Physical Demands and Acute Neuromuscular Responses Across a Single-Day 3 × 3 Male Basketball Tournament

Background: This study examined external intensity and acute neuromuscular responses across multiple games played during a single-day official 3 × 3 basketball tournament. Methods: Twelve male players (Tier 2–3; age: 24.7 ± 4.5 years; height: 186.4 ± 8.5 cm; body mass: 86.5 ± 13.0 kg) were monitored with microsensors (Movement Intensity (MI), while countermovement jump (CMJ) variables—jump height (JH); time to takeoff (TTTO); and Modified Reactive Strength Index (RSI_mod)—were obtained before the start of the tournament and after each game. Linear mixed models examined differences in MI and CMJ variables across tournament phases. Additionally, the smallest worthwhile change (SWC) calculations were applied to all comparisons. Results: No statistical differences were found across tournament stages for MI (p = 0.466), JH (p = 0.762), TTTO (p = 0.990), or RSI_mod (p = 0.951). SWC comparisons showed that MI was higher in GG1 than GG2, GG3, and QF; higher in GG2 than GG3; and lower in G3 than QF and SF. Regarding JH, the post-QF value was higher than the baseline and post-GG2. For TTTO, post-QF was higher than post-GG1. RSI_mod post-GG2 was lower than post-GG3 and post-SF. Conclusions: While no significant changes were observed, MI showed a practically meaningful decline in GG3 and recovery in QF, while RSI_mod initially declined before improving post-SF. These findings highlight the importance of pacing and recovery strategies in 3 × 3 basketball tournaments.