Objectives: Skeletal muscle architecture (SMA) defines the mechanical limits of force production. However, its associations with force–time strategy under externally loaded conditions have received little research attention. This exploratory study examined associations between vastus lateralis (VL) and lateral gastrocnemius (LG) architecture and force–time strategy, jump-height retention, and stretch–shortening cycle (SSC) transfer-efficiency in collegiate basketball players. Methods: Seventeen collegiate male basketball players completed B-mode ultrasonographic assessment of VL and LG architecture, including muscle thickness, pennation angle (PA), and fascicle length. Athletes performed the squat jump (SJ), loaded squat jump (LSJ), countermovement jump (CMJ), and loaded countermovement jump (LCMJ) on force platforms, with a 20 kg external load applied for loaded conditions. Loaded retention, defined as the percentage of jump height preserved under load, was proposed as a unified construct. Pearson’s correlations were calculated, with Benjamini–Hochberg false discovery rate (FDR) corrections applied within predefined functional groups and pooled across morphology-sensitive correlations. Results: LG PA showed a large negative association with LCMJ rate of force development (r = −0.68 [−0.87, −0.30]) and a large positive association with LCMJ time to peak force (r = 0.68 [0.29, 0.87]), both surviving within-group FDR correction. VL PA was associated with eccentric acceleration time and concentric time across jump conditions (r = 0.52 to 0.61), interpreted as exploratory. Transfer-efficiency indices showed no significant associations with SMA, except for the LCMJ/LSJ concentric time ratio, which showed a moderate negative association with LG PA (r = −0.49 [−0.79, −0.01]). Conclusions: Resting muscle architecture was associated with the temporal and rate characteristics of force expression under load, rather than with the gross preservation of jump height. Integrating architectural assessment with loaded force–time profiling warrants further investigation as a means of characterizing individual force-development strategies.

Background: Vertical jump force–time strategy describes how force is organized in time. This strategy provides performance-relevant information that jump height alone does not capture in basketball players. Arm swing and external load are opposing conditions rarely imposed on the same athletes. However, little is known about how they reorganize jump strategy, or whether force production capacity is associated with the response. Methods: A within-participant, repeated-measures design was used. Seventeen collegiate male basketball players performed the countermovement jump (CMJ), the arm-swing countermovement jump (CMJA), and the 20 kg loaded countermovement jump (LCMJ) on force platforms in a fixed order within one session. The isometric mid-thigh pull provided relative peak force and the rate of force development (RFD₂₅₀). Vastus lateralis and lateral gastrocnemius architecture were assessed by ultrasonography. Linear mixed-effects models examined condition effects and capacity associations, with a condition-mean sensitivity analysis. Results: Relative to CMJ, CMJA increased jump height and prolonged contact and concentric times. In contrast, LCMJ reduced jump height and increased mean concentric force. No significant overall condition effect was found for gross peak force, and equivalence was not established. Relative isometric peak force was not significantly associated with jump height. The trial-level CMJA-by-RFD₂₅₀ interaction was significant, but the corresponding interaction was not significant in the condition-mean model. No architecture–RFD₂₅₀ correlation remained significant after correction for multiple comparisons. Conclusions: In this exploratory fixed-order design, the arm-swing and loaded conditions were associated with divergent force–time responses. Evidence for an overall condition effect on gross peak force was inconclusive, and the capacity associations require confirmation in larger, counterbalanced samples.

Background: Paired-set (PS) resistance exercise is widely used to increase training density; however, evidence-based guidance remains limited due to heterogeneous exercise sequences and rest configurations. This systematic review aimed to synthesize acute mechanical, training-efficiency, and perceptual responses across distinct PS configurations compared with traditional sets (TSs) in young resistance-trained adults. Methods: Eight databases were searched through 5 August 2026, for acute randomized crossover/parallel trials. PS protocols were categorized into PS-A (alternating exercises with preserved TS rest after each exercise), PS-B (interleaved exercises during recovery), and PS-C (modified post-pair rest). Study-level means and unstandardized percentage differences for volume load (VL), completed repetitions, training efficiency (VL accumulated per unit of time), and rating of perceived exertion (RPE) were synthesized descriptively. Results: Fifteen reports representing 14 studies (223 participants) were included, and all exhibited “some concerns” according to RoB 2. PS-A consistently elicited higher work-output point estimates (VL: 7.9–27.2%; repetitions: 6.3–26.7% vs. TS) with negligible changes in session duration. PS-B consistently reduced session duration by 44.8–50.0%, though repetitions and VL were often compromised depending on the exercise. PS-C responses were configuration-dependent; matched post-pair rest (PS-C_MPR) decreased duration (39.7–46.9%) with variable VL (−8.2% to +30.1%) and higher RPE, whereas extended rest (PS-C_EPR) showed distinct protocol-specific trade-offs between volume retention and training efficiency. Conclusions: Based on acute trials in young trained populations, PS configurations should be selected by session priority (PS-A for work capacity, PS-B for time constraints, PS-C for versatility). Given the consistent “some concerns” regarding risk of bias, these practical recommendations warrant caution.