Reliability of countermovement jump,and isometric mid-thigh pull measurementafter a cycle ergometer VO2-max test. A pilotstudy within the frame of the Project: Relative Energy Deficit in Swedish Athletes

Abstract: Abstract Introduction In order to evaluate aerobic, power and strength abilities coaches typically has performed all the physical tests at the same testing session. Today there is a lack of instruments tested for reliability in that kind of setting. Aim The purpose of this study was to investigate intra-session reliability for countermovement jump (CMJ) and Isometric Midthigh Pull (IMTP) after a fatiguing cycle-ergometer VO2-maxtest. Method: A quantitative, descriptive, cross-sectional study design where 25 Swedish elite athletes, 11 women (age 26.9 ± 8.3 year, weight 63.3 ± 7.4 kg, length 169.8 ± 7.4 cm and BMI 21.9 ± 1.4) and 14 men (age 23.4 ± 2.9 year, weight 77.9 ± 12.4 kg, length 179.0 ± 8.3 cm and BMI 24.2 ± 2.0), from different sports were recruited through a stratified comfort selection from the initial survey study within the project: Relative Energy Deficit in Swedish Athletes (the REI-project). The study-participants performed physical testing in one test session, the test-protocol consisted of a incremental VO2-max cycle-ergometer test to fatigue followed by 3 attempts CMJ and 3 attempts IMTP. Results The relative reliability was excellent for both CMJ and IMTP (Intraclass correlation (ICC) 0,948 and 0,983 respectively), not surprisingly due to the heterogeneous population.  The absolute reliability was excellent as well (percentage of typical Error (TE%) 5,84 and 4,02, percentage of coefficient of variation (CV%) 6,81 and 7,63 respectively). Conclusion The CMJ and IMTP are intra-session reliable in measuring jump hight and isometric strength in a state of fatigue.