# Selection of Posture for Time-Trial Cycling Events
## 2 Materials and Methods
### Postures, Cyclists, and Bicycles Tested  
Five cyclists voluntarily participated with their bicycles in the study. All subjects gave their informed consent for inclusion before they participated in the study. The study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the Ethics Committee of Pontificia Universidad Javeriana (under the project identification \"Effect of cyclist's posture on its performance and interaction with the bicycle\" with the code DOC-ING-131-2018). Different types of riders and bicycles were included in the study with the objective of exploring the results obtained for riders and bicycles with specific characteristics. The group of cyclists was selected to include riders of both genders (four male and one female), with different ages (a male rider for each of the age categories Senior/Elite, Masters A, Masters B, and Masters C), and different anthropometrical characteristics (four classified as healthy weight and one as overweight). The common characteristics of the group of riders included in the study are that they were recreational level cyclists, had experience in road cycling, had participated in cycling or triathlon races, and had experience riding in time-trial postures with aerobars. In addition, the participants reported they had no injuries that could affect their cycling performance. Finally, considering that all of the tests of the study were performed in a city located at an altitude of 2600 m above sea level, only cyclists that were adapted to this altitude were included. This was verified to avoid possible effects of altitude on the power output of cyclists, such as those reported by [PERSON] et al. (2016). To this end, it was checked that all the cyclists lived in the same city for at least five years. Table 1 summarizes the main characteristics of the cyclists that participated in the study.  
The riders performed the tests with their own bicycles. For this reason, different types of bicycles, such as endurance, time trial, and aero road bicycles, of different qualities, were included in the study. The bicycles of the participants were used with the intention of obtaining results that represent the actual riding conditions of each cyclist. The use of different bicycles could affect the test results (especially power delivery capacity and pressure on contact areas) because the riders would require extensive adaptation periods to other bicycles. Table 2 presents the main characteristics of the bicycles used by each cyclist. The riders performed the tests using standard cycling equipment (i.e., cycling helmet, short sleeve cycling jersey, padded cycling shorts, and clipless pedal shoes).  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Rider 1** & **Rider 2** & **Rider 3** & **Rider 4** & **Rider 5** \\ \hline Mass (kg) & 92 & 73 & 73 & 72 & 59 \\ Height (m) & 1.76 & 1.83 & 1.78 & 1.72 & 1.67 \\ Body mass index (kg/m\({}^{2}\)) & 29.7 & 21.8 & 23.0 & 24.3 & 21.2 \\ Age (years) & 42 & 30 & 39 & 26 & 38 \\ Cycling experience (years) & 9 & 9 & 20 & 5 & 17 \\ Gender & Male & Male & Male & Male & Female \\ \hline \hline \end{tabular}
\end{table}
Table 1: Characteristics of the riders included in the study.  
Different variables can be set to define the posture of a cyclist when riding in aerobars. For this study, the posture of the cyclist was varied by changing the height of the aerobars. The other variables of the bicycle geometry remained constant. Two postures with different aerobars' heights were defined for the implementation of the methodology. The aerobars' heights were set at the highest and lowest configurable limits of the bicycle (namely ABh and ABI, respectively). The configurable limits of the aerobars' heights for each bicycle are presented in Table 2. Figure 1 presents the silhouettes of the cyclists in the sagittal plane riding in the tested postures.