title: LED therapy or cryotherapy between exercise intervals in Wistar rats: anti-inflammatory and ergogenic effects.
abstract: The aim of this study was to test, between two bouts of exercise, the effects of light-emitting diode (LED) therapy and cryotherapy regarding muscle damage, inflammation, and performance. Male Wistar rats were allocated in four groups: control, passive recovery (PR), cryotherapy (Cryo), and LED therapy. The animals were submitted to 45 min of swimming exercise followed by 25 min of recovery and then a second bout of either 45 min of exercise (muscle damage analysis) or time to exhaustion (performance). During the rest intervals, the rats were kept in passive rest (PR), submitted to cold water immersion (10 min, 10 °C) or LED therapy (940 nm, 4 J/cm(2)) of the gastrocnemius muscle. Blood samples were collected to analyze creatine kinase activity (CK), C-reactive protein (CRP), and leukocyte counts. The soleus muscles were evaluated histologically. Time to exhaustion was recorded during the second bout of exercise. After a second bout of 45 min, the results demonstrated leukocytosis in the PR and Cryo groups. Neutrophil counts were increased in all test groups. CK levels were increased in the Cryo group. CRP was increased in PR animals. The PR group presented a high frequency of necrosis, but the LED group had fewer necrotic areas. Edema formation was prevented, and fewer areas of inflammatory cells were observed in the LED group. The time to exhaustion was greater in both the LED and Cryo groups, without differences in CK levels. CRP was decreased in LED animals. We conclude that LED therapy and cryotherapy can improve performance, although LED therapy is more efficient in preventing muscle damage and local and systemic inflammation.
authors.affiliation: Department of Physical Education, Universidade Estadual de Londrina, Londrina, Paraná, Brazil.
authors.forename: Vanessa Batista
authors.initials: VB
authors.lastname: da Costa Santos
authors.forename: Solange
authors.initials: S
authors.lastname: de Paula Ramos
authors.forename: Vinícius Flávio
authors.initials: VF
authors.lastname: Milanez
authors.forename: Julio Cesar Molina
authors.initials: JC
authors.lastname: Corrêa
authors.forename: Rubens Igor
authors.initials: RI
authors.lastname: de Andrade Alves
authors.forename: Ivan Frederico Lupiano
authors.initials: IF
authors.lastname: Dias
authors.forename: Fábio Yuzo
authors.initials: FY
authors.lastname: Nakamura
mesh_terms: D000818:Animals; D002097:C-Reactive Protein / Q000378:metabolism; D017679:Cryotherapy / Q000379:methods*; D007249:Inflammation / Q000517:prevention & control / Q000628:therapy*; D054023:Lasers, Semiconductor / Q000627:therapeutic use*; D007958:Leukocyte Count; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology / Q000528:radiation effects; D010805:Physical Conditioning, Animal; D051381:Rats; D017208:Rats, Wistar; D013550:Swimming
chemical_list: D002097:C-Reactive Protein