title: Effect of linear polarized near-infrared light irradiation and light exercise on muscle performance.
abstract: This study aimed to determine the effect of active warm-up by local muscle light exercise and passive warm-up by polarized light irradiation on skin and muscle temperatures and forearm muscle performance (muscle strength, power, endurance, and controlled force-exertion). Ten healthy males performed various grip tests before and after active (local muscle light exercise) and passive (linear polarized near-infrared light irradiation) warm-ups. An active warm-up involved intermittent gripping exercise (contraction: 1 second and relaxation: 1 second) for 10 minutes using a sponge. A passive warm-up consisted of polarized light irradiation to the forearm (superficial digital flexor) for 10 minutes (irradiation: 5 seconds and rest: 1 second). Skin and muscle temperatures were measured during both warm-ups. Skin and muscle temperatures increased significantly after 5 minutes of local muscle light exercise and after 10 minutes of polarized light irradiation. Temperatures were significantly higher after 6 minutes of local muscle light exercise than after 6 minutes of polarized light irradiation. There were no significant differences of muscle strength, power, and controlled force-exertion before and after either warm-up. Average force outputs in all conditions significantly decreased with exertion time, and at 30, 60, 90, and 120 seconds they were higher in both warm-up conditions than in the non-warm-up condition. In conclusion, both warm-ups may contribute to improve muscle endurance performance in the decreasing force phase.
authors.affiliation: Graduate School of Natural Science & Technology, Kanazawa University.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Demura
authors.forename: Shinichi
authors.initials: S
authors.lastname: Demura
authors.forename: Hiroki
authors.initials: H
authors.lastname: Aoki
authors.forename: Yuu
authors.initials: Y
authors.lastname: Uchida
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yamaji
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D054874:Athletic Performance; D015444:Exercise / Q000502:physiology*; D005542:Forearm / Q000502:physiology; D006801:Humans; D007259:Infrared Rays; D008297:Male; D053580:Muscle Strength / Q000502:physiology* / Q000528:radiation effects*; D018482:Muscle, Skeletal / Q000502:physiology*; D010807:Physical Endurance / Q000528:radiation effects*; D012881:Skin Temperature; D055815:Young Adult