Sleep quality is essential for maintaining physical health and psychological resilience. Because sleepwear remains in direct contact with the skin throughout the night, it may affect thermoregulation and comfort and, thereby, influence sleep. This randomized two-period, two-sequence crossover study investigated whether sleepwear infused with nanodiamond and nanoplatinum particles (DPV576) could improve sleep quality and promote fatigue recovery under free-living conditions. Fourteen healthy men (23.9 ± 1.7 years) wore DPV576 sleepwear and visually indistinguishable standard polyester sleepwear for one week each, separated by a one-week washout. Sleep was assessed using a wearable ECG-based actigraphy device; trained researchers additionally performed manual rescoring to verify automated outputs, including independent determination of sleep onset latency. Subjective sleep was assessed daily using the Sleep Quality Index of Daily Sleep and a visual analog scale; exploratory outcomes included voice-derived biomarkers and pre-/post-sleep grip strength. In manual rescoring, DPV576 was associated with higher sleep efficiency (93.0 ± 0.9% vs. 89.5 ± 1.5%, p < 0.05), fewer awakenings (8.4 ± 1.3 vs. 10.7 ± 1.4, p < 0.01), and shorter wake after sleep onset (30.4 ± 4.7 vs. 41.6 ± 6.0 min, p < 0.01), whereas total sleep time did not differ significantly (p = 0.096). These findings suggest that one-week use of DPV576 sleepwear may improve wearable ECG-derived sleep consolidation in young men, supporting a nonpharmacological wearable strategy to enhance sleep efficiency in everyday settings.
Keywords: actigraphy; crossover trial; functional textile; sleep efficiency; sleepwear; thermoregulation; wake after sleep onset; wearable ECG.