Association Between Alcohol Brief Intervention and Emergency Department and Inpatient Utilization Over 2 Years.

Physical activity’s health benefits are well-documented in the literature [,], yet many people struggle to maintain regular exercise due to discomfort or negative affective experiences [–]. A key factor influencing exercise adherence resides in how people feel during physical activity and how exercise alters affective responses (pleasure or displeasure) and perceived exertion (RPE) [–,,]. These psychological responses may be shaped not only by exercise intensity but also by kinematic adjustments, such as changes in stride frequency. Indeed, they are highly sensitive to the interplay between external exercise parameters (i.e., stride frequency or speed) and internal biological states. For instance, it was demonstrated that internal biological variations, including differences between the luteal and follicular phases in eumenorrheic women, can significantly impair affect and motivation during high-intensity exercise, even when physiological markers remain unchanged []. This finding underscores the importance of considering both physiological parameters and individual constraints (i.e., potential sex-specific biological variations) when examining behavioral and psychological responses to altered movement patterns. Humans naturally choose a walking stride frequency that minimizes energy cost, termed the preferred stride frequency (PSF) []. Stride frequency is primarily regulated by the central pattern generators (CPGs) [,]. Central pattern generators (CPGs) are neural circuits within the spinal cord that produce rhythmic motor patterns with minimal cortical input (central motor drive) [,]. While CPGs produce the basic locomotor rhythm, their function is continuously modulated by supraspinal input and somatosensory feedback, which become particularly important when the natural rhythm is disrupted [–]. Deviating from the PSF, whether by increasing or decreasing stride frequency, elevates energy cost in a U-shaped pattern [–]. Any departure from PSF is associated with increased heart rate and RPE []. While these physiological effects are well-documented, the impact on affective states, such as changes in pleasure or arousal, remains unclear. Imposed alterations in stride frequency may influence the conscious mental effort required to maintain neuromuscular drive in the limbs at a preferred walking speed. This, in turn, may affect perceived exertion and affective responses during exercise, as well as decision-making related to engaging in walking as parts of daily activities [,].