## 2 Materials and Methods  
### Study Participants and Procedures  
This quantitative observational cross-sectional study in design was carried out between 2018 and 2020 in Lithuania. The study was conducted on Lithuanian professional male athletes (N = 62) engaged in physical activity for Olympic disciplines such as Greco-Roman wrestling (N = 32), boxing (N = 17), and judo (N = 13). All athletes were voluntarily recruited and selected according to the list approved by the Lithuanian National Olympic Committee. Considering that 62 Lithuanian professional male athletes competing in combat sports constituted the whole target population, the determined representative sample size is equal to 54 cases at a 95% confidence level with a 5% margin of error [41]. The quota random sampling method was used to form a representative sample size for the study.  
The inclusion characteristics were as follows: (1) professional male athletes with \(\geq\)4 years (one Olympic cycle) of regular practice of combat sports; (2) participants at national/international competitions and/or candidates for the Olympic Team; (3) participants in the preparatory period (non-competition or pre-competition phase); (4) participants trained under the 'Tokyo 2020' program approved by the Lithuanian National Olympic Committee; (5) participants who followed a 6-day workout schedule plan regularly (\(\geq\)12 sessions of combat sports a week). The exclusion criteria were set as follows: (1) male athletes who were in the act of weight cutting; (2) participants who did not agree to participate in the study as volunteers.  
Finally, originating from four major Lithuanian regions, namely Samogitia (western Lithuania), Auksatitija (central and eastern Lithuania), Dzukija (south-eastern Lithuania), and Sudovia (south-northern Lithuania), 52 professional male athletes aged 21.6 \(\pm\) 3.4 years competing in combat sports were included and consequently allocated into three groups: Greco-Roman wrestlers (n = 29), boxers (n = 14), and judokas (n = 9). The mean training experience of combat sports athletes was 7.5 \(\pm\) 3.4 years. Due to the constant tendency of weight cycling, combat sports athletes were not recruited through the pre-competition phase or the competition phase. All combat sports athletes who were enrolled in the study during the general preparatory phase had been selected during the early part of this period and targeted the development of a general physical base. The sports workouts were performed 5.6 \(\pm\) 0.8 days per week, while the average duration of workout sessions was 152.3 \(\pm\) 35.5 min per day. In addition, Table 1 displays the weight categories in which male athletes from combat sports were competing.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Weight Classes (Upper Limit in kg)** & **Wrestlers (\%)** & **Judokas (\%)** & **Boxers (\%)** \\ \hline
60 kg 12; fbyweight (52 kg) 3  & 17.2 & 44.4 & 14.3 \\
67 kg 16; 66 kg 2; featherweight (57 kg) 3  & 17.2 & 22.2 & 50 \\
77 kg 17; 73 kg 2; lightweight (63 kg) 3  & 24.1 & – & 14.3 \\
87 kg 18; 81 kg 2; featherweight (69 kg) 3  & 31 & – & – \\
97 kg 19; 90 kg 2; middleweight (75 kg) 3  & 3.4 & 22.2 & 7.1 \\
130 kg 1; 100 kg 2; light heavyweight (81 kg) 3  & 6.9 & – & 7.1 \\ \textgreater{}100 kg 2; heavyweight (>91 kg) 3  & – & 11.1 & – \\ Super heavyweight (>91 kg) 3  & – & – & 7.1 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Weight classes for elite male athletes from different combat sports.