title: Reliability and smallest worthwhile difference of the NFL-225 test in NCAA Division I football players.
abstract: The NFL-225 test is widely used to assess the strength level and evaluate the progress of college football players during resistance training. Despite the studies evaluating the validity of this test, there are no reports assessing its reliability. The purpose of this study was to determine the reliability and smallest worthwhile difference (SWD) of the NFL-225 test in Division I college football players. Seventy-two players were assessed for more than 3 weeks for the number of repetitions completed with a constant load of 102.3 kg (225 lbs) during winter conditioning. Test sessions occurred on the same day and at the same time 1 week apart. Intraclass correlation coefficients (ICCs) between weeks 1 and 2 (ICC = 0.987), weeks 2 and 3 (ICC = 0.981), and across weeks 1, 2, and 3 (ICC = 0.988) indicated high relative reliability. A small technical error (TE) (TE = 0.5 repetitions) provided strong absolute reliability. The SWD suggests that a change in performance of 3 repetitions or more after training would indicate a meaningful improvement in performance for this test.
authors: Departments of 1Athletic Performance; and 2Physical Therapy, University of Missouri, Columbia, Missouri; 3Department of Physical Education, Center for Physical Development Excellence, United States Military Academy, West Point, New York; 4Human Performance Laboratory, Truman State University, Kirksville, Missouri; and 5Department of Physiology, A. T. Still University of Health Sciences, Kirksville, Missouri.
authors: J Bryan
authors: JB
authors: Mann
authors: Pat J
authors: PJ
authors: Ivey
authors: William F
authors: WF
authors: Brechue
authors: Jerry L
authors: JL
authors: Mayhew
mesh_terms: D005080:Exercise Test; D005538:Football / Q000502:physiology*; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology; D015203:Reproducibility of Results; D055070:Resistance Training; D014481:United States; D014495:Universities; D014891:Weight Lifting / Q000502:physiology; D055815:Young Adult