The Impact of Acute Pain on Sleep Parameters in the Insomnia Population and Healthy Controls

This study investigates how acute exercise-induced muscular pain affects sleep quality and sleep architecture in people with insomnia compared to healthy sleepers. Sleep disturbances and pain often influence each other, creating a negative cycle; however, it remains unclear how acute muscle pain-such as delayed-onset muscle soreness (DOMS) after strenuous exercise-alters continuous sleep parameters and pain sensitivity differently in clinical insomnia populations versus healthy controls. Participants will be divided into two groups: individuals with clinical insomnia and age- and sex-matched healthy sleepers. Both groups will undergo a standardised exercise protocol designed to safely induce temporary, acute muscular soreness (DOMS). Objective sleep parameters (measured via wrist actigraphy) and subjective sleep parameters (measured via sleep diaries), will be monitored before and after the pain induction. The primary goal is to determine whether individuals with insomnia experience greater sleep disruption and altered pain recovery trajectories following an acute painful event compared to healthy individuals.

Inclusion Criteria: * Adults aged 18 to 60 years * Right-hand and right-foot dominant Exclusion Criteria: * History of any chronic musculoskeletal pain or presence of existing pain during recruitment * Previous major injuries or surgery involving the lower limbs * Sleep disorders other than insomnia * Clinically diagnosed psychiatric disorders * Contraindications to vigorous exercise identified through the physical activity readiness questionnaire (PAR-Q) * Work night shifts or rotating shift schedules * Pregnant