Lower Fat Mass Percentage Research Articles

Are young female athletes at risk of amenorrhoea? analysis of body composition, nutritional and endocrine factors

BackgroundSpecific type and amount of high intensity training in athletes especially beginning before puberty, reduced body weight and lower percentage of fat mass have been put forward as potential factors...

HIV-Positive Patients With Nonalcoholic Fatty Liver Disease Have a Lower Body Mass Index and Are More Physically Active Than HIV-Negative Patients

To determine whether the clinical and metabolic features associated with nonalcoholic fatty liver disease (NAFLD) are similar between HIV-positive and HIV-negative male subjects. Twenty-six HIV-positive and 25 HIV-negative subjects with liver biopsy-proven NAFLD were compared for liver histology (extent of steatosis, steatosis grading, and fibrosis staging), blood biochemistry (glucose, insulin, C-peptide, hemoglobin A1c, and lipid profile), insulin resistance (IR) using a homeostasis model assessment, anthropometry (body mass index [BMI], waist circumference, and arm muscle area), dietary intake, and physical activity. The 2 groups were similar for age, liver histology, and IR. HIV-positive patients had a lower BMI (26.3 +/- 0.5 vs. 30.2 +/- 1.0 kg/m; P = 0.001) and lower percentage of fat mass (19.4 +/- 0.9 vs. 22.7 +/- 1.2; P = 0.026) when compared with HIV-negative patients. Although caloric intake was similar between groups, HIV-positive patients had a higher physical activity level (8.3 +/- 1.6 vs. 4.1 +/- 0.8 units of exercise per day; P = 0.029). Blood triglycerides were significantly higher (3.14 +/- 0.39 vs. 1.86 +/- 0.20 mmol/L; P = 0.006) in HIV-positive patients. Although NAFLD was similar between the 2 groups, HIV-positive patients had a lower BMI and were more physically active compared with HIV-negative patients. This may suggest that in HIV, NAFLD is associated with factors other than those related to body fatness, such as HIV infection and treatment.

Anthropometric features and body composition of young athletes practicing karate at a high and medium competitive level.

The aim of the study was to examine the anthropometric features and body composition of athletes practising karate at a high and medium competitive level. Our study was carried out on a sample of 35 subjects practising karate and aged from 16.0 to 32.5 years. This sample was divided into two groups: group 1 ( n=14 elite athletes) and group 2 ( n=21 amateur athletes). Various anthropometric measurements were taken (weight, height both standing and sitting, diameters, circumferences and skinfold thickness) from which different anthropometric indices were calculated (body mass index, Scelic and Grant indices, arm muscle circumference and area), and the somatotype was then determined. The body composition of each subject was assessed using the skinfold technique and the Jackson-Pollock (J-P) and Sloan-Weir (S-W) equations. The two groups of athletes showed very similar measurements regarding anthropometric characteristics. Only the Scelix index presented a significantly different value in the two groups (49.6+/-1.3 for group 1 vs. 51.1+/-1.3 for group 2; p<0.01). Group 1 showed a mesomorphic-ectomorphic somatotype, while the amateur athletes presented a balanced mesomorphic type. Moreover, a lower percentage of fat mass was more frequent in the first group (J-P=8.1+/-2.4%; S-W=8.9+/-3.3%) than in the second one (J-P=9.8+/-1.6%; S-W=11.2+/-3.7%), although the differences between the two groups were not significant. We conclude that group 1 is characterized by a slightly prominent vertical development of the skeletal frame. This could be an anthropometric characteristic that is best suited to meet the specific functional requirements of this sport. Moreover, both groups of athletes are characterized by a low percentage of fat mass, particularly the elite group.

Effects of chronic intensive training on androgenic and cortisol profiles in premenarchal female gymnasts.

The effect of intensive exercise training on urinary androgen and cortisol excretions in prepubertal girls of various ages was tested in competitive premenarchal gymnasts ( n=56) and in age-matched controls ( n=53). Both sexual maturation and bone age were assessed. Urinary excretions of androstenedione, dehydroepiandrosterone sulphate (DHEA-S), testosterone and cortisol were determined by radioimmunoassay procedures. The gymnasts were taller [mean (SD) 138.3 (9.0) cm vs 144.7 (8.3) cm; P<0.001] and lighter [32.0 (6.9) kg vs 36.7 (8.2) kg; P<0.001], and had a lower percentage of fat mass [16.8 (2.2)% vs 22.5 (6.6)%; P<0.0001] than the controls. There was no difference between groups in urinary testosterone, cortisol and DHEA-S levels, while androstenedione levels were significantly lower in gymnasts than in controls [mean (SEM) 187.10 (18.00) nmol/24 h vs 256.50 (15.00) nmol/24 h; P<0.01). There was no difference in the regression slopes between the two groups for all hormonal values. In conclusion, these results suggest that during the prepubertal period, intensive training alters only urinary androstenedione concentrations in girls.

Determinants of physical activity and physical and sports activities in French school children.

The influence of morphological, biological, sociological, psychological, and environmental factors on the practice of organized sports and the amount of moderate to vigorous physical activity was examined through a questionnaire and continuous heart-rate monitoring, for 80 schoolchildren, 11 to 16 years old. Sport-practicing boys had a lower percentage of fat mass. Sport-practicing girls had more frequently sport-practicing mothers and higher scores on achievement motivation than nonsport-practicing girls. Active boys had more frequently sport-practicing fathers than inactive boys. No statistically significant correlation was found between moderate to vigorous physical activity and organized sports. Those children who are the most involved in organized sports are thus not necessarily the most active ones.