## 3 Results
### Selection and Description of Studies  
The search of literature databases resulted in 190 initially identified studies. One hundred and thirty (130) articles were discarded based on their titles or abstracts. Sixty (60) full texts were taken into consideration and fully read, and 21 of them were selected for the final review. More details concerning the process of identifying and searching \begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline \multicolumn{11}{c}{**Criterion**} \\ \hline
**Study** & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** & **11** & \(\sum\) \\ \hline [PERSON] et al., 2017 & Y & N & N & N & N & N & Y & Y & Y & Y & 4 \\ \hline [PERSON] et al., 2017 & Y & N & Y & N & N & Y & N & Y & Y & Y & Y & 6 \\ \hline [PERSON] et al., 2016 & Y & N & N & N & N & Y & N & Y & Y & Y & Y & 5 \\ \hline [PERSON] et al., 2016 & Y & N & N & N & N & N & N & N & Y & Y & Y & 3 \\ \hline [PERSON] et al., 2015 & Y & N & N & N & N & N & N & Y & Y & Y & Y & 4 \\ \hline [PERSON] \& [PERSON], 2014 & Y & N & N & Y & N & N & N & Y & Y & Y & Y & 5 \\ \hline [PERSON] et al., 2013 & Y & N & N & Y & N & Y & N & Y & Y & Y & Y & 6 \\ \hline [PERSON] et al., 2019 & Y & N & N & N & N & N & N & Y & Y & Y & Y & 4 \\ \hline [PERSON] et al., 2020 & Y & N & N & N & N & N & N & Y & Y & Y & Y & 4 \\ \hline \hline \end{tabular} Legend: 1—eligibility criteria were specified, 2—subjects were randomly allocated to groups, 3—allocation was concealed, 4—the groups were similar at baseline regarding the most important prognostic indicators, 5—there was blinding of all subjects, 6—there was blinding of all therapists who administered the therapy, 7—there was blinding of all assess who measured at least one key outcome, 8—measures of all therapists who administered the therapy, 7—there was blinding of all assess who measured at least one key outcome, 8—measures of at least one key outcome were obtained from more than 80% of the subjects initially allocated to the group (dropouts, 9—all subjects for whom outcome measures were available received the treatment or control conditions as allocated or, where this was not the case, data for at least one key outcome were analyzed by “intention to treat”, 10—the results of between-group statistical comparisons are reported for at least one key outcome, 11—the study provides both point measures and measures of variability for at least one key outcome, Y—criterion is satisfied, N—criterion is not satisfied; \(\sum\)—total points awarded.  
\end{table} 
Table 1: _Cont._ \begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline \multicolumn{11}{c}{**Criterion**} \\ \hline
**Study** & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** & **11** & \(\sum\) \\ \hline [PERSON] et al., 2008 & Y & Y & N & N & N & N & N & Y & Y & Y & Y & 5 \\ \hline [PERSON] et al., 2008 & Y & Y & Y & N & N & Y & N & Y & Y & Y & Y & Y & 7 \\ \hline [PERSON] et al., 2008 & Y & Y & Y & N & N & N & Y & N & Y & Y & Y & Y & 7 \\ \hline [PERSON] et al., 2009 & Y & N & N & N & N & N & N & Y & Y & Y & Y & Y & 4 \\ \hline [PERSON] et al., 2011 & Y & N & N & N & Y & Y & N & Y & Y & Y & Y & 6 \\ \hline [PERSON] et al., 2011 & Y & N & N & N & N & N & N & Y & Y & Y & Y & 4 \\ \hline [PERSON], 2020 & Y & N & Y & N & Y & Y & N & Y & Y & Y & Y & Y & 7 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: PEDro Scale for studies where IFT 30–15 is used for training programming. for studies are been presented in the diagram (Diagram 1). Overall, 21 scientific papers were addressed in this study: (a) when the IFT 30-15 is used to verify validity, reliability and aerobic capacity assessment (15), (b) when the IFT 30-15 is used as a tool in training programming (6). In general, the IFT 30-15 was used in those publications on a sample of professional or amateur, young or elite players of team sports. The selected studies and all their variables are presented in Tables 3 and 4.