## 2 Materials and Methods
### Procedures  
Before experiments, participants attended an orientation session to familiarize themselves with the rowing technique and the different rowing stroke rates. Participants practiced rowing until they could maintain the indicated rowing cadence and perform the correct rowing movement. A professional rowing instructor taught each participant the rowing technique and confirmed the correction of movements. The rowing strokes can be divided by a drive phase and a recovery phase. Participants were taught to follow several principles: (1) the drive phase is initiated with a push from the legs, followed by the hips beginning to open, and finally the arms begin to draw the handle to the body once the legs are fully extended and the back is vertical. (2) The handle finishes about half way up the body and the elbows follow the line of the handle and the wrists stay in line with the forearm. (3) The recovery is initiated with the arms straightening, followed by the body pivoting from the hips before the legs bend, and finally the legs flex until the shins are vertical. (4) Throughout the co-ordination of the drive and recovery phases, the back should remain in a neutral position.  
In the orientation session, the rowing instructor observed that some participants could not keep up with the fast cadence (36 bpm) after 10 consecutive strokes, resulting in incorrect and inconsistent movements, even though they had been trained. Thus, this study selected the number of strokes in each rowing test as 10 strokes to ensure that all the participants' movements during the rowing were cadenced, correct, and consistent.  
On the day of the experiment, participants first performed a 7-min warm-up, including 2 min of shoulder, ankle, and wrist activities and 5 min of full body stretches. After participants finished warming up, the wireless NIRS device was attached to the L4 part of the right erector spinae and the HR monitor was worn (Forerunner 920 XT GPS; Garmin, Taiwan). The order of the rowing tests was then randomly determined. Before each test, the air seat cushion pressure was adjusted in accordance with the test condition. The pre-exercise period began with the rowing test; during this period, the participant sat static on the rowing machine (Oxford II, Horizon Fitness, Inc., Taiwan) for 1 min. Next, in the exercise period, the participant performed 10 strokes in accordance with the cadence of the  
\begin{table}
\begin{tabular}{l c c c c c c c c c c c} \hline \hline  & \multicolumn{6}{c}{**Physiological Measurement**} & \multicolumn{6}{c}{**Pull Force Measurement**} \\ \hline  & \multicolumn{2}{c}{**All (n = 25)**} & \multicolumn{2}{c}{**Male (n = 13)**} & \multicolumn{2}{c}{**Female (n = 12)**} & \multicolumn{2}{c}{**All (n = 12)**} & \multicolumn{2}{c}{**Male (n = 6)**} & \multicolumn{2}{c}{**Female (n = 6)**} \\ \cline{2-11}  & **Mean** & **SE** & **Mean** & **SE** & **Mean** & **SE** & **Mean** & **SE** & **Mean** & **SE** & **Mean** & **SE** \\ \hline Age (yrs) & 22.4 & 1.17 & 20.5 & 0.21 & 24.5 & 2.32 & 26.4 & 3.33 & 20.2 & 0.17 & 32.7 & 5.76 \\ Body mass index (kg/m\({}^{2}\)) & 23.1 & 0.84 & 25.1 & 1.19 & 21.0 & 0.86 & 23.3 & 0.88 & 25.0 & 1.15 & 21.7 & 1.01 \\ Body fat (\%) & 23.6 & 0.86 & 21.5 & 1.11 & 25.9 & 0.99 & 23.8 & 1.47 & 20.7 & 1.57 & 27.0 & 1.76 \\ Skeletal muscle (\%) & 31.0 & 0.69 & 33.9 & 0.52 & 27.8 & 0.36 & 30.7 & 1.13 & 34.0 & 0.84 & 27.5 & 0.85 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Participant characteristics.  
metronome and then rested for 1 min (recovery period). NIRS, HR, and RPE data were collected during the tests. During the experiment, the resistance of the rowing machine was set to the lightest setting.