## 3 Results
### HRV Changes  
HR, Ln RMSSD, and Ln SDNN changes are presented in Figure 1B-D. The baseline was 49.1 \(\pm\) 3.5 bpm, 4.7 \(\pm\) 0.4 ms, and 4.9 \(\pm\) 0.3 ms for HR, Ln RMSSD, and Ln SDNN, respectively.  
During the two weeks preceding the lockdown, a small decrease (\(-\)4.6 \(\pm\) 4.8%) in resting HR was observed from baseline values, whereas changes in Ln rMSSD and Ln SDNN were unclear. During the lockdown, a small to large increase in resting HR was observed (+9.2 \(\pm\) 5.4%). For Ln rMSSD and Ln SDNN, a small to moderate decrease was observed (\(-\)6.5 \(\pm\) 3.4% and \(-\)5.3 \(\pm\) 3.1% for Ln RMSSD and Ln SDNN, respectively). After the end of lockdown, differences between baseline values became unclear after 5 weeks for Ln rMSSD resting HR. For the final four weeks of the study, a small to moderate decrease in resting HR was observed (\(-\)5.4 \(\pm\) 4.8%), along with a small to moderate increase in Ln rMSSD from baseline values (5.3 \(\pm\) 2.1%). Unclear results were observed for Ln SDNN after the lockdown period. Detailed HRV values are provided in Table 2.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{**Training Period**} & \multicolumn{1}{c}{**Date**} & \multicolumn{1}{c}{**Monday**} & \multicolumn{1}{c}{**Tuesday**} & \multicolumn{1}{c}{**Wednesday**} & \multicolumn{1}{c}{**Thursday**} & \multicolumn{1}{c}{**Friday**} & \multicolumn{1}{c}{**Saturday**} & \multicolumn{1}{c}{**Sunday**} \\ \hline \multirow{3}{*}{Baseline} & AM & Swimming & Swimming & Swimming & Swimming & Swimming & Swimming & Swimming & Rest \\  & PM & Swimming + ST & Swimming + ST & Swimming + ST & Swimming + ST & Swimming + ST & Rest & Rest \\  & AM & Swimming & Swimming & Swimming & Swimming & Swimming & Swimming & Rest \\  & PM & Swimming + ST & Swimming + ST & Swimming + ST & Swimming + ST & Swimming + ST & Rest & Rest \\  & AM & Aerobic & Flexibility & Aerobic & Flexibility & Aerobic & SIT & Aerobic & Rest \\  & PM & ST & ST & Flexibility & ST & ST & SIT & Rest \\  & AM & Aerobic & Aerobic & Aerobic & Aerobic & Aerobic & Rest & Rest \\  & PM & ST & ST & ST & ST & ST & SIT & Rest \\  & PM & ST & ST & ST & SIT & SIT & Rest & Rest \\  & AM & Swimming & Swimming & Swimming & Swimming & Rest & Rest \\  & PM & Swimming + ST & ST & Swimming + ST & SIT & Swimming + ST & Rest & Rest \\  & AM & Swimming & Swimming & Swimming & Swimming & Swimming & Swimming & Rest \\  & PM & Swimming + ST & SIT & Swimming + ST & Swimming + ST & Swimming + ST & Rest & Rest \\ \hline \multicolumn{1}{c}{Note: BEF = before lockdown; LOCK = during lockdown; AFT1 = one week after lockdown; AFT2–3 = two to three weeks after end of lockdown; AFT4–5 = four to five weeks after end of lockdown; AFT6–9 = six to nine weeks after end of lockdown; ST = strength training.} \\ \end{tabular}
\end{table}
Table 1: Overview of the training program performed during each period of the study.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{} & \multicolumn{4}{c}{**Heart Rate**} & \multicolumn{4}{c}{**Ln RMSSD**} & \multicolumn{4}{c}{**Ln SDNN**} \\ \hline
**Weeks** & **ES** & **CL** & **Inference** & **\(\boldsymbol{p}\)-Value** & **ES** & **CL** & **Inference** & **\(\boldsymbol{p}\)-Value** & **ES** & **CL** & **Inference** & **\(\boldsymbol{p}\)-Value** \\ \hline  
0.25 & 0.49 & 6/36/58 & 0.35 & 0.38 & 0.42 & 78/20/2 & 0.13 & 0.52 & 0.51 & 86/12/2 & 0.10 \\ \hline \end{tabular} Note: Week 0 represents baseline measures. Weeks 1–2 represent the two weeks before lockdown commenced. Week 3 represents the first Monday of lockdown. Weeks 4–11 represent the weeks during lockdown. Weeks 12–20 represent the weeks after lockdown. Inference shows likelihood of changes being beneficial, trivial, and harmful. X = no data available.  
\end{table}
Table 2: Changes in mean as Cohen effect size (ES) and \(\pm\)90% confidence limits (CL) with quantitative chances (inference) of substantial differences for heart rate (HR), Ln RMSSD