# Evaluation of Thorax Diameter Changes through Trunk Morphology and Different Running Intensities
## 3 Results
### Mediolateral Thorax Cross-Section  
The mediolateral cross-section IP showed a statistically significant effect of the exercise intensity when comparing the subjects as a whole without dividing them by morphology groups (intra-subject effect; F2,38 = 35.789, \(p\) < 0.001, \(\eta^{2}\) = 0.389), reaching a large effect size. From 45% HRR to 70% HRR, an increase of 1.369% in the mediolateral thorax cross-section was found (\(p\) < 0.001). Also, an increase of 2.026% was observed from 45% to 85% HRR (\(p\) < 0.001). Plus, a trend of significant difference was found (0.657%, \(p\) = 0.060) between 70% and 85% HRR. The main effect of the morphology groups was not significant as there were no differences when comparing them in the same running intensity. The data from the mediolateral cross-section IP are shown in Table 5 and Figure S3. However, when pair comparisons were conducted for each morphology group, all groups had the same behaviour, showing a significant increase in IP from 45% to 85% HRR (IP = 2.084%, \(p\) = 0.027; IP= 2.103%, \(p\) = 0.025 and IP = 1.892%, \(p\) = 0.034, respectively).  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{6}{c}{**Estimated Marginal Means—ATC * Morphology Group**} \\ \hline \multirow{2}{*}{**Morphology Group**} & \multirow{2}{*}{**ATC**} & \multirow{2}{*}{**Mean**} & \multirow{2}{*}{**SE**} & \multicolumn{2}{c}{**95\% Confidence Interval**} \\ \cline{5-6}  & & & & **Lower** & **Upper** \\ \hline \multirow{4}{*}{1} & ATC\_45\% & 4.14 o & 0.523 & 3.04 & 5.25 \\  & ATC\_70\% & 5.41 & 0.52 & 4.3 & 6.51 \\  & ATC\_85\% & 7.29 & 0.597 & 6.03 & 8.56 \\ \hline \multirow{4}{*}{2} & ATC\_45\% & 5.26 o & 0.619 & 3.95 & 6.57 \\  & ATC\_70\% & 5.9 & 0.616 & 4.6 & 7.21 \\  & ATC\_85\% & 8.25 & 0.706 & 6.75 & 9.74 \\ \hline \multirow{4}{*}{3} & ATC\_45\% & 4.83 o & 0.523 & 3.72 & 5.94 \\  & ATC\_70\% & 5.01 \# & 0.52 & 3.9 & 6.11 \\  & ATC\_85\% & 7.58 & 0.597 & 6.32 & 8.85 \\ \hline \multirow{4}{*}{Total} & ATC\_45\% & 4.69 o & 0.318 & 4.02 & 5.36 \\  & ATC\_70\% & 5.39 \# & 0.309 & 4.74 & 6.04 \\ \cline{1-1}  & ATC\_85\% & 7.65 & 0.353 & 6.91 & 8.39 \\ \hline \end{tabular} Key: SE: standard error; ATC\_45%: IP of anteroposterior thorax cross-section at a running intensity of 45% HRR; ATC\_70%: IP of anteroposterior thorax cross-section at a running intensity of 70% HRR; ATC\_85%: IP of anteroposterior thorax cross-section at a running intensity of 85% HRR. * Statistical difference between IP at 45% HRR and 70% HRR. # Statistical difference between IP at 45% HRR and 85% HRR. * Statistical difference between IP at 45% HRR and 85% HRR.  
\end{table}
Table 4: IP results of the anteroposterior thorax cross-section (ATC) among different exercise intensities and divided by morphology groups.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{6}{c}{**Estimated Marginal Means—MTC * Morphology Group**} \\ \hline \multirow{2}{*}{**Morphology Group**} & \multirow{2}{*}{**MTC**} & \multirow{2}{*}{**Mean**} & \multirow{2}{*}{**SE**} & \multicolumn{2}{c}{**95\% Confidence Interval**} \\ \cline{5-6}  & & & & **Lower** & **Upper** \\ \hline \multirow{4}{*}{1} & MTC\_45\% & 3.55 o & 0.383 & 2.75 & 4.35 \\  & MTC\_70\% & 5.01 & 0.419 & 4.13 & 5.89 \\  & MTC\_85\% & 5.63 & 0.481 & 4.63 & 6.64 \\ \hline \multirow{4}{*}{2} & MTC\_45\% & 3.31 o & 0.383 & 2.51 & 4.11 \\  & MTC\_70\% & 4.84 & 0.419 & 3.97 & 5.72 \\ \cline{1-1}  & MTC\_85\% & 5.41 & 0.481 & 4.4 & 6.42 \\ \hline \hline \end{tabular}
\end{table}
Table 5: IP results of the mediolateral thorax cross-section (MTC) among different exercise intensities and divided by morphology groups.