# Body Composition in Karate: A Dual-Energy X-ray Absortiometry Study
## 4 Discussion  
This work investigated the body composition of a large sample (n = 58) of karate participants using the accurate DXA technology. To the best of our knowledge, the sample size in this work is unparalleled in previous literature investigating body composition in adult karatekas. All participants were black belt, currently competing at the national and international level, and DXA scans were taken at least 10 days before or after competition, i.e., presumably before/after acute weight loss/recovery (a practice frequently adopted by athletes in weight category sports) [38] had taken place. Therefore, we are confident that the reported data reflect the current body composition of karatekas. The reference values for WB and regional body composition were produced for males across weight divisions. In the whole sample of athletes (males and females), the findings showed possible right-left asymmetry in the limb body composition and the ability of appendicular FFSTM (which fairly approximate the total body amount of skeletal muscle [39]) to reliably predict the content and areal density of bone mineral, especially in the limbs. Previous work using DXA [11] in a small number (n = 14) of male karatekas showed lower WB FM and higher WB FFSTM in comparison with the male karatekas (n = 43) participating in this study (8.3% vs. 15.1% and 61.2 kg vs. 57.4 kg, respectively). Higher average values were also found for WB BMC (3.7 kg vs. 2.8 kg) and aBMD (1.36 g/cm\({}^{2}\) vs. 1.25 g/cm\({}^{2}\)). Age and BMI were similar in the two groups. An explanation for such a discrepancy can be the different volume of training in the two groups (at least 18 h/w vs. 8 h/w on the average; participants in the [PERSON] et al. [11] study were admittedly highly trained athletes), which is expected to have an important effect on soft tissue and bone mineral, associated with higher energy expenditure, muscle mass adaptation to high training, and higher overall impact load on bone. As reported by [PERSON] et al. [10], the WB %FM of elite male karatekas (estimated by skinfolds) ranged from 7.4 to 16.8%, showing high variability among countries and suggesting that higher %FM \"does not prevent from high-level performance\" in karate. In females, WB %FM (average value, 18.6%) was only reported for seven Botswana national-level athletes. Subsequent studies employing BIA [12; 13; 14] or skinfolds [15; 16; 17] for body composition assessment in adult (>18 years) karatekas showed WB %FM ranging from about 10% to 16% in males and from 23% to 24% in females. Our data confirm and expand on these finding by using a more accurate method such as DXA to show that karate participants competing at the national and international level are well fit (especially males), but they do not typically reach the low (<10%) WB %FM found in other sports (e.g., cycling). Our findings are supported by DXA data collected in other combat sports showing WB %FM averaging 14% and 25% (for males and females, respectively) in judo, and 13% and 22% in wrestling participants [40]. Similarly, [PERSON] and colleagues [41] showed that the median (50 th) percentile for WB %FM was about 12% (males) and 23% (females) in a sample of judo and wrestling athletes. The stature-adjusted body composition indices (FMI, FFMI) were statistically significantly lower (FMI) and higher (FFMI) in the male than female karatekas, with the exception of trunk FMI, which was similar by sex (males, 1.56 kg/m\({}^{2}\); females, 1.82 kg/m\({}^{2}\)). This indicates that sex-related differences in adipose tissue distribution in karatekas are essentially located in the limbs, independently of stature. The WB FMI and FFMI were 3.6 kg/m\({}^{2}\) and 4.9 kg/m\({}^{2}\), and 17.7 kg/m\({}^{2}\) and 16.2 kg/m\({}^{2}\) in the males and females, respectively.