, and 0.75 m s−1) and three eccentric velocities (−0.25, −0.5, and −0.75 m s−1). Peak vertical ground reaction forces, that occurred during the isovelocity phase, were collected using dual force plates (2000 Hz) (Kistler, Switzerland). The group mean squat force–velocity profile conformed to the typical in vivo profile, with peak vertical ground reaction forces during eccentric squatting being 9.5 ± 19% greater than isometric (P = 0.037), and occurring between −0.5 and −0.75 m s−1. However, large inter-participant variability was identified (0.84–1.62 × isometric force), with some participants being unable to produce eccentric forces greater than isometric. Sub-group analyses could not identify differences between individuals who could/could not produce eccentric forces above isometric, although those who could not tended to be taller. These finding suggest that variability exists between participants in the ability to generate maximum eccentric forces during squatting, and the magnitude of eccentric increase above isometric cannot be predicted solely based on a concentric assessment. Therefore, an assessment of eccentric capabilities may be required prior to prescribing eccentric-specific resistance training
Case Study: Extreme Weight Making Causes Relative Energy Deficiency, Dehydration and Acute Kidney Injury in a Male Mixed Martial Arts Athlete.
The aim of the present case study was to quantify the physiological and metabolic impact of extreme weight cutting by an elite male MMA athlete. Throughout an 8-week period, we obtained regular assessments of body composition, resting metabolic rate (RMR), VO2peak and blood clinical chemistry to assess endocrine status, lipid profiles, hydration and kidney function. The athlete adhered to a "phased" weight loss plan consisting of 7 weeks of reduced energy (ranging from 1300 - 1900 kcal.d-1) intake (phase 1), 5 days of water loading with 8 L per day for 4 days followed by 250 ml on day 5 (phase 2), 20 h fasting and dehydration (phase 3) and 32 h of rehydration and refuelling prior to competition (phase 4). Body mass declined by 18.1 % (80.2 to 65.7 kg) corresponding to changes of 4.4, 2.8 and 7.3 kg in phase 1, 2 and 3, respectively. We observed clear indices of relative energy deficiency, as evidenced by reduced RMR (-331 kcal), inability to complete performance tests, alterations to endocrine hormones (testosterone: 6 mmol.L-1). Moreover, severe dehydration (reducing body mass by 9.3%) in the final 24 hours prior to weigh-in induced hypernatremia (plasma sodium: 148 mmol.L-1) and acute kidney injury (serum creatinine: 177 μmol.L-1). These data therefore support publicised reports of the harmful (and potentially fatal) effects of extreme weight cutting in MMA athletes and represent a call for action to governing bodies to safeguard the welfare of MMA athletes
Nutritional Considerations for Female Athletes in Weight Category Sports
Weight making can be described as the process of reducing body mass in events where aesthetics, propulsion or the requirement to meet a specific weight category limit, are considered to be of competitive importance. Cross sectional research specifically focussed on weight category sports, has highlighted behaviours and practices that are similar in athletes of both sexes. Regardless of this and despite parallel participation in weight category sporting events, females are drastically underrepresented in studies examining body mass loss interventions across both chronic and acute timeframes. However, it has been well characterised that these types of body mass loss strategies can be causative of low energy availability, leading to consequences of female athlete triad and relative energy deficiency in sports. Furthermore, female-specific body composition and physiological systems modulated by the anterior pituitary and ovarian hormones within the menstrual cycle or use of hormonal contraception, can lead to potential outcomes which need to be considered carefully, particularly when employing acute weight loss strategies that are often utilised by weight making athletes. Therefore, the aim of this article serves to review the aforementioned issues, whilst offering practical recommendations via initial assessment, chronic/acute interventions and refeeding/recovery plans to help support the implementation of body mass loss strategies in the context of weight making specifically with female athletes
“Horrible—But Worth It”: Exploring Weight Cutting Practices, Eating Behaviors, and Experiences of Competitive Female Taekwon-Do Athletes. A Mixed Methods Study
This mixed methods study aimed to investigate weight cutting practices of female taekwon-do athletes internationally and explore their experiences of “making weight.” A survey of weight loss practices and eating behaviors was completed by 103 taekwon-do athletes from 12 countries, which illustrated that 72.5% of athletes engage in both acute and chronic weight loss practices prior to competition and that there were higher levels of disordered eating within this athletic population than nonweight cutting athletes. Semistructured interviews were conducted with five international-level competitors; thematic analysis of the interviews identified that the women in general felt weight cutting was “horrible—but worth it” and the women believed that (a) weight cutting is unpleasant, difficult, and challenging; and (b) weight cutting provides a competitive advantage. The implications of this study are that weight cutting is widespread among high-level competitive female taekwon-do athletes and this is unlikely to change given the perceived advantages. Efforts are needed to make sure that the women are knowledgeable of the risks and are provided with safe and effective means of making weight
Perceptions of Current Issues in Female Sport Nutrition From Elite Athletes, Practitioners, and Researchers
In response to the ongoing sex data gap, the present study provides a qualitative exploration of females’ nutritional experiences in elite sporting environments. Semistructured interviews were conducted with multiple participant groups (n = 18), including athletes (n = 7), practitioners (n = 6), and researchers (n = 5) across differing disciplines within professional sporting organiza-tions and/or national governing bodies. Combined content and thematic analysis provided an insight into the specific factors influencing current sport nutrition practices. A common theme highlighted among all participant groups was the paradoxical struggle between adequate fueling for training and competition demands, and the fear this may impact body mass and body composition goals. This tension was identified as being rooted within athletes’ perceptions of body image and driven by other participant groups and wider societal ideals. Each participant group also highlighted influences on cravings and approaches to food and dietary supplementation, centered around individual perceptions and challenges driven by symptomology associated with the female menstrual cycle and contraceptive use. To address these challenges, all participant groups called for more research to inform future change and continuing education pathways. In summary, this study contributes to providing a more complete understanding of elite female athlete sport nutrition experiences than currently exists. Multiple perspectives highlight the complexity of providing sport nutrition support to elite female athlete populations and directs future research, and practice, to reconsider one-size-fits-all approaches and acknowledge unique individual contexts which may influence these areas
Perceptions of Current Issues in Female Sport Nutrition From Elite Athletes, Practitioners, and Researchers
In response to the ongoing sex data gap, the present study provides a qualitative exploration of females’ nutritional experiences in elite sporting environments. Semistructured interviews were conducted with multiple participant groups (n = 18), including athletes (n = 7), practitioners (n = 6), and researchers (n = 5) across differing disciplines within professional sporting organiza-tions and/or national governing bodies. Combined content and thematic analysis provided an insight into the specific factors influencing current sport nutrition practices. A common theme highlighted among all participant groups was the paradoxical struggle between adequate fueling for training and competition demands, and the fear this may impact body mass and body composition goals. This tension was identified as being rooted within athletes’ perceptions of body image and driven by other participant groups and wider societal ideals. Each participant group also highlighted influences on cravings and approaches to food and dietary supplementation, centered around individual perceptions and challenges driven by symptomology associated with the female menstrual cycle and contraceptive use. To address these challenges, all participant groups called for more research to inform future change and continuing education pathways. In summary, this study contributes to providing a more complete understanding of elite female athlete sport nutrition experiences than currently exists. Multiple perspectives highlight the complexity of providing sport nutrition support to elite female athlete populations and directs future research, and practice, to reconsider one-size-fits-all approaches and acknowledge unique individual contexts which may influence these areas
Current practices in weight making sport
All combat and a number of non-combat sports follow differing degrees of weight categorisation (see Table 1) and there are also a number of aesthetically judged sports where it is considered advantageous to have the lowest fat mass possible, including gymnastics, body building, bikini modelling, etc. The rationale for weight categorisation is to promote fairer competition between competitors of equal size/body mass and stature/height (Langan-Evans et al., 2011). However, many weight categorised athletes lose large amounts of body mass to gain a competitive advantage in either height, limb length or power to mass ratio. Several studies have shown these athletes employ short duration or ‘rapid weight loss’ (RWL) techniques, whereas others maintain low energy availability over prolonged periods of time. As such, a recent article has called for RWL to be banned (Artioli et al., 2016) and others have highlighted the dangers of consistently reduced energy availability (Mountjoy et al., 2014). This article highlights some of the body mass loss practices employed by athletes across a range of sports and demonstrate the impact that this has on psychophysiological health
Under-Fuelling for the Work Required? Assessment of Dietary Practices and Physical Loading of Adolescent Female Soccer Players during an Intensive International Training and Game Schedule
Previous studies demonstrate that “under-fuelling” (i.e., reduced carbohydrate (CHO) and energy intake (EI) in relation to recommended guidelines) is prevalent within adult female soccer players, the consequence of which may have acute performance and chronic health implications. However, the dietary practices of adolescent female soccer players, a population who may be particularly at risk for the negative aspects of low energy availability (LEA), are not well documented. Accordingly, we aimed to quantify EI and CHO intake, physical loading and estimated energy availability (EA) in elite national team adolescent female soccer players (n = twenty-three; age, 17.9 ± 0.5 years) during a 10-day training and game schedule comprising two match days on day six (MDa) and nine (MDb). The players self-reported their EI via the remote food photography method, whilst the physical loading and associated exercise energy expenditure were assessed via GPS technology. The relative CHO intake was significantly greater (all p 6 g·kg−1) for intensive training and game schedules. These data provide further evidence for the requirement to create and deliver targeted player and stakeholder education and behaviour change interventions (especially for younger athletes) that aim to promote increased daily CHO intake in female soccer players
A 5-Year Analysis of Weight Cycling Practices in a Male World Champion Professional Boxer: Potential Implications for Obesity and Cardiometabolic Disease
Weight cycling is thought to increase the risk of obesity and cardiometabolic disease in nonathletic and athletic populations. However, the magnitude and frequency of weight cycling is not well characterized in elite athletes. To this end, we quantified the weight cycling practices of a male World Champion professional boxer competing at super middleweight (76.2 kg). Over a 5-year period comprising 11 contests, we assessed changes in body mass (n = 8 contests) and body composition (n = 6 contests) during the training camp preceding each contest. Time taken to make weight was 11 ± 4 weeks (range: 4–16). Absolute and relative weight loss for each contest was 12.4 ± 2.1 kg (range: 9.8–17.0) and 13.9% ± 2.0% (range: 11.3–18.2), respectively. Notably, the athlete commenced each training camp with progressive increases in fat mass (i.e., 12.5 and 16.1 kg for Contests 1 and 11) and reductions in fat-free mass (i.e., 69.8 and 67.5 kg for Contests 1 and 11, respectively). Data suggest that weight cycling may lead to “fat overshooting” and further weight gain in later life. Larger scale studies are now required to characterize the weight cycling practices of elite athletes and robustly assess future cardiometabolic disease risk. From an ethical perspective, practitioners should be aware of the potential health consequences associated with weight cycling
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