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.