Effect of Two Different Weight-Loss Rates on Body Composition and Strength and Power-Related Performance in Elite Athletes
Abstract and Figures
When weight loss (WL) is necessary, athletes are advised to accomplish it gradually, at a rate of 0.5-1 kg/wk. However, it is possible that losing 0.5 kg/wk is better than 1 kg/wk in terms of preserving lean body mass (LBM) and performance. The aim of this study was to compare changes in body composition, strength, and power during a weekly body-weight (BW) loss of 0.7% slow reduction (SR) vs. 1.4% fast reduction (FR). We hypothesized that the faster WL regimen would result in more detrimental effects on both LBM and strength-related performance. Twenty-four athletes were randomized to SR (n = 13, 24 ± 3 yr, 71.9 ± 12.7 kg) or FR (n = 11, 22 ± 5 yr, 74.8 ± 11.7 kg). They followed energy-restricted diets promoting the predetermined weekly WL. All athletes included 4 resistance-training sessions/wk in their usual training regimen. The mean times spent in intervention for SR and FR were 8.5 ± 2.2 and 5.3 ± 0.9 wk, respectively (p < .001). BW, body composition (DEXA), 1-repetition-maximum (1RM) tests, 40-m sprint, and countermovement jump were measured before and after intervention. Energy intake was reduced by 19% ± 2% and 30% ± 4% in SR and FR, respectively (p = .003). BW and fat mass decreased in both SR and FR by 5.6% ± 0.8% and 5.5% ± 0.7% (0.7% ± 0.8% vs. 1.0% ± 0.4%/wk) and 31% ± 3% and 21 ± 4%, respectively. LBM increased in SR by 2.1% ± 0.4% (p < .001), whereas it was unchanged in FR (-0.2% ± 0.7%), with significant differences between groups (p < .01). In conclusion, data from this study suggest that athletes who want to gain LBM and increase 1RM strength during a WL period combined with strength training should aim for a weekly BW loss of 0.7%.
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... Food intake is an important factor related to body weight variations 4 . In addition to caloric restriction, macronutrient manipulation is a strategy being extensively studied [5][6][7][8][9] . In this context, low-carbohydrate (L-CHO) diets are highlighted as being interesting for weight loss and cardiovascular risk 1 . ...
... On the other hand, Mansoor et al. 15 observed that despite the greater weight loss obtained with the L-CHO diet and the increase in HDL-c, there was a concomitant increase in LDL-c. Severe restrictions can lead to unwanted effects 5,6,16,17 , and it is necessary to identify effective and safe restriction levels, including when associated with physical training. ...
... Adopting an adequate diet in conjunction with exercise leads to promoting a negative energy balance, which stimulates the mobilization of energy reserves and promotes weight loss 6 . Exercise enhances the muscle glucose uptake potential through insulin-and noninsulin-dependent pathways, as well as promotes fatty acid oxidation capacity through an This study has some limitations to consider when interpreting the results. ...
Introdução: O excesso de peso corporal e suas comorbidades representam um grave problema de saúde pública. Intervenções pautadas em dieta associada a prática de exercício físico têm se mostrado úteis para a perda de peso e melhora da saúde global da população, incluindo a saúde cardiovascular. Objetivo: Avaliar o efeito de 12 semanas de dieta hipocalórica com restrição de carboidrato (CHO) associada ao Treinamento Funcional de Alta Intensidade (HIFT) na saúde cardiometabólica de adultos com sobrepeso. Métodos: Trata-se de um ensaio clínico randomizado. Participaram 31 adultos com sobrepeso, divididos em dois grupos com base na intervenção dietética: CHO reduzido (R-CHO, ≤130g/dia; n=15) e CHO adequado (A-CHO, >130 g/dia; n=16). O risco cardiometabólico foi avaliado utilizando os parâmetros lipêmico, insulinêmico e glicêmico. Para avaliar os efeitos da intervenção foi aplicado ANOVA-two-way com post-hoc de Bonferroni, sendo considerado estatisticamente significativo valores de p<0,05. Resultados: Após 12 semanas de intervenção observou-se redução na concentração de LDL-c, VLDL-c, colesterol total e triacilglicerol, e do número de fatores de risco para doenças metabólicas, independente do grupo, e aumento do HDL-c, porém o resultado da análise intragrupo demonstrou que o aumento significativo do HDL-c foi observado apenas para o grupo A-CHO. Conclusão: As duas intervenções dietéticas se mostraram efetivas em promover a redução do risco cardiometabólico. No entanto, melhoras na concentração do HDL-c e na classificação final do risco cardiometabólico indicaram que a adequação do CHO da dieta parece ser uma melhor estratégia associada a restrição calórica e a prática de HIFT.
... A possible explanation for this sexrelated discrepancy is the somewhat more rapid weight loss experienced by the male athletes. Evidence indicates that a slower rate of weight loss is conducive to maintaining lean mass [24,25]. However, the absolute amount of weekly weight loss experienced by the male athletes (−0.42 kg/week) was consistent with that shown to preserve lean mass in elite athletes [25], calling into question whether the rate of loss was an explanatory factor. ...
... Evidence indicates that a slower rate of weight loss is conducive to maintaining lean mass [24,25]. However, the absolute amount of weekly weight loss experienced by the male athletes (−0.42 kg/week) was consistent with that shown to preserve lean mass in elite athletes [25], calling into question whether the rate of loss was an explanatory factor. It should be noted that the athletes in the aforementioned intervention [25] were not physique athletes and had a mean post-study BF level of 15.5%. ...
... However, the absolute amount of weekly weight loss experienced by the male athletes (−0.42 kg/week) was consistent with that shown to preserve lean mass in elite athletes [25], calling into question whether the rate of loss was an explanatory factor. It should be noted that the athletes in the aforementioned intervention [25] were not physique athletes and had a mean post-study BF level of 15.5%. Accordingly, an alternative explanation could be that female athletes had higher amounts of fat mass at the end of contest preparation compared with males, with almost all displaying double-digit %BF levels immediately prior to competition. ...
The present paper aimed to systematically review case studies on physique athletes to evaluate longitudinal changes in measures of body composition, neuromuscular performance, chronic hormonal levels, physiological adaptations, and psychometric outcomes during pre-contest preparation. We included studies that (1) were classified as case studies involving physique athletes during the pre-contest phase of their competitive cycle; (2) involved adults (18+ years of age) as participants; (3) were published in an English-language peer-reviewed journal; (4) had a pre-contest duration of at least 3 months; (5) reported changes across contest preparation relating to measures of body composition (fat mass, lean mass, and bone mineral density), neuromuscular performance (strength and power), chronic hormonal levels (testosterone, estrogen, cortisol, leptin, and ghrelin), physiological adaptations (maximal aerobic capacity, resting energy expenditure, heart rate, blood pressure, menstrual function, and sleep quality), and/or psychometric outcomes (mood states and food desire). Our review ultimately included 11 case studies comprising 15 ostensibly drug-free athletes (male = 8, female = 7) who competed in various physique-oriented divisions including bodybuilding, figure, and bikini. The results indicated marked alterations across the array of analyzed outcomes, sometimes with high inter-individual variability and divergent sex-specific responses. The complexities and implications of these findings are discussed herein.
... While the influence of energy deficiency on some physiological and endocrine parameters, including bone metabolism and reproductive hormones, are well-characterised, evidence on the direct effect of energy deficiency on human physical capacity and athletic performance is scarce and limited . Available evidence suggests that even when facing energy deficit or showing signs of chronic energy deficiency, exercising individuals are able to maintain and increase physical capacity, or achieve levels of athletic performance compatible with international-level competition (Areta, 2020;Fudge et al., 2006;Garthe et al., 2011b;Garthe et al., 2011a;Hulmi et al., 2017;Langan-Evans et al., 2021;Stellingwerff, 2018;Tornberg et al., 2017;Zachwieja et al., 2001). ...
... Improvements in physical capacity have been reported with concomitant energy deficit and weight-loss in active and trained individuals (Fogelholm et al., 1993;Louis et al., 2020;Zachwieja et al., 2001), and elite athlete populations (Garthe et al., 2011a;Langan-Evans et al., 2021). Energy deficiency concomitant with top-level competitive performances has been documented, for example, in elite long-distance runners prior to their main competitions (Fudge et al., 2006), in an Olympic middle-distance female (Stellingwerff, 2018), in an elite worldclass female cyclist (Areta, 2020), and in race walkers (Burke et al., 2023). ...
Energy deficiency profoundly disrupts normal endocrinology, metabolism, and physiology, resulting in an orchestrated response for energy preservation. As such, despite energy deficit is typically thought as positive for weight-loss and treatment of cardiometabolic diseases during the current obesity pandemic, in the context of contemporary sports and exercise nutrition, chronic energy deficiency is associated to negative health and athletic performance consequences. However, the evidence of energy deficit negatively affecting physical capacity and sports performance is unclear. While severe energy deficiency can negatively affect physical capacity, humans can also improve aerobic fitness and strength while facing significant energy deficit. Many athletes, also, compete at an elite and world-class level despite showing clear signs of energy deficiency. Maintenance of high physical capacity despite the suppression of energetically demanding physiological traits seems paradoxical when an evolutionary viewpoint is not considered. Humans have evolved facing intermittent periods of food scarcity in their natural habitat and are able to thrive in it. In the current perspective it is argued that when facing limited energy availability, maintenance of locomotion and physical capacity are of high priority given that they are essential for food procurement for survival in the habitat where humans evolved. When energetic resources are limited, energy may be allocated to tasks essential for survival (e.g. locomotion) while minimising energy allocation to traits that are not (e.g. growth and reproduction). The current perspective provides a model of energy allocation during energy scarcity supported by observation of physiological and metabolic responses that are congruent with this paradigm.
... Examples of such dietary strategies successfully employed by athletes include restricting energy intake by increasing protein suppl, and introducing intermittent fasting -a time-restricted diet during which food intake is limited to a few hours per day. Another form of dietary restriction that has become popular among athletes is a diet very low in carbohydrates -the ketogenic diet [4][5][6][7][8]. ...
... With professional guidance by a qualified athlete health and performance team (eg, sports medicine, sports dietitians and sports physiologists), manipulating body composition in a safe and controlled manner might enhance performance, social recognition and acceptance. 28 However, without qualified, professional supervision with strict policies on consent and data sharing, the improved performance results are often short-lived, and with prolonged exposure to problematic LEA can lead to the development of REDs, DE behaviours or EDs. 8 This is of concern, in particular for youth athletes, due to the potentially negative physical and psychological outcomes, as the time period of adolescence is high-risk for the development of BD and EDs. 7 29 Therefore, measuring body composition for performance purposes is not recommend under the age of Box 1 Continued always caused by the independent variable and influences the dependent variable. ...
Overall athlete health is a stated priority by the International Olympic Committee (IOC), yet it can be difficult for athletes to safely balance nutritional needs, training load, recovery, social interactions, expectations and other demands. The effect of energy intake and, especially, low energy availability (LEA) on athlete mental health, is understudied. In this narrative review, we examine research that has included psychological factors and mental health variables when investigating the effect of LEA, dieting/restrictive eating and Relative Energy Deficiency in Sport (REDs), since the 2018 IOC consensus statement on REDs. Based on currently available data, early psychological indicators associated with problematic LEA are mood changes, fatigue and psychological conflict. More severe mental health outcomes associated with REDs are reduced well-being, elevated anxiety, depressive symptoms and eating disorders. We propose a psychological model that helps structure how possible risk factors (eg, body dissatisfaction, environmental demands or increased training load) and moderating (eg, gender, sport) and/or potential mediating (eg, social climate, self-esteem) factors are associated with LEA and ultimately REDs. The current scientific literature underscores the importance of including mental health factors when screening for REDs and for developing a clinical approach to address the psychological sequelae of REDs once diagnosed. An interdisciplinary perspective is recommended. Lastly, and importantly, the athlete perspective urges clinicians to not underestimate the drive for success and denial of health consequences that athletes demonstrate when pursuing their sport goals.
... The weight of the men, totally undressed at almost, was measured using a scale Salter England (Model 235-6S), pressing a tenth that defect; it was regularly calibrated; the scale needle being reset had a new weigh-in. Based on height and weight, the body mass index (BMI) was calculated from the ratio [P (kg)] / [T (m)] 2. Subsequently, the percentage of body fat (PCTG) was determined using the thicknesses of 4 skin folds found at the biceps, triceps, subscapular and iliac crest, in accordance with the PCTG estimation method [14]. For this, a constant pressure adipometer (caliber: 10g/mm2). ...
The objective of our study was to assess the body composition of the active populations of the hinterland in relation to the activity practiced. This study involved 513 subjects stratified by age and male sex, divided into three activities, namely: hunting, agriculture and fishing, subjects followed the following measures: It appears that significant differences were noted between fishermen, hunters and farmers for a similar age group. For example, fishermen aged 30-39 years showed significant superiority in weight, muscle mass, body volume and body water. Finally, the evolution of interest parameter values from 30 to 60 years was increasing for the percentage of fat mass (PCTG) and the total amount of subcutaneous fat (GSHQ). On the other hand, it was decreasing for data from other variables. Revenue-generating activities depend on physical capacity.
Introduction
The release of luteinising hormone (LH) before ovulation is disrupted during a state of low energy availability (EA). However, it remains unknown whether a threshold EA exists in athletic populations to trigger ovulatory disturbances (anovulation and luteal phase deficiency) as indicated by peak/mid-luteal serum progesterone concentration (Pk-PRG) during the menstrual cycle.
Methods
We assessed EA and Pk-PRG in 15 menstrual cycles to investigate the relationship between EA and Pk-PRG in free-living, competitive (trained-elite) Guatemalan racewalkers ( n = 8) and runners ( n = 7) [aged: 20 (14–41) years; post-menarche: 5 (2–26) years; height: 1.53 ± 0.09 m; mass: 49 ± 6 kg (41 ± 5 kg fat-free mass “FFM”)]. EA was estimated over 7 consecutive days within the follicular phase using food, training, and physical activity diaries. A fasted blood sample was collected during the Pk-PRG period, 6–8 days after the LH peak, but before the final 2 days of each cycle. Serum progesterone concentration was quantified using electrochemiluminescence immunoassay.
Results
Participants that reported an EA of <35 kcal·kg FFM ⁻¹ ·day ⁻¹ ( n = 7) exhibited ovulatory disturbances (Pk-PRG ≤9.40 ng·mL ⁻¹ ). Athletes with EA ≥36 kcal·kg FFM ⁻¹ ·day ⁻¹ ( n = 8) recorded “normal”/“potentially fertile” cycles (Pk-PRG >9.40 ng·mL ⁻¹ ), except for a single racewalker with the lowest reported protein intake (1.1 g·kg body mass ⁻¹ ·day ⁻¹ ). EA was positively associated with Pk-PRG [ r (9) = 0.79, 95% confidence interval (CI): 0.37–0.94; p = 0.003; 1 − β = 0.99] after excluding participants ( n = 4) that likely under-reported/reduced their dietary intake.
Conclusions
The result from the linear regression analysis suggests that an EA ≥ 36 kcal·kg FFM ⁻¹ ·day ⁻¹ is required to achieve “normal ovulation.” The threshold EA associated with ovulatory disturbances in athletes and non-invasive means of monitoring the ovulatory status warrant further research.
Purpose:
We investigated short-term (9 d) exposure to low energy availability (LEA) in elite endurance athletes during a block of intensified training on self-reported well-being, body composition and performance.
Methods:
Twenty-three highly trained race walkers undertook a ~ 3 w research-embedded training camp during which they undertook baseline testing and 6 d of high energy/carbohydrate (CHO) availability (40 kcal·kg FFM-1·d-1) before being allocated to 9 d continuation of this diet (HCHO: n = 10 M, 2F) or a significant decrease in energy availability to 15 kcal·kg FFM-1·d-1 (LEA: n = 10 M, 1F). A real-world 10,000 m race walking event was undertaken before (Baseline) and after (Adaptation) these phases, with races being preceded by standardized CHO fueling (8 g·kg BM-1 for 24 h and 2 g·kg BM-1 pre-race meal).
Results:
DXA-assessed body composition showed BM loss (2.0 kg; p < 0.001), primarily due to a 1.6 kg fat mass reduction (p < 0.001) in LEA, with smaller losses (BM: 0.9 kg; p = 0.008; fat mass: 0.9 kg; p < 0.001) in HCHO. The Recovery-Stress Questionnaire for Athletes (RESTQ-76), undertaken at the end of each dietary phase showed significant Diet*Trial effects for Overall Stress (p = 0.021), Overall Recovery (p = 0.024), Sport-Specific Stress (p = 0.003) and Sport-Specific Recovery (p = 0.012). However, improvements in race performance were similar: 4.5 ± 4.1% and 3.5 ± 1.8% for HCHO and LEA, respectively (p < 0.001). The relationship between changes in performance and pre-race BM was not significant (r = -0.08 [-0.49, 0.35]; p = 0.717).
Conclusions:
A series of strategically timed but brief phases of substantially restricted energy availability might achieve ideal race weight as part of a long-term periodization of physique by high performance athletes, but the relationship between BM, training quality and performance in weight-dependent endurance sports is complicated.
The EDI-2 manual is currently out of print but the attached file provides the table of contents for the EDI-3 which includes all of the EDI-2 items as well as the updated scale structure and scoring system for the EDI-3
Aims:
To examine the effects of rapid weight loss on mood and performance among amateur boxers.
Methods:
Participants were 16 experienced amateur boxers. In stage 1, structured interviews were used to assess the type of strategies that boxers used to reduce weight and the value of performing at their desired weight in terms of performance. In stage 2, boxers completed a 4 x 2 minute (1 minute recovery) circuit training session. Boxers completed the circuit training session on three different occasions with a week between each. The first test was used to familiarise the boxers with the circuit training task; the second and third tasks were at their training weight and championship weight, respectively. Participants were given one week to reduce their body weight to their championship weight using their preferred weight making strategies; boxers reduced their body weight by an average of 5.16% of body weight.
Results:
Boxers typically lost weight by restricting fluid and food intake in the week leading to competition. Repeated measures multivariate analysis of variance results indicated that rapid weight loss among boxers was associated with poor performance, increased anger, fatigue, and tension, and reduced vigour.
Conclusions:
Strategies used to make weight by boxers are associated with poor performance and a negative mood profile.
The aim of the present study was to examine the effects of a combination of gradual and rapid body mass loss on the physical performance and psychological state of elite judo athletes. Participants were divided into two groups: the experimental (diet) group needed to reduce body mass by 2-6%, whereas the control group did not need to lose body mass. Body mass, percentage of body fat, vertical jump, repetitions of judo movements, rowing with additional loads, and the Profile of Mood States were assessed at 4 weeks before a championship and again one day before the same championship. Compared with 4 weeks before the championship, the experimental group showed a significant decrease in body mass (-4 +/- 1.1%, P < 0.05), estimated body fat (-10 +/- 4.0%, P < 0.05), and judo movement repetitions over 30 s (-4.5 +/- 2.7, P < 0.05), and an increase in scores for confusion (-14.6 +/- 7.9, P < 0.05) and tension (-10.1 +/- 12.5, P < 0.05), but a decrease in vigour (11.3 +/- 8.5, P < 0.05), one day before the championship. There was no difference in squat jump or countermovement jump performance or in judo movement repetitions over 5 s. Our results show that for the experimental group some aspects of performance were impaired one day before a competition, but performance of judo movements over 5 s was not affected.
The diet-induced thermogenesis of 12 healthy males of normal body weight was measured by means of indirect calorimetry over 6 h after test meals of 1, 2 or 4 MJ protein (white egg, gelatin, casein), carbohydrate (starch, hydrolyzed starch) or fat (sunflower oil, butter). The totals of the thermic responses proved to be dependent on the type of nutrient supplied as much as on its quantity. The effect of 1 MJ protein was at least three times as large as that of an isocaloric carbohydrate supply. The investigated dietary fats produced no evident thermic response. The doubling of the energy intake of either casein or hydrolyzed starch led to the approximate doubling of the thermic effect.
The purpose of this study was to examine the physiological effects of a weight-loss dietary regimen with or without exercise.
Thirty-five overweight men were matched and randomly placed into either a control group (C; N = 6) or one of three dietary groups; a diet-only group (D; N = 8), a diet group that performed aerobic exercise three times per week (DE; N = 11); and a diet group that performed both aerobic and strength training three times per week (DES; N = 10).
After 12 wk, D, DE, and DES demonstrated a similar and significant (P < or = 0.05) reduction in body mass (-9.64, -8.99, and -9.90 kg, respectively) with fat mass comprising 69, 78, and 97% of the total loss in body mass, respectively. The diet-only group also demonstrated a significant reduction in fat-free mass. Maximum strength, as determined by 1-RM testing in the bench press and squat exercise was significantly increased for DES in both the bench press (+19.6%) and squat exercise (+32.6%). Absolute peak O2 consumption was significantly elevated in DE (+24.8%) and DES (+15.4%). There were no differences in performance during a 30-s Wingate test for the DE and DES, whereas D demonstrated a significant decline in peak and mean power output. Resting metabolic rate (RMR) (kcal x d(-1)) was not significantly different for any of the groups except for the DE group. There were no significant changes in basal concentrations of serum glucose, BUN, cortisol, testosterone, and high density lipoprotein (HDL) cholesterol for any of the groups. Serum total cholesterol and low density lipoprotein (LDL) cholesterol were significantly decreased for all dietary groups. Serum triglycerides were significantly reduced for D and DES at week 6 and remained lower at week 12 for D, while triglycerides returned to baseline values for DES.
These data indicate that a weight-loss dietary regimen in conjunction with aerobic and resistance exercise prevents the normal decline in fat-free mass and muscular power and augments body composition, maximal strength, and maximum oxygen consumption compared with weight-loss induced by diet alone.
Athletes engage in a number of dietary and weight control practices which may influence metabolism, health, and performance. This paper reviews the literature on these factors with special emphasis on athletes who show large, frequent, and rapid fluctuations in weight (wrestlers) and athletes who maintain low weight and low percent body fat (e.g., distance runners, gymnasts, and figure skaters). A theory is presented which relates these weight patterns and the accompanying dietary habits to changes in body composition, metabolism, metabolic activity of adipose tissue, and the distribution of body fat. Changes in these physiological variables may be manifested in enhanced food efficiency (weight as a function of caloric intake) as the body seeks to protect and replenish its energy stores. This may explain the surprisingly low caloric intakes of some athletes. The health status of the athlete is a concern in this regard because there may be changes in fat distribution, risk factors for cardiovascular disease, and hormonal factors associated with reproductive functioning in both females and males. Amenorrhea in female athletes may be mediated at least in part by regional fat distribution; depletion of femoral fat depots (lactational energy reserves) may be the stimulus for cessation or disruption of menses.
Athletes reduce bodyweight for several reasons: to compete in a lower weight class; to improve aesthetic appearance; or to increase physical performance. Rapid bodyweight reduction (dehydration in 12 to 96 hours), typically with fluid restriction and increased exercise, is used by athletes competing in weight-class events. Gradual bodyweight reduction (over >1 week) is usually achieved by cutting energy intake to 75 to 130 kJ/kg/day. An intake of 100 kJ/kg/day results in a weekly bodyweight loss of roughly 1kg. Aerobic endurance capacity decreases after rapid bodyweight reduction, but might increase after gradual bodyweight reduction. Maximal oxygen uptake (V̇O2max) measured as L/min is unchanged or decreased after bodyweight loss, but V̇O2max measured as ml/kg/min may increase after gradual bodyweight reduction. Anaerobic performance and muscle strength are typically decreased after rapid bodyweight reduction with or without 1 to 3 hours rehydration. When tested after 5 to 24 hours of rehydration, performance is maintained at euhydrated levels. A high carbohydrate diet during bodyweight loss may help in maintaining performance. Anaerobic performance is not affected and strength can increase after gradual bodyweight reduction. Reductions in plasma volume, muscle glycogen content and the buffer capacity of the blood explain decreased performance after rapid bodyweight reduction. During gradual bodyweight loss, slow glycogen resynthesis after training, loss of muscle protein and stress fractures (caused by endocrinological disorders) may affect performance. Athletes’ bodyweight goals should be individualised rather than by comparing with other athletes. If the time between weigh-in and competition is
Six successful members of the British Women's Lightweight Rowing Team were assessed before and after two-month (1990) and four-month (1991) periods of weight-reduction controlled by reduced caloric intake, while engaged in their normal physical training. Fat free mass (FFM) was calculated from body weight (BW) by utilising total body potassium measurements. Maximal oxygen intake (VO2max), respiratory anaerobic threshold (Tvent), upper body anaerobic peak power (PP) and mean power (MP) outputs, and knee flexor (KF) and extensor (KE) isokinetic peak torques were among the physiological parameters assessed. No statistical differences were noted between the data obtained prior to the two weight-reduction periods, and both periods resulted in lower BW (p < 0.001) and FFM (p < 0.05); approximately 50% of the lost BW was FFM. At the end of the two-month weight-reduction period Tvent (p < 0.02) and KF (p < 0.02) decreased. In contrast, a similar BW loss during the four-month period was associated with higher VO2max (p < 0.01) and PP (p < 0.05) compared with values prior to weight reduction. Comparisons between the percentage changes pre to post BW loss showed that the longer weight-reduction period was associated with significantly improved VO2max (p < 0.01), Tvent (p < 0.005), PP (p < 0.05) and KF (p < 0.05). We conclude: a) the proportion (50%) of weight lost as FFM in the present elite rowers is higher than the suggested optimal figure of 22%, and b) compared to four months, 6-7% of BW loss over two months may adversely influence fitness-related parameters in international lightweight oarswomen.
This study examined risk factors and triggers for eating disorders in female athletes. Subjects included were all of the elite female athletes in Norway (N = 603), ages 12-35 yr, representing six groups of sports: technical, endurance, aesthetic, weight dependent, ball games, and power sports. The Eating Disorder Inventory was used to classify individuals at risk for eating disorders. Of the 117 athletes defined at risk, 103 were administered a structured clinical interview for eating disorders. A comparison group was also interviewed, consisting of 30 athletes chosen at random from a pool not at risk and matched to the at-risk subjects on age, community of residence, and sport. Ninety-two of the at-risk athletes met criteria for anorexia nervosa, bulimia nervosa, or anorexia athletica. The prevalence of eating disorders was higher in sports emphasizing leanness or a specific weight than in sports where these are less important. Compared with controls, eating disordered athletes began both sports-specific training and dieting earlier, and felt that puberty occurred too early for optimal performance. Trigger factors associated with the onset of eating disorders were prolonged periods of dieting, frequent weight fluctuations, a sudden increase in training volume, and traumatic events such as injury or loss of a coach.
In most situations involving a significant change in body weight, both fat-free body mass (FFM) and body fat participate, but the relative contribution of FFM and fat to the total weight change is influenced by the initial body fat content. Overfeeding: In experiments of at least 3-weeks' duration, the weight gain of thin people comprises 60-70% lean tissues, whereas in the obese it is 30-40%. Underfeeding: In humans, there is an inverse curvilinear relationship between initial body fat content and the proportion of weight loss consisting of lean tissue. The same trend holds for animals and birds, including loss during hibernation. Another factor is the magnitude of the energy deficit: as energy intake is reduced, lean tissue makes up an increasing fraction of the total weight loss. Exercise: If individuals lose much weight with exercise, the result is usually some loss of lean tissue as well as fat, and once again the proportion of lean loss to total weight loss is greater in thin people than in those who have larger body fat burdens. Members of twin pairs often differ in weight. In thin individuals, lean accounts for about half of the intrapair weight difference, whereas in the obese it accounts for only one quarter. Body fat content must be taken into account in evaluating body composition changes induced by nutrition and exercise.