# A Systematic Literature Review of Intelligent Data Analysis Methods for Smart Sport Training
## 6 Discussion
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Sport** & **P** & **R** & **C** & **E** \\ \hline Basketball & / & 4 & 4 & 2 \\ Cycling & 4 & 1 & 1 & 1 \\ Fitness (gym) & 1 & 3 & / & / \\ Rowing & / & 1 & 3 & 2 \\ Running & 3 & 8 & 7 & 6 \\ Shooting & 1 & 3 & 3 & 2 \\ Soccer & 7 & 5 & 4 & 6 \\ Swimming & 2 & 3 & 3 & 1 \\ Table Tennis & / & 3 & 1 & / \\ Tennis & / & 4 & 3 & 2 \\ Triathlon & 1 & / & 2 & 2 \\ Volleyball & 2 & 3 & 2 & 2 \\ Weight Lifting & 1 & 7 & 6 & 1 \\ Aikido & 1 & / & / & / \\ Archery & 1 & / & / & 1 \\ Badminton & 1 & 1 & 1 & 1 \\ Climbing & / & 1 & / & / \\ Counter Movement Jumping & / & 1 & 1 & 1 \\ Cricket & 2 & 1 & 1 & 1 \\ Fencing & 1 & 1 & 1 & / \\ (American/Australian) Football & 2 & 2 & 2 & 2 \\ Golf & / & 2 & 2 & / \\ Hammer Throwing & / & 1 & / & / \\ Handball & 1 & 1 & 1 & 1 \\ Hockey & / & 1 & 1 & 1 \\ Karate & / & 2 & 1 & / \\ Kickboxing & 1 & 1 & 1 & / \\ Ski Jumping & / & / & / & 1 \\ Skiing & / & 1 & 1 & / \\ Tai-chi & 1 & 1 & 1 & / \\ Yoga & / & 1 & / & / \\ _General_ & 6 & 12 & 11 & 9 \\ \hline
**Total** & **39** & **76** & **64** & **45** \\ \hline \hline \end{tabular}
\end{table} 
Table 20: Count of how many times individual training stages were researched. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{3}{c}{**Smart Sport Training Stage**} \\ \cline{2-4}  & **Planning** & **Realization** & **Control** & **Evaluation** \\ \hline Idea & 14 & 20 & 27 & 15 \\ Prototype & 23 & 52 & 34 & 27 \\ Control & 2 & 4 & 3 & 3 \\ Validation & / & / & / & / \\ \hline \hline \end{tabular}
\end{table} 
Table 21: Count of research by training stage and Technology Readiness Level (TRL) abstracted levels. * Planning--no research in the domains of basketball, hammer throwing, rowing, table tennis, tennis, climbing, golf, hockey, karate, ski jumping, skiing, and yoga. * Realization--no research in the domains of triathlon, aikido, archery, and ski jumping. * Control--no research in the domains of fitness (gym), aikido, archery, hammer throwing, ski jumping, and yoga. * Evaluation--no research in the domains of fitness (gym), table tennis, aikido, climbing, fencing, golf, hammer throwing, karate, kickboxing, skiing, Tai-chi, and yoga. The datasets used in the studies were mostly private data collections, which hinders the ability for verification and validation of published results. Only six studies used and referenced publicly available datasets as presented in Table 22. The vast majority of research used private datasets based on real data. The Dataset column presents the reference to the used dataset, in the Data type column the data were identified as real or synthetic, based on their origin, and in the Studies column, the studies using the mentioned dataset are referenced. All the studies where private datasets were used, or from which we could not identify the used dataset, were classified under the Private dataset rows. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Dataset** & **Sport** & **Data Type** & **Studies** \\ \hline
[161] & Soccer & Synthetic & [88,89] \\
[94] & Table Tennis & Real & [94] \\
[162] & Tennis & Real & [102] \\
[163] & Weight Lifting & Real & [114] \\
[164,165] & Skiing & Real & [121] \\ Private Dataset & / & Synthetic & [55] \\ Private Dataset & / & Real & [46,48–50,52,54,56–76,78–87, \\  & & & 90–93,95–101,104–110,112, \\  & & & 113,115–120,122,123,125,128, \\  & & & 130–138,140–149,152,155, \\  & & & 156] \\ \hline \hline \end{tabular}
\end{table} 
Table 22: Identified datasets and studies using them. Figure 6: Relative frequency of intelligent methods used by the proposed taxonomy, rounded to three significant digits. This, however, does not mean that free, open, and public datasets from the domain of SST do not exist. There are already a significant number of them (e.g., [166, 167, 53, 168, 169, 170, 171]), together with websites that publish sanitized datasets (e.g., [172]), it remains a fact that they are not used enough.