Purpose: To explore the association of the load-velocity (L-V) relationship variables and ability to maintain maximal mechanical performance during the prone bench-pull exercise with sprint swimming performance and in-water forces. Methods: Eleven competitive adult male swimmers (50-m front crawl World Aquatics points: 488 [66], performance level 4) performed 1 experimental session. The L-V relationship variables (L-0 [ie, maximal theoretical load at 0 velocity]; v(0) [ie, maximal theoretical velocity at 0 load], and A(line) [ie, area under the L-V relationship]) and maximal mechanical maintenance capacity were assessed at the beginning of the session. Afterward, sprint swimming performance and in-water force production were tested through a 50-m front-crawl all-out trial and 15-s fully-tethered swimming, respectively. Results: Only v(0) presented high positive associations with 50-m time and swimming kinematics (r > .532; P < .046). The L-0, v(0), and A(line) showed very high positive associations with the in-water forces during tethered swimming (r > .523; P < .049). However, the ability to maintain maximal mechanical performance, assessed by the mean velocity decline during the prone bench pull, was only significantly correlated with stroke rate (r= -.647; P = .016) and stroke index (r= .614; P = .022). Conclusions: These findings indicate that maximal neuromuscular capacities, especially v(0), have a stronger correlation with swimming performance and in-water force production than the ability to maintain maximal mechanical performance in level 4 swimmers.