Maximal aerobic speed and V̇O2max were the strongest predictors of YYIR1 performance in professional soccer players, outperforming submaximal thresholds such as AT and RCP, and midfielders demonstrated greater relative acidosis tolerance capacity compared to defenders.
YYIR1 total distance was significantly associated with maximal aerobic speed in professional soccer players.
YYIR1 total distance was significantly associated with V̇O2max in professional soccer players.
YYIR1 total distance was not significantly associated with submaximal ventilatory thresholds (aerobic threshold or respiratory compensation point).
Midfielders demonstrated significantly higher relative acidosis tolerance capacity compared to defenders.
The study assessed buffering capacity and tolerance to metabolic acidosis alongside standard aerobic performance markers in professional soccer players.
This research suggests that in professional soccer players, the ability to run farther on the Yo-Yo Intermittent Recovery Test Level 1 (a common fitness test used in team sports) is most closely linked to two maximal aerobic qualities: maximal aerobic speed and maximum oxygen consumption (V̇O2max). Interestingly, submaximal markers measured during a laboratory treadmill test — specifically the aerobic threshold and the respiratory compensation point — were not significantly related to Yo-Yo test performance. This indicates that how well a player performs at their physiological ceiling may matter more for this field test than where their endurance thresholds fall during moderate exertion. The study also found meaningful differences between playing positions in how well players tolerate the buildup of acid in their muscles during intense exercise (acidosis tolerance). Midfielders showed significantly greater relative acidosis tolerance than defenders, which may reflect the high-intensity, repeated-sprint demands of the midfielder role during matches. However, no positional differences were found for buffering capacity or Yo-Yo test distance overall. This research suggests that coaches and sports scientists evaluating soccer players' fitness should pay particular attention to V̇O2max and maximal aerobic speed when interpreting Yo-Yo test results, as these maximal measures are the most meaningful physiological correlates of field test performance. The positional differences in acidosis tolerance also suggest that training programs targeting high-intensity effort tolerance may need to be customized based on a player's role on the field.
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Upload Your LabsFerreira R, Silvino V, Vilhena L, Santos M, Prado D. (2026). Association between Yo-yo intermittent recovery test, physiological markers of endurance performance, and buffering capacity in professional soccer players.. Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas. https://doi.org/10.1590/1414-431X2026e15230