## 4 Discussion
The authors found significant (\(p<0.05\)) and positive correlations between the DSJ height and weightlifting performance during the snatch, clean and jerk, and weightlifting total (r = 0.75-0.78) and suggested that performing DSJs is highly specific to weightlifters for several reasons. First, the DSJ has a longer distance to accelerate the centre of mass of the lifter throughout the triple extension of the hips, knees, and plantar flexion of the ankles. This longer distance could, in turn, allow the weightlifter more time to apply force, which is common in weightlifting movements, as weightlifters work with a full range of motion (i.e., snatch and clean catch phases, overhead squats, and back and front squats to full depth) (2016; 2016). Second, because the snatch and clean start from a static position with the muscles stretched and require the lifter to exert rapid concentric forces against the floor with no previous countermovement, the DSJ could be a better reflection of the force exertion at the starting and catching positions of the snatch and clean (2016; 2017). In contrast, researchers have related the rapid stretch-shortening cycle of the CMJ with the double knee bending of the snatch and clean exercises and the rapid change in the direction of the jerk (2017; 2017). In our study, very strong to nearly perfect correlations were observed between the CMJ and DSJ propulsive net impulse and peak power and weightlifting performance during the snatch and clean and jerk (Figure 2), suggesting that these metrics evaluated during both tests could be a suitable option to assess the neuromuscular capabilities in top-level weightlifters. In this study, the CMJ and DSJ heights were significant (\(p<0.05\)) and strongly correlated with weightlifting performance (r = 0.65-0.71) for all subjects (Figure 2). However, when they were separated by sex, there were no significant correlations between the jump height and weightlifting performance in males and females (Table 2 and Figures 4 and 5). Weightlifters must generate a net impulse during the propulsive phase of each lift to increase the momentum of the system mass and ultimately transfer it to the barbell (2016; 2017). The higher the net impulse, the higher the system momentum transferred to the barbell, and, consequently, a higher barbell displacement may be achieved (2017). Similarly, during vertical jumps, weightlifters must generate a net impulse to increase the body mass momentum; the higher the relative net impulse, the higher the resulting take-off velocity, which ultimately determines the jump height. However, the jump height is dependent on the subject's body mass, and therefore, higher jump heights are biased to lighter subjects, although these investigations did not include weightlifters (2017; 2017). Since weightlifting is a sport that includes weight categories, some weightlifters usually go down in weight category prior to competitions and they may jump higher (i.e., positive change) with negative or no changes in their associated propulsive net impulse (2017). Consequently, the jump height may not reflect the actual neuromuscular capabilities in top-level weightlifters, especially when males and females are evaluated separately, and the use of force-time metrics such as the net impulse may be critical to adequately assess their ballistic performance. The utilization of force plates as an affordable option for practitioners has resulted in an increasing interest in force-time metrics and their associated methodology to assess the neuromuscular capabilities of weightlifters (2014; 2017). For example, [PERSON] et al. (2017) found that the CMJ propulsive impulse, which is dependent on the force generated and duration of the propulsion phase, was significantly and strongly correlated with weightlifting performance (\(p<0.004\), r = 0.68-0.82).