Submaximal field testing validity for aerobic fitness assessment in recreational football

Submaximal field tests are especially recommended when repeated testing is warranted. This study aimed at assessing the validity of the submaximal versions of the Yo-Yo intermittent tests in male recreational football players in untrained and trained status. The participants’ (n = 66; age 39.3 ± 5.8 years, VO _2max 41.2 ± 6.2 mL·kg ⁻¹·min ⁻¹, body mass 81.9 ± 10.8 kg, height 173.2 ± 6.4 cm) heart rate after 2 minutes (HR _2min) during the level 1 (YYIE1 _HR2min) and 2 (YYIE2 _HR2min) versions of the Yo-Yo intermittent endurance test and the level 1 version of the Yo-Yo intermittent recovery test (YYIR1 _HR2min) was plotted against individual VO _2max values. Thirty-two participants performed all the tests after a 12-week recreational football intervention for test responsiveness. Associations between VO _2max and YYIE1 _HR2min were large to small (P =.0001). Large to trivial associations were found between YYIE2 _HR2min, YYIR1 _HR2min, and VO _2max (P <.01). Maximal Yo-Yo performances were large, significant, and inversely related to HR _2min (−0.68 to −0.49, P <.0001). Pre- to post-intervention ICC values were good for YYIE1 _HR2min and YYIE2 _HR2min, and excellent for YYIR1 _HR2min. Post-intervention associations between HR _2min and Yo-Yo maximal performances were large to very large (−0.55 to −0.72; P <.002, n = 32). Training-induced changes in VO _2max moderately correlated with YYIR1 _HR2min (−0.48; P =.007; n = 32). HR _2min lower than 89%, 98%, and 91% HR _max for YYIE1 _HR2min, YYIE2 _HR2min, and YYIR1 _HR2min, respectively, may be considered as signs of good to excellent VO _2max levels. Since in the YYIE1 _HR2min, the participants attained 84% HR _max and test specificity increased for HR _2min values <89%, this test may be the preferred choice when repeated assessment of aerobic fitness, using submaximal intermittent Yo-Yo tests, is considered in recreational football.