The improvement in walking speed induced by resistance training is associated with increased muscular strength but not skeletal muscle mass in older women

Objective: The purpose of the present study was to analyze whether improvements in fast walking speed induced by resistance training (RT) are associated with changes in body composition, muscle quality, and muscular strength in older women. Methods: Twenty-three healthy older women (69.6?±?6.4 years, 64.95?±?12.9?kg, 1.55?±?0.07?m, 27.06?±?4.6?kg/m²) performed a RT program for 8 weeks consisting of 8 exercises for the whole body, 3 sets of 10–15 repetitions maximum, 3 times a week. Anthropometric, body composition (fat-free mass [FFM], skeletal muscle mass [SMM], legs lean soft tissue [LLST], fat mass), knee extension muscular strength (KE1RM), muscle quality index (MQI [KE1RM/LLST]), and 10-meter walking test (10-MWT) were performed before and after the intervention. Results: Significant (P?<?.05) changes were observed from pre- to post-training for FFM (+1.6%), MQI (+7.2%), SMM (+2.4%), LLST (+1.8%), KE1RM (+8.6%), fat mass (?1.4%), and time to perform 10-MWT (?3.7%). The percentage change in 10-MWT was significantly associated with percentage change in MQI (r?=??0.46, P?=?.04) and KE1RM (r?=??0.45, P?=?.04), however not associated percentage of changes in SMM (r?=?0.01, P?=?.97), LLST (r?=??0.22, P?=?.33), and body fat (r?=?0.10, P?=?.66). Conclusion: We conclude that the improvement in the 10-MWT after an 8-week RT program is associated with increases in lower limb muscular strength and muscle quality, but not with muscle mass or body fat changes in older women.     

Body composition in athletes: A comparison of densitometric methods and tracking of individual differences

Abstract

Measuring body composition in athletes can provide valuable information on training and nutritional status. The aim of this study was to compare percentage body fat (PF) obtained by hydrostatic weighing (HW) to PF via air-displacement plethysmography (ADP), and to evaluate tracking of individual differences between both methods over time in elite college athletes. Thirty-one male and 33 female athletes (18.0–36.4 years) were measured by ADP and HW. Twenty-one subjects (10 men, 11 women) were measured again 61±11 days later to evaluate consistency of individual differences between methods. Mean PF differed significantly in men (HW: 9.4±2.4%, ADP: 11.3±3.4%, P<0.05) but not in women (HW: 19.1±2.4%, ADP: 19.5±3.7%). A significant trend in mean bias was found in both genders between HW-ADP suggesting an underestimation of PF by ADP at lower mean PF and an overestimation of PF by ADP at higher mean PF. Up to 73% of variance in differences between methods at follow-up was explained by differences between methods at the first measurement occasion. Both densitometric methods cannot be used interchangeably when measuring and tracking the body composition of individual elite athletes using a 2-component model of body composition. Differences between methods appear to track within an individual. The individual-specific causes of these differences remain to be determined.     

Evaluation of body composition with bioimpedence. A comparison between athletic and non-athletic children

Purpose: Conventional Bioelectrical Impedance Analysis (BIA) or Bioelectrical Impedance Vector Analysis (BIVA) can provide direct evaluations of body composition. The purpose of this study was to evaluate lean and fat mass (FM), and hydration of children involved in daily competitive sports. Methods: 190 non-athletic [8.2–10.5 years] and 29 competitive children [8.0–10.5 years] were enrolled. They were evaluated: at baseline (t0), 6 months (t1) and one year (t2). Anthropometric, BIA and BIVA, lean and FM, and hydration evaluations were performed. Results: Resistance (R/h) and reactance (Xc/h) were lower at t0 in competitive individuals when compared to controls. Xc/h (+3.28) significantly increases in competitive when compared to non-competitive individuals (+0.66, p for difference: 0.011), while phase angle (PA) was lower at t0 (5.72 vs. 6.17, p?<?.001) and after 6 months (p?=?.001). Total body water adjusted for height (TBW/h) significantly increased only in non-athletes (+0.50?±?0.13, p?<?.001) between t0 and t1. At t1, extracellular water (ECW) significantly decreased (p?=?.026) in the two groups: ?0.45?±?0.19% in non-competitive, ?1.63?±?0.49% in competitive subjects, while intracellular water (ICW) increased. At one-year follow-up (t2), there were no statistically significant differences in R/h, Xc/h and PA in competitive individuals when compared to baseline and t1. Furthermore, we observed at t2 that hours/week of training, age, male gender and body mass index can influence FFM/h and FM/h in both competitive and non-competitive subjects. In particular, a direct correlation was for hours/week and FFM/h, inverse for hours/week and FM/h. Conclusions: Body mass index does not allow evaluating differences in lean body mass and FM between athletes and non-athletes. BIA and BIVA can give more reliable details about body composition differences in competitive adolescents and non-competitive, outlining a progressive decline in ECW and increase in ICW without affecting TBW composition of athletes.     

Bone mass in girls according to their BMI,VO2 max,hours and years of practice

The accumulation of bone mass during puberty is related with bone health in adulthood. This accumulation is influenced by diverse factors such as body mass index (BMI), maximal oxygen uptake (VO₂ max), hours of training and years of sport practice. For this reason, the objective of this study is to analyse the influence of these variables on bone mass in young female athletes. The sample is formed of 120 healthy girls with ages between 9 and 13 (11.32?±?1.6?years old), divided into two groups depending on their BMI, VO₂ max, hours of training and years of sport practice. The participants completed a series of tests to evaluate level of sexual development, body composition (fat mass, lean mass and bone mass) and physical condition. The results show higher values of total lean mass, total fat mass and percentage of body fat in the groups with higher BMI in prepubertal girls and pubertal girls (p?2 max, in the prepubertal group, girls with lower VO₂ max had higher values of total fat mass (p?p?2 max also showed a higher total fat mass (p?相似文献   

Nutritional intake and body composition changes in a UCI World Tour cycling team during the Tour of Spain

Abstract

The aim of this study was to quantify the food intake of an International Cyclist Union (UCI) World Tour professional cyclist team and to analyse changes in body composition during the Tour of Spain. Nine male professional road cyclists (31.3?±?3.0 years) volunteered to participate in the study. Nutritional data were collected each day throughout the 3-week Tour by two trained investigators who weighed the food ingested by the cyclists. Mean nutritional intake of the cyclists was as follows: carbohydrate, 12.5?±?1.8?g/kg/day of body weight (BW) (65.0?±?5.9%); fat, 1.5?±?0.5 g/kg/day BW (17.9?±?5.6%); and protein, 3.3?±?0.3?g/kg/day BW (17.1?±?1.6%). Intake of all micronutrients, except for folate, vitamin D and potassium (which were 78.7%, 46% and 84% of Recommended Dietary Allowances (RDA), respectively), exceeded the RDA. Height, weight, skinfolds, circumferences and diameters were taken following the guidelines outlined by the International Society for the Advancement of Kinanthropometry. Body density, body fat percentage, muscle mass, total muscle mass and fat mass of the arms and thighs were calculated. Percentage body fat, fat mass and upper arm fat mass significantly decreased (p < .05) after the Tour independent of the equation method used in the calculations. Total muscle mass remained unchanged. Generally, this sample of cyclists consumed more protein and less fat than the recommended amount and had low weight, BMI and fat mass. It is suggested that sports nutritionists design personalised diets in order to maintain a correct proportion of nutrients as well as controlling possible anthropometrical changes that could affect performance.     

Effect of two different intensity distribution training programmes on aerobic and body composition variables in ultra-endurance runners

The aim of this study was to compare the effects of two different intensity distribution training programmes (polarized (POL) and threshold (THR)) on aerobic performance, strength and body composition variables in ultra-endurance runners. Twenty recreationally trained athletes were allocated to POL (n?=?11; age: 40.6?±?9.7 years; height: 175.4?±?7?cm; weight: 73.5?±?10.8?kg; fat mass 18.4?±?6.0%; VO₂max: 55.8?±?4.9?ml/kg/min) or THR group (n?=?9; age: 36.8?±?9.2 years; height: 178.5?±?4.2?cm; weight: 75.5?±?10.4?kg; fat mass 14.9?±?5.3%; VO₂max: 57.1?±?5.2?ml/kg/min) and performed the 12 weeks training programme. Both programmes had similar total time and load but a different intensity distribution (POL?=?79.8?±?2.1% in Zone 1; 3.9?±?1.9% in Zone 2; 16.4?±?1.5% in Zone 3; THR?=?67.2?±?4.6% in Zone 1; 33.8?±?4.6% in Zone 2; 0% in Zone 3). Body composition, isokinetic strength and aerobic running performance were measured before and after each programme. Both groups decreased fat mass after training (POL= Δ–11.2%; p?=?.017; ES?=?0.32; THR= Δ–18.8%; p?p?=?0.003; ES?=?0.71) and 12?km/h (Δ–4.5%; p?=?.026; ES?=?0.73) and running time to exhaustion (Δ2.4%; p?=?.011; ES?=?0.33). No changes were observed in strength and no significant differences were observed between the group in any variable. Compared with THR distribution, 12 weeks of POL training efficiently improves aerobic performance in recreational ultra-endurance runners.     

Validity of “Generalized” Equations for Body Composition Analysis in Women Athletes

Abstract

Equations by Jackson, Pollock, and Ward (1980) and by Durnin and Womersly (1974) for estimating body density (BD) from skinfolds (SF) purportedly overcome the criticism of “population specificity” by taking into account age and the curvilinear relationship between SFs and BD. Selected equations were validated on 79 women athletes against %fat and fat(kg) measured by underwater weighing. Equations by Sloan, Burt, and Blyth (1962), Wilmore and Behnke (1970), and Katch and McArdle (1973) were also evaluated to compare the newer equations to older ones. The mean estimate of %fat by one equation by Jackson et al. utilizing the sum of triceps, abdomen, suprailiac and thigh SF was the same as the true value (20.1%) and correlated .795 (SEE ± 3.27 total error 3.23). Regression analysis showed it to have acceptable accuracy over the range of sample values (10.3–34.0%). The Durnin-Womersly equations overestimated %fat by 3.9 to 4.4% and were not acceptable. For the older equations, the mean Sloan et al. estimate (20.8 %Fat) was not significantly different from the true value and correlated .779 (SEE ± 3.37 total error 3.47). Regression analysis showed it to overestimate fat in leaner subjects and to underestimate it in fatter ones, making it unacceptable. The Wilmore-Behnke equation overestimated %fat by 4.3%. Equations by Jackson et al., using the sum of triceps, suprailiac and thigh skinfolds, and by Katch and McArdle were shown to be acceptable if the ordinate values were adjusted (1.0994921 to 1.1074921 and 1.08347 to 1.09147 respectively) to account for the higher density of women athletes.     

Assessment of subcutaneous adipose tissue using ultrasound in highly trained junior rowers

Introduction: There is a large variety of body fat (BF) measurements, which differ in validity and reliability. The aim of this study was to measure subcutaneous adipose tissue (SAT) using ultrasound (US) in highly trained junior rowers in a field setting, establish fat patterning profiles, and compare the profiles between male and female athletes. Skinfold thickness (SKF) measurements were also taken and compared to US measurements. Methods: Sixteen athletes participated. US measurements were taken at eight sites and reported as a sum of SAT (D): D_Excl (without embedded structures) and D_Incl (including embedded structures). SKF was measured at three sites and reported as a sum of adipose tissue thickness (SUM_SKF). Results: Mean SAT thickness (D_Incl) was 27.6?±?12.4?mm for males and 65.5?±?11.8?mm for females. Females had significantly more embedded structures than males (P?=?.016). Significant correlations were found (P?<?.001, r?=?0.92) comparing SUM_SKF to D_Incl and between SKF and US measurements at the thigh site (P?<?.001, r?=?0.86). Conclusion: US is a suitable tool to measure BF in the field testing of athletes and enables measurements of SAT with an accuracy and reliability not reached before. The sum of thicknesses (D_Incl or D_Excl) can be used to represent subcutaneous fat based on accurate measurements of uncompressed SAT thicknesses.     

Effects of a 15-week accumulated brisk walking programme on the body composition of primary school children

Abstract

The purpose of this study was to establish whether an accumulated brisk walking programme, performed during the school day, is effective in changing body composition in primary school children aged 5–11 years. Altogether, 152 participants (79 boys and 73 girls) took part in this repeated-measures intervention study, divided into groups of walkers and controls. The walkers took part in the intervention during school time, which involved brisk walking around the school grounds for 15 min in the morning and afternoon, at least three times a week for 15 weeks. This represented an additional 90 min of moderate physical activity per week. The controls undertook their usual school day activities. Pre- and post-intervention anthropometric and body composition measures were taken. Body fat (?1.95 ± 2.6%) and fat mass (?0.49 ± 1.0 kg) were significantly reduced in the walkers after the intervention, whereas the controls showed no significant changes in these measures. Our results show that regular accumulated bouts of brisk walking during the school day can positively affect body composition in primary school children.     

Body composition and inflammatory markers in pubertal girls: Comparison between athletes and non-athletic controls

Various inflammation parameters are increased with childhood obesity, but few comparable data are found in lean growing athletes. This study aims to characterize differences in 12 simultaneously measured inflammatory parameters between pubertal rhythmic gymnasts (RG) and untrained controls (UC), and to examine the relationship between body composition and inflammatory markers. Sixty 10–12-year-old girls were divided into RG (n?=?30) and UC (n?=?30). Fat mass (FM) and fat free mass (FFM) were measured by dual-energy X-ray absorptiometry. Leptin and 12 inflammatory parameters (interleukin [IL]-2, IL-4, IL-6, IL-8, IL-10, vascular endothelial growth factor, interferon-gamma [IFN-γ], tumor necrosis factor-alpha, IL-1α, IL-1β, monocyte chemotactic protein-1 and epidermal growth factor) were measured from fasting blood samples. No differences were seen in 12 inflammatory markers between studied groups. As expected, leptin (RG: 2.4?±?1.1; UC: 7.6?±?4.2?ng?ml^?1) and FM (RG: 7.3?±?2.3; UC: 11.8?±?5.1?kg) were lower (p?<?.05) in RG compared to UC. In the whole group of lean pubertal girls, 69.0% of the variability in body FM was determined by leptin, and 11.2% of the variability in body FFM was explained by IFN-γ. In conclusion, measured 12 inflammatory biomarkers were not different between RG and UC, despite lower leptin and FM in RG. In lean pubertal girls, IFN-γ was independently associated with FFM, and leptin with FM.     

Body Composition Comparison: Bioelectric Impedance Analysis with Dual-Energy X-Ray Absorptiometry in Adult Athletes

The primary purpose of this study was to investigate the accuracy of the DF50 (ImpediMed Ltd, Eight Mile Plains, Queensland, Australia) bioelectrical impedance analysis device using dual-energy x-ray absorptiometry as the criterion in two groups: endurance athletes and power athletes. The secondary purpose was to develop accurate body fat percentage prediction equations for each group based on bioelectrical impedance analysis data and/or the combination of bioelectrical impedance analysis and anthropometric data.

Eighty male athletes (40 elite endurance athletes and 40 were power athletes), age 19–48 with body mass indexes ranging from 18.9 to 37.4 were recruited. Anthropometric measurements were taken. Body composition was assessed by dual-energy x-ray absorptiometry and bioelectrical impedance analysis. An athlete-specific bioelectrical impedance analysis prediction equation was developed by stepwise regression analysis using dual-energy x-ray absorptiometry as the criterion and bioelectrical impedance analysis data and anthropometric measurements as predictor variables.

The DF50 bioelectrical impedance analysis significantly overestimated body fat percentage by 6.4 ± 0.5 in the entire group (p < .001) and in both the endurance group (6.1 ± .6, p < .001) and the power group (6.7 ± 0.7, p < .001). The endurance and power group showed no significant difference in the error of estimation by bioelectrical impedance analysis (p = .554), indicating that bioelectrical impedance analysis has the same error in both groups. The final prediction equation incorporated both anthropometric variables as well as bioelectrical impedance analysis variables and produced an adjusted r² of .982 and a standard error of the estimate (SEE) of 1.98 for the entire group. This prediction equation used bioelectrical impedance analysis measurements and anthropometric measurements, specifically trunk measurements, to account for trunk size, a common source of error in bioelectrical impedance analysis equations. Follow-up validation studies are necessary to further validate the equations produced.     

Energy expenditure in professional flat jockeys using doubly labelled water during the racing season: Implications for body weight management

To formulate individualized dietary strategies for jockeys, it is vital that energy requirements are quantified. We measured total energy expenditure (TEE) over two separate weeks in spring and summer using doubly labelled water in a group of male flat jockeys (n?=?8, 36.9?±?5.7 years, 164?±?8?cm, 54.6?±?2.5?kg). Total energy intake (TEI) was self-recorded, as were all riding and structured exercise activity. Mean daily TEE was 10.83 (±2.3) and 10.66 (±1.76) MJ, (p?=?.61) respectively. Self-reported TEI were 6.03 (±1.7) and 5.37 (±1.1) MJ (p?=?.40), respectively, and were significantly lower than TEE (p?=?.01). Mean race rides were 17 (±6) and 13 (±3; p?=?0.37) and horses ridden at morning exercise were 8 (±6) and 7 (±4; p?=?.77) respectively. Additional structured exercise was 76.25 (±95.1) and 52.5 (±80.9) min per week (p?=?.35), respectively. At the individual level, TEE was related to body mass and the level of non-racing physical activity, but not riding. Physical activity levels for TEE were 1.76 (±0.37) and 1.69 (±0.27; p?=?.59) and appear modest when compared with other athletes, and similar to age-matched non-athletes, suggesting that conventional sport-specific nutritional recommendations do not appear applicable. The large discrepancy between TEE and TEI suggests significant under reporting of dietary intake. These data now provide an appropriate framework from which to formulate jockey nutritional guidelines to promote the ability to achieve the daily weight target and improve athlete welfare.     

The effect of body composition and BMI on 25(OH)D response in vitamin D-supplemented athletes

Fat mass is inversely associated with vitamin D status, and athletes with the most adipose tissue may have the greatest risk for insufficient (25(OH)D 20–32?ng?mL^?1) or deficient (25(OH)D??1) status. The effects of fat and lean mass on 25(OH)D change in response to vitamin D supplementation have yet to be elucidated in athletes. In addition, vitamin D has a known role in bone health yet a link between short-term changes in 25(OH)D and bone turnover in indoor athletes have not yet been described. Thirty-two collegiate swimmers and divers (19 male, 13 female; 19 (1) years) participated in a 6-month randomized controlled trial and consumed either 4000?IU?d^?1 of vitamin D₃ (n?=?19) or placebo (PLA; n?=?13). Anthropometry and blood collection of 25(OH)D, bone-specific alkaline phosphatase (B-ALP) and N-terminal telopeptide (NTx) occurred at three time points. Dual-energy X-ray absorptiometry measured body composition analysis at baseline and endpoint. In the vitamin D group, BMI was negatively correlated with 6-month 25(OH)D change (R?=??0.496; P?=?.03) and a stronger predictor of 25(OH)D change (P?=?.04) than ultraviolet B exposure and fat mass change. Athletes in the high bone turnover group showed significantly greater losses of 25(OH)D over 6-months compared to athletes in the low bone turnover group (P?=?.03). These results suggest athletes within the normal BMI category experience a diminished response to 4000?IU?d^?1 of vitamin D₃ supplementation, and periods of high bone turnover may be an additional risk factor for developing compromised vitamin D status in athletes.     

Sedentary behaviour and adiposity in elite athletes

Abstract

Overweight and obesity are defined as abnormal or excessive fat accumulation that presents a health risk. Even in athletes an increased adiposity affects health and performance. Sedentary behaviour has been associated with higher levels of adiposity, independent of moderate-to-vigorous physical activity. However, it is unclear whether this independent relationship still exists in highly trained athletes. The aim of this study was to examine the association of sedentary behaviour with body fatness in elite athletes. Cross-sectional data from 82 male athletes (mean age 22 years) were used. Total and regional body composition was measured by dual energy X-ray absorptiometry. Self-reported time spent in sedentary behaviour and weekly training time was assessed in all participants at one time point and multiple regression analyses were used. Sedentary behaviour predicted total fat mass (β = 0.77; 95% CI: 0.36–1.19, P < 0.001) and trunk fat mass (β = 0.25; 95% CI: 0.07–0.43, P = 0.007), independent of age, weekly training time, and residual mass (calculated as weight-dependent variable) but not abdominal fat. Also, no associations of sedentary behaviour with fat-free mass, appendicular lean soft tissue, and body mass index were found. These findings indicate that athletes with higher amounts of sedentary behaviour presented higher levels of total and trunk fatness, regardless of age, weekly training time, and residual mass. Therefore, even high moderate-to-vigorous physical activity levels do not mitigate the associations between sedentary behaviour and body fatness in highly trained athletes.     

Male professional tennis players maintain constant serve speed and accuracy over long matches on grass courts

The potential effect of fatigue on stroke production in tennis players is still controversial. The aim of this study was to analyse the tennis serve speed and accuracy in prolonged male professional matches played on grass courts. We analysed tennis serve statistics from five-set Wimbledon matches (n?=?15; 30 players). Results showed that match duration averaged 208.3?±?28.3?min. The overall serve speed was 177.0?±?10.2?km/h in the first set and 176.1?±?11.7?km/h in the fifth set (p?=?.34). The difference of all accuracy values of first set serves was not significantly different from those of the fifth set: percentage of valid first serves, 63.1?±?11.1% vs. 62.3?±?11.8%, respectively (p?=?.78); percentage of “aces”, 11.2?±?9.1% vs. 10.0?±?8.9%, respectively (p?=?.39); percentage of “winners”, 2.6?±?7.6% vs. 1.2?±?2.2%, respectively (p?=?.36); percentage of “double faults”, 2.8?±?3.0% vs. 2.8?±?3.4% (p?=?.97). In conclusion, tennis players were able to maintain constant serve speed and accuracy over five-set matches played on grass courts. Professional tennis players are capable of overcoming fatigue and/or make movement adjustments to effectively perform complex technical strokes like the serve throughout matches played on grass courts lasting more than 3?h in average.     

Effect of repeat-sprint training in hypoxia on post-exercise interleukin-6 and F2-isoprostanes

This investigation examined the oxidative stress (F₂-Isoprostane; F₂-IsoP) and inflammatory (interleukin-6; IL-6) responses to repeat-sprint training in hypoxia (RSH). Ten trained male team sport athletes performed 3(sets)*9(repetitions)*5?s cycling sprints in simulated altitude (3000?m) and sea-level conditions. Mean and peak sprint power output (MPO and PPO) were recorded, and blood samples were collected pre-exercise, and again at 8 and 60?min post-exercise. Both MPO and PPO were significantly reduced in hypoxia (compared to sea-level) in the second (MPO: 855?±?89 vs. 739?±?95?W, p?=?.006; PPO: 1024?±?114 vs. 895?±?112?W, p?=?.010) and third (MPO: 819?±?105 vs. 686?±?83?W, p?=?.008; PPO: 985?±?125 vs. 834?±?99?W, p?=?.008) sets, respectively. IL-6 was significantly increased from pre- to 1?h post-exercise in both hypoxia (0.7?±?0.2 vs. 2.4?±?1.4?pg/mL, p?=?.004) and sea-level conditions (0.7?±?0.2 vs. 1.6?±?0.3?pg/mL, p?d?=?0.80) suggesting higher IL-6 levels of post-hypoxia. F₂-IsoP was significantly lower 1?h post-exercise in both the hypoxic (p?=?.005) and sea-level (p?=?.002) conditions, with no differences between trials. While hypoxia can impact on exercise intensity and may result in greater post-exercise inflammation, it appears to have little effect on oxidative stress. These results indicate that team sport organisations with ready access to hypoxic training facilities could confidently administer RSH without significantly increasing the post-exercise inflammatory or oxidative stress response.     

Intraseason changes in the body composition of collegiate female gymnasts

Body composition measures were collected pre‐, mid‐ and post‐season on a team of eight national‐calibre collegiate women gymnasts to examine intraseason changes. Also analysed were interseason changes using pre‐ and post‐season data on five of the eight subjects during the current and previous year, according to a 2 x 2 (years x tests) analysis of variance repeated‐measures design. Skinfold, circumference and diameter measures were collected with percentage body fat, lean body mass and body density determined by regression equations developed specifically for collegiate female gymnasts.

Intraseason body weight decreased significantly from pre‐ to mid‐season (x = 55.0 and 53.6 kg respectively); but the difference between mid‐ and post‐season (53.9 kg) values was not significant (P>0.05). The majority of the 1.4 kg weight loss occurred during intense pre‐season conditioning and not during the actual season. Percentage body fat, on the other hand, decreased significantly from pre‐to mid‐season and mid‐ to post‐season (x = 21.4%, 17.4% and 13.45% respectively; P<0.0005). Body density increased significantly from pre‐ to mid‐season and mid‐ to post‐season (x = 1.0476, 1.0584 and 1.0681 respectively; P<0.0005). Of the circumference and skinfold values used in calculating percentage body fat and body density, only the skinfold values displayed significant decreases throughout the season.

Interseason analyses revealed no significant changes in any of the dependent measures between seasons, despite consistent trends. There were no significant years x tests interactions and all intraseason changes for two seasons (n = 5) were the same as those found in more detailed analysis of a single season (n = 8) except in the case of weight loss, which was marginally significant (P < 0.046) in the single‐season and not in the dual‐season analysis (P>0.05).

Body composition of these gymnasts changed in many ways within competitive seasons. The most pronounced changes observed were decreases in subcutaneous fat and increases in body density. This study reinforces the need for administrators, coaches and athletes to be concerned with percentage body fat and skinfold measures rather than weight alone when determining if a person is ‘fat’.     

Growth and body composition in Brazilian female rhythmic gymnastics athletes

Abstract

The aim was to analyse the physical growth and body composition of rhythmic gymnastics athletes relative to their level of somatic maturation. This was a cross-sectional study of 136 athletes on 23 teams from Brazil. Mass, standing height and sitting height were measured. Fat-free and fat masses, body fat percentages and ages of the predicted peak height velocity (PHV) were calculated. The z scores for mass were negative during all ages according to both WHO and Brazilian references, and that for standing height were also negative for all ages according to WHO reference but only until 12 years old according to Brazilian reference. The mean age of the predicted PHV was 12.1 years. The mean mass, standing and sitting heights, body fat percentage, fat-free mass and fat mass increased significantly until 4 to 5 years after the age of the PHV. Menarche was reached in only 26% of these athletes and mean age was 13.2 years. The mass was below the national reference standards, and the standing height was below only for the international reference, but they also had late recovery of mass and standing height during puberty. In conclusion, these athletes had a potential to gain mass and standing height several years after PHV, indicating late maturation.     

Low energy availability and low body fat of female gymnasts before an international competition

Abstract

The purpose of the present study was to evaluate dietary intake and body composition of elite rhythmic gymnastics (RG) athletes prior to a competition event. Sixty-seven rhythmic gymnasts (18.7 ± 2.9 years old) of high performance level, with 36.6 ± 7.6 h of training/week were evaluated in order to collect training and competition data, medical and gynaecological history, detailed dietary intake and body composition before an international competition. The majority of the participants (n = 40; 59.7%) had already menstruated, but age of menarche was delayed (15.3 ± 1.3 years) and all revealed menstrual irregularities. Gymnasts' body mass (48.4 ± 4.9 kg) and body mass index (BMI; 17.4 ± 1.1 kg/m²) were below the normal for age, and height (1.66 ± 0.05 m) was normal or even slightly above normal for age. Body fat was 9.0 ± 2.0% with no significant differences between age strata. Gymnasts exhibited low energy availability (EA; 31.5 ± 11.9 kcal/kg fat-free mass (FFM)/day). The average carbohydrate and protein intakes were 5.1 ± 2.3 g/kg/day and 1.6 ± 04 g/kg/day, which correspond to 51.4 ± 7.2% and 16.9 ± 3.4% of total energy intakes, respectively; average fat contribution was 33.0 ± 5.3%. Low intakes of pantothenic acid, folate and vitamins D, E and K and of minerals, including calcium, iron and magnesium were reported. Intakes of thiamine, riboflavin, niacin, vitamins A, B-6, B-12, C and manganese and zinc were above-adequate (P < 0.05). Low EA, low body fat and micronutrient deficiencies are common among RG.