## 3 Results
### Changes in Athletes' Physical Function Indicators during Subalpine Training
#### 3.1.2 Changes in Blood Hormones and Serum Biochemical Indicators of Athletes  
Using training time as a within-group factor, a repeated-measures ANOVA found that the three indicators of C, BU, and CK in the blood of male athletes were significantly different from training time (\(p<0.01\)). C and BU increased significantly (\(p<0.01\)), and CK increased significantly (\(p<0.05\)) after entering the subalpine training. Then they began to decline slowly and began to rise significantly after the 5 th month (\(p<0.01\)); the fluctuations of C, BU, and CK in the blood of female athletes are relatively large, and the main effect of time is that C and BU were significantly different (\(p<0.01\)). There is no significant difference in CK (\(p>0.05\)). After 6 months of training, C and BU were significantly higher than before sub-altitude (\(p<0.05\) or \(p<0.01\)). CK increased significantly in the first month and reached its peak; compared with the fourth and fifth months, it decreased significantly (\(p<0.05\); Table 6; Figure 3). There were significant differences (\(p<0.01\) or \(p<0.05\)) in C and BU when comparing the different genders, with female athletes consistently having higher levels of C than male athletes and male athletes having higher levels of BU than female athletes; there were \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Time**} & \multicolumn{2}{c}{**C/(nmol/l)**} & \multicolumn{2}{c}{**BU/(mmol/L)**} & \multicolumn{2}{c}{**CK/(U/L)**} \\ \cline{2-6}  & **Male** & **Female** & **Male** & **Female** & **Male** & **Female** \\ \hline Before training & 478.49 \(\pm\) 79.96 & 572.15 \(\pm\) 44.01 & 6.71 \(\pm\) 1.03 & 5.67 \(\pm\) 1.09 & 301.52 \(\pm\) 138.96 & 181.00 \(\pm\) 58.99 \\
1 st month & 510.04 \(\pm\) 61.24 & 526.63 \(\pm\) 101.76 & 7.03 \(\pm\) 0.89 & 6.49 \(\pm\) 0.47 & 604.88 \(\pm\) 201.12 & 754.87 \(\pm\) 224.24 \\
2 nd month & 518.20 \(\pm\) 69.72 & 587.84 \(\pm\) 56.92 & 7.95 \(\pm\) 1.11 \({}^{\rm aa,hb}\) & 7.39 \(\pm\) 1.77 \({}^{\rm aa}\) & 483.96 \(\pm\) 151.68 & 256.13 \(\pm\) 97.73 \\
3 rd month & 526.97 \(\pm\) 73.96 & 659.48 \(\pm\) 48.87 & 7.74 \(\pm\) 128 \({}^{\rm aa}\) & 6.47 \(\pm\) 1.15 \({}^{\rm aa}\) & 273.36 \(\pm\) 98.65 & 160.13 \(\pm\) 33.63 \\
4 th month & 545.66 \(\pm\) 70.11 \({}^{\rm a}\) & 680.14 \(\pm\) 93.56 \({}^{\rm b}\) & 8.19 \(\pm\) 0.99 \({}^{\rm a,hb}\) & 7.36 \(\pm\) 1.15 \({}^{\rm aa}\) & 151.20 \(\pm\) 49.10 \({}^{\rm aa,hb,cc}\) & 125.75 \(\pm\) 38.45 \({}^{\rm b}\) \\
5 th month & 569.35 \(\pm\) 82.58 \({}^{\rm aa,b}\) & 604.63 \(\pm\) 100.06 & 7.74 \(\pm\) 1.01 \({}^{\rm b}\) & 7.22 \(\pm\) 1.03 \({}^{\rm aa}\) & 140.56 \(\pm\) 48.47 \({}^{\rm aa,hb,cc}\) & 100.38 \(\pm\) 21.82 \({}^{\rm b}\) \\
6 th month & 574.42 \(\pm\) 86.96 \({}^{\rm a,hb,d}\) & 662.85 \(\pm\) 84.60 \({}^{\rm b}\) & 8.06 \(\pm\) 1.13 \({}^{\rm aa}\) & 7.02 \(\pm\) 1.58 \({}^{\rm a}\) & 504.04 \(\pm\) 148.71 \({}^{\rm aa,cc,eff}\) & 257.75 \(\pm\) 89.67 \\ Time effects & \(p=0.002\) & \(p=0.038\) & \(p=0.001\) & \(p=0.001\) & \(p=0.001\) & \(p=0.000\) \\ \hline \hline \end{tabular} Notes: (1) a, aa means \(p<0.05\), \(p<0.01\) compared with before subalpine training, (2) b, bb means \(p<0.05\), \(p<0.01\) compared with the first month of subalpine training, (3) c, ce means \(p<0.05\), \(p<0.01\) compared with the second month of subalpine training. (4) d, dd means \(p<0.05\), \(p<0.01\) compared with the third month of subalpine training. (5) e, ee means \(p<0.05\), \(p<0.01\) compared with the fourth month of subalpine training. (6) f, ff means \(p<0.05\) and \(p<0.01\) compared with the fifth month of subalpine training.  
\end{table} 
Table 6: The results of changes in C, BU, and CK in the blood of athletes. Figure 3: The results of changes in C, CK, and BU in the blood of athletes: (**a**) Changes of C in blood at different times; (**b**) Changes of BU in blood at different times; (**c**) Changes of CK in blood at different times. Data are mean \(\pm\) SD.