Inertial measurement units (IMUs) have been used increasingly to characterize long-track speed skating. We aimed to estimate the accuracy of IMUs for use in phase identification of long-track speed skating. Twelve healthy competitive athletes on a university long-track speed skating team participated in this study. Foot pressure, acceleration and knee joint angle were recorded during a 1000-m speed skating trial using the foot pressure system and IMUs. The foot contact and foot-off timing were identified using three methods (kinetic, acceleration and integrated detection) and the stance time was also calculated. Kinetic detection was used as the gold standard measure. Repeated analysis of variance, intra-class coefficients (ICCs) and Bland-Altman plots were used to estimate the extent of agreement between the detection methods. The stance time computed using the acceleration and integrated detection methods did not differ by more than 3.6% from the gold standard measure. The ICCs ranged between 0.657 and 0.927 for the acceleration detection method and 0.700 and 0.948 for the integrated detection method. The limits of agreement were between 90.1% and 96.1% for the average stance time. Phase identification using acceleration and integrated detection methods is valid for evaluating the kinematic characteristics during long-track speed skating.

Background/Objectives: This study aimed to provide preliminary normative data on intersegmental coordination patterns during heel rises at different knee joint positions and across various phases and periods. Methods: Twelve 21-year-old university students from the same cohort performed heel rises in knee-extended and knee-flexed conditions. Shank and foot kinematics were recorded using the VICON Oxford Foot Model, and intersegmental coordination was analyzed using a modified vector coding technique. Results: The results showed that coordination patterns varied significantly between the ascending and descending phases and across the early, middle, and late periods. In the early ascending phase, knee extension exhibited in-phase coordination (shank external rotation with hindfoot inversion), resembling propulsion-related coordination in gait, whereas knee flexion displayed greater anti-phase coordination between hindfoot plantar flexion and forefoot dorsiflexion. The middle and late periods demonstrated heel-rise-specific patterns, with coordination shifting from proximal to distal dominance. Knee flexion altered the coordination between the shank and hindfoot and between the hindfoot and forefoot in the sagittal plane compared to that during knee extension. Conclusions: These findings suggest that the knee position influences intersegmental coordination during heel rises, and the present results provide reference values that can enable future diagnostic validation and comparative studies in pathological populations.

Anxiety is a common psychological challenge among athletes, particularly in response to intense training sessions. This randomized crossover study investigated the immediate effects of a single session of focused attention meditation on anxiety, autonomic responses, and performance during high-intensity intermittent training (HIIT) in twenty-six university-level speed skaters. Participants completed three pre-exercise interventions (focused attention meditation, controlled breathing, and random thinking) on separate occasions in a randomized order. Following each intervention, participants performed a leg cycling-based HIIT protocol consisting of 20 s of maximal effort work followed by 10 s of passive rest, repeated for 8 sets using a cycling ergometer. State anxiety was assessed using the State–Trait Anxiety Inventory, and mood disturbance was evaluated using the Profile of Mood States. Autonomic and physiological responses were assessed via heart rate variability (coefficient of variation), oxygen uptake, and power output, measured before and after the intervention and the HIIT bout. Focused attention meditation significantly reduced state anxiety compared with random thinking (ΔSTAI: −5.0 [6.0] vs. −1.0 [4.3]; p < 0.05, effect size = 0.527), whereas controlled breathing primarily influenced heart rate variability (CV: 0.10 [0.11] vs. 0.07 [0.03]; p = 0.041, effect size = 0.736). No significant differences were observed among conditions in mean power output or fatigue index during HIIT. These findings suggest that single-session focused attention meditation may serve as a practical pre-exercise strategy for an immediate reduction in state anxiety, without compromising subsequent high-intensity exercise performance.