Body weight and subcutaneous fat patterning in elite judokas

Abstract

Body weight and fat are major performance variables in many sports. Extreme weight reduction can lead to severe medical problems. Accurate body composition measurements are fundamental for both medical and performance optimization. Relative body weight in terms of mass index (MI1 = 0.53 M/(hs)), and in terms of body mass index (BMI = M/h 2) were determined (h:stature, s:sitting height, M:body mass). Subcutaneous adipose tissue (SAT) was measured using a recently standardized ultrasound (US) method. US thickness sums from eight body sites were measured in 26 female and 35 male judokas of various weight classes. Comparisons of US and skinfold results indicate that the latter can be severely misleading in competitive judokas. Mean MI1 of females was 22.8 kg m−2 (BMI:22.9 kg m−2), males: 26.7 kg m−2 (BMI:26.5 kg m−2), but individual differences MI1‐BMI were larger than 0.5 kg m−2 in 13 and larger than 1.0 kg m−2 in three cases. Medians of SAT thickness sums D I were three‐times higher in females (66.1 mm) than in males (21.8 mm), and the fat patterning differed significantly. Females had 8.6% (median) fibrous structures embedded in SAT, and males 20.2%. Both MI and BMI were not correlated with SAT. Mean pre‐competition weight loss was 4.3% (ie, 3.0 kg), and maximum was 9.2% (7.4 kg), indicating that modifications of weigh‐in procedures are urgently needed. DI‐values mirror the athletes' potential to reduce ballast fat instead of short‐term weight reduction by dehydration; however, weight loss and SAT measured some weeks before the competitions were not correlated. Further, US measurements and medical longitudinal observations are required for discussing the large individual variations and possible fat minimum demands.

Relative Body Weight and Standardised Brightness-Mode Ultrasound Measurement of Subcutaneous Fat in Athletes: An International Multicentre Reliability Study, Under the Auspices of the IOC Medical Commission

“…Figure 2a shows that the BMI is useless for assessing body fat in athletes: as expected [2], there was no correlation between BMI and SAT thicknesses sums. Similar results were found in several other groups, too [7,11,37]. Conversely, among anorexia nervosa patients, with extremely low BMI (below 17.5 kg m −2 ), some individuals may have subcutaneous fat thickness values comparable to those of healthy women [9,12].…”

“…SAT makes by far the largest part of total body fat (typically 80-90% of anatomically detectable fat mass [36]). The SAT thickness sums in females can be expected to be higher when the site EO is replaced by LT [7,25,37]. None of the measurement techniques for cross-sectional or longitudinal studies of body fat is capable of measuring on such a fine scale as US [2,27], and no other can quantify the amount of connective tissues embedded in the SAT ('fascias'), which forms a substantial part of SAT (4.0 to 29.3% in the group of elite athletes studied here).…”

Competitive Performance of Kenyan Runners Compared to their Relative Body Weight and Fat

“…According to preliminary normative data [28], two of them were in the category 'low' body fat, and one was in the category 'extremely low'. The median value of the whole female group was 58 mm (ranging from 20.2 to 82.1 mm), which is close to median values found previously in other sports: in a group of 16 elite female adult judokas, the median was 65 mm (ranging from 45 to 88 mm) [29], and the eight female athletes of the German National rowing team (U 19) had a median of 70 mm (48 to 79 mm) [30]. Compared to the male longdistance runners, the females' D I -median was about six times higher, indicating that adipose tissue, which has important endocrine functions [37], plays a substantial role in females.…”

“…The percentage of these fibrous structures with respect to the thickness D I was 13.9 % in women and 29.5 % in men. Lower amounts of embedded fibrous structures in women than in men were also found in elite judokas (8.6 %, and 20.2 %, respectively) [29], and in a mixed group of 76 elite athletes measured in five independent research centres (11 %, and 18 %, respectively) [16].…”

“…Seen from a health perspective: "There are no generally accepted optimum values for body weight or percentage of fat mass in different sports…" [6]. Data of this and of previous studies [16,29,30] clearly indicate that the search for optimum body fat values and cut-off criteria for raising the alarm has to distinguish between sexes and to consider that such limits may largely depend on genetic differences of the sexes and between individuals [2]. The question how to minimise the health risks to athletes who compete in weight-sensitive sports has been discussed in a consensus statement of the IOC Working Group on Body Composition, Health and Performance [6].…”