Feasibility of the 2-point method to determine the load−velocity relationship variables during the countermovement jump exercise

Two-point Method Applied in Field Conditions: A Feasible Approach to Assess the Load-Velocity Relationship Variables During the Bench Pull Exercise

“…Although using both MV and PV yielded the L-V relationship variables with acceptable reliability in this study, using PV provided the L-V relationship variables with greater ( L 0 ) or comparable ( v 0 and A line ) reliability compared with when MV was used to model the relationship. These results are in agreement with Pérez-Castilla et al (29) who demonstrated that the L-V relationship variables were more reliable with PV than with MV during the countermovement jump exercise (CV ratio = 1.33, 1.86 and 1.15 for L 0 , v 0 and A line , respectively). The lower reliability obtained for the L-V relationship variables obtained using MV may be mainly attributed to the measurement error derived from the arbitrary decisions about how to determine the exact start and end points of the lifting phase (14).…”

“…The L-V relationships were modeled considering 2 velocity variables (MV and PV) and using 3 different methods: standard multiple-point (i.e., using data points acquired from the 6 loads for the L-V modeling), modified multiple-point (i.e., excluding the data point that most reduced the r 2 of the linear regression of the standard multiple-point method for the L-V modeling), and 2point (i.e., using data points acquired from only 2 loads for the L-V modeling) (4,29). Specifically, for the modified multiple-point method, the L1, L3, L4, and L6 were omitted in 57, 13, 2, and 20 of 92 linear regressions, respectively.…”

“…Indeed, force outputs are not necessary for modeling the load-velocity (L-V) relationship to assess maximal neuromuscular capabilities (25,26,29), thereby reducing the amount of extrapolation (N vs. kg against velocity) to v 0 . Therefore, it is not surprising that the L-V relationship variables (load-axis intercept [i.e., load at zero velocity; L 0 ], velocity-axis intercept [i.e., velocity at zero load; v 0 ], and the area under the L-V relationship line [i.e., A line 5 L 0 3 v 0 /2]) have not only provided high reliability (25,26,29) but also high concurrent validity with respect to other traditional tests (25,26). Moreover, the variables derived from the L-V relationship were recently shown to be sensitive enough to differentiate between rowers of different age categories and to be associated with a 2,000-m rowing ergometer performance (28).…”

“…The linearity of the F-V and L-V relationships is typically verified through the coefficient of determination (r 2 ). Although the F-V and L-V relationships have proven to be very strong in various exercises (r 2 $ 0.91) (15,23,25,29), a new method (this will be referred to as "modified multiple-point" in the further text) that excludes the data point most reducing the r 2 of the standard multiple-point method has been proposed to reduce performance variation (22). In this regard, Fessl et al (4) did not find differences in the reliability of the F-V relationship parameters between multiple-point methods in ski jumping athletes, but reliability worsened-especially for the modified multiple-point method-in sport science students probably because the most extreme data points were removed from the F-V modeling (6,23).…”

“…A large body of research has shown that the 2-point method is highly reliable and valid with respect to the multiple-point method to obtain the F-V relationship parameters in a variety of exercises (8,23,32). More recently, Pérez-Castilla et al (29) found that the 2-point method provided the L-V relationship variables during the countermovement jump exercise with acceptable reliability, especially using the peak velocity (PV), but the concurrent validity of the 2-point method with respect to the multiple-point method was only acceptable for the mean velocities (MVs). It is worth highlighting that in all previous studies, the 2-point method was extracted from a testing procedure based on the multiple-point method.…”