Postexercise Muscle Cooling Enhances Gene Expression of PGC-1> MOHAMMED IHSAN 1 , GREIG WATSON 2 , HUI CHENG CHOO 1 , PAUL LEWANDOWSKI 3 , ANNATERESA PAPAZZO 3 , DAVID CAMERON-SMITH 4 , and CHRIS R. ABBISS 1 1 Centre for Sports and Exercise Science Research, School of Exercise and Health Sciences, Edith Cowan University, Perth, AUSTRALIA; 2 School of Human Life Sciences, University of Tasmania, Launceston, AUSTRALIA; 3 School of Medicine, Deakin University, Melbourne, AUSTRALIA; and 4 Liggins Institute, University of Auckland, Auckland, NEW ZEALAND ABSTRACT IHSAN, M., G. WATSON, H. C. CHOO, P. LEWANDOWSKI, A. PAPAZZO, D. CAMERON-SMITH, AND C. R. ABBISS. Postexercise Muscle Cooling Enhances Gene Expression of PGC-1>. Med. Sci. Sports Exerc., Vol. 46, No. 10, pp. 1900–1907, 2014. Purpose: This study aimed to investigate the influence of localized muscle cooling on postexercise vascular, metabolic, and mitochondrial-related gene expression. Methods: Nine physically active males performed 30 min of continuous running at 70% of their maximal aerobic velocity, followed by intermittent running to exhaustion at 100% maximal aerobic velocity. After exercise, subjects immersed one leg in a cold water bath (10-C, COLD) to the level of their gluteal fold for 15 min. The contralateral leg remained outside the water bath and served as control (CON). Core body temperature was monitored throughout the experiment, whereas muscle biopsies and muscle temperature (T m ) measurements were obtained from the vastus lateralis before exercise (PRE), immediately postexercise (POST-EX, T m only), immediately after cooling, and 3 h postexercise (POST-3H). Results: Exercise significantly increased core body temperature (PRE, 37.1-C T 0.4-C vs POST-EX, 39.3-C T 0.5-C, P G 0.001) and T m in both CON (PRE, 33.9-C T 0.7-C vs POST-EX, 39.1-C T 0.5-C) and COLD legs (PRE, 34.2-C T 0.9-C vs POST-EX, 39.4-C T 0.3-C), respectively (P G 0.001). After cooling, T m was significantly lower in COLD (28.9-C T 2.3-C vs 37.0-C T 0.8-C, P G 0.001) whereas PGC-1> messenger RNA expression was significantly higher in COLD at POST-3H (P = 0.014). Significant time effects were evident for changes in vascular endothelial growth factor (P = 0.038) and neuronal nitric oxide synthase (P = 0.019) expression. However, no significant condition effects between COLD and CON were evident for changes in both vascular endothelial growth factor and neuronal nitric oxide synthase expressions. Con- clusions: These data indicate that an acute postexercise cooling intervention enhances the gene expression of PGC-1> and may therefore provide a valuable strategy to enhance exercise-induced mitochondrial biogenesis. Key Words: EXERCISE RECOVERY, MUSCLE AEROBIC ADAPTATIONS, COLD WATER IMMERSION, MITOCHONDRIAL BIOGENESIS, VASCULAR ENDOTHELIAL GROWTH FACTOR, NONSHIVERING THERMOGENESIS E ndurance training results in a broad range of impor- tant skeletal muscle adaptations that improve aero- bic capacity, including increased mitochondrial content (12) and capillary density (6) and improved conduit and microvascular function (17,34). Although the mechanisms underlying these adaptations are not completely understood, it is well accepted that the transcriptional coactivator per- oxisome proliferator-activated receptor gamma coactivator- 1> (PGC-1>) is a key regulator of mitochondrial biogenesis, and vascular and metabolic adaptations to exercise (45). Spe- cifically, PGC-1> has been shown to regulate the expression of the cellular glucose transporter 4 (GLUT4) and the angio- genic and arteriogenic signaling protein vascular endothelial growth factor (VEGF) (4,23). Expression of PGC-1> and sub- sequent downstream regulators seems to be influenced by nitric oxide (NO) (27). Indeed, in rodent and cell culture models, treatment with an NO synthase (NOS) inhibitor or NO donor has been shown to suppress or enhance the gene expression of VEGF and GLUT4, respectively (9,19). These results highlight NO and PGC-1> as principal regulators of the skeletal muscle mitochondrial, vascular, and metabolic adaptations to exercise. BASIC SCIENCES Address for correspondence: Mohammed Ihsan, B.Sc., Centre for Sports and Exercise Science Research, School of Exercise and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Perth, Western Australia, Australia; E-mail: m.abdullah@ecu.edu.au. Submitted for publication September 2013. Accepted for publication February 2014. Supplemental digital content is available for this article. Direct URL cita- tions appear in the printed text and are provided in the HTML and PDF versions of this article on the journal_s Web site (www.acsm-msse.org). 0195-9131/14/4610-1900/0 MEDICINE & SCIENCE IN SPORTS & EXERCISE Ò Copyright Ó 2014 by the American College of Sports Medicine DOI: 10.1249/MSS.0000000000000308 1900 Copyright © 2014 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.