The reliability, validity and usefulness of the 30-15 intermittent fitness test for cardiorespiratory fitness assessment in military personnel.

The objectives of this study were to investigate the reliability, validity, and usefulness of the 30-15 intermittent fitness test (30-15) in soldiers. The 34 infantry members of the Slovenian armed forces were recruited as participants. Participants performed the continuous incremental treadmill test (TR), a 2-mile run (2) test, and two 30-15 tests. Additionally, participants were divided into a highest-scoring group (HSG) and a lowest-scoring group (LSG) based on their scores on the Army Physical Fitness Test. A very high reliability ratings were observed for 30-15 measures, as follows: end-running speed (ERS) ERS (ICC = 0.971) maximal heart rate (HR) HR (IC = 0.960) and maximal relative oxygen consumption (VO) VO (ICC = 0.975) Although 30-15 measures demonstrated high correlations (r = 0.695-0.930) to the same measures of TR test, ERS, HR and VO were higher in the 30-15 (p > 0.05) Furthermore, ERS and predicted VO were higher in HSG compared to LSG, whereas HR did not differ. The results of this study show that the 30-15 test is a reliable, valid and useful tool for assessing cardiorespiratory fitness in the armed forces. Moreover, the ERS and predicted VOmax values derived from the 30-15 could be considered more sensitive markers of combat readiness than the parameters derived from the TR and 2 tests.Trial registration number: NCT05218798.