# Relationship Between the Yo-Yo Intermittent Recovery Test and Match Running Performance in Canadian Male Professional Soccer Players

## TL;DR

This study shows that the Yo-Yo Intermittent Recovery Test Level 1 is strongly linked to high-intensity running in professional male soccer matches.

## Contribution

The study provides new evidence on the predictive value of YYIRTL1 for in-game high-intensity running in professional soccer.

## Key findings

- YYIRTL1 strongly correlates with high-intensity running (r = 0.79) and high-speed running (r = 0.73).
- YYIRTL1 explains 63% of the variance in high-intensity running during matches.
- YYIRTL2 shows weaker or no significant correlations with match running performance metrics.

## Abstract

Despite the prevalence of the Yo-Yo Intermittent Recovery Tests Level 1 (YYIRTL1) and Level 2 (YYIRTL2) in elite soccer, knowledge surrounding their association and prediction of match performance is limited. This study investigated the association between respective tests and match running performance in male professional soccer players. High-intensity (HIR), high-speed (HSR), and sprinting (SPR) running distances were collected using a global positioning system from eleven professional male players who completed the YYIRTL1 and YYIRTL2. Associations between match performance and the YYIRT were assessed using correlational analyses, and the predictability of the YYIRT with match performance was assessed using univariate linear regression analyses. Strong correlations were found between YYIRTL1 and both HIR (r = 0.79) and HSR (r = 0.73). A moderate correlation was observed between YYIRTL2 and HIR (r = 0.42) and a weak correlation was observed between YYIRTL2 and HSR (r = 0.12). No correlation was observed between YYIRTL1 and SPR (r = 0.07) and a moderate, negative correlation was observed between YYIRTL2 and SPR (r = −0.21). Univariate regression analyses suggested that YYIRTL1 explained 63% of HIR variance, which YYIRTl2 did not, and that neither test suggested significant predictive ability in HSR or SPR. The YYIRTL1 is strongly associated with, and may predict, in-game HIR in Canadian male professional soccer players.