A scoping review of the effect of chronic stretch training on sleep quality in people with sleep disorders.

Purpose: The widespread and health-detrimental sleep disorders have resulted in stretching exercises being investigated as a non-drug solution for enhanced sleep quality. However, a comprehensive understanding of the impact of stretching exercises on individuals with sleep disorders is lacking.

Methods: This scoping review systematically maps the existing literature and identifies research gaps on the impact of stretching exercises on sleep quality in individuals with sleep disorders.

Results: Sixteen eligible studies were included, where the weighted mean changes indicate a positive trend in sleep quality improvement, ranging from trivial to very large magnitudes. However, concerning the individual study results only 5 out of 16 studies reported significant improvements. Notable enhancements include a small 1.22% overall sleep quality improvement, a large 6.51% reduction in insomnia severity, a large 8.88% increase in sleep efficiency, a moderate 4.36% decrease in sleep onset latency, a large 8.27% decrease in wake after sleep onset, and a very large 14.70% improvement in total sleep time. Trivial changes are noted in sleep duration (0.58%), sleep disturbance reduction (0.07%), and daytime dysfunction reduction (0.19%). Likely mechanisms for the improvement of sleep include autonomic nervous system modulation, muscle tension relief, cortisol regulation, enhanced blood circulation, and psychological benefits such as stress reduction and mood enhancement.

Conclusion: There is little evidence that stretching exercises positively impact sleep quality in individuals with sleep disorders. Additionally, further research is vital for designing optimal protocols, understanding of the long-term effects, and clarification of the mechanisms.