by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited. Copyright @ 2010 Ellagitannin Consumption Improves Strength Recovery 2–3 d after Eccentric Exercise JUSTIN R. TROMBOLD 1 , JILL N. BARNES 2 , LEAH CRITCHLEY 1 , and EDWARD F. COYLE 1 1 Human Performance Laboratory, Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX; and 2 Cardiovascular Aging Research Laboratory, Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX ABSTRACT TROMBOLD, J. R., J. N. BARNES, L. CRITCHLEY, and E. F. COYLE. Ellagitannin Consumption Improves Strength Recovery 2–3 d after Eccentric Exercise. Med. Sci. Sports Exerc., Vol. 42, No. 3, pp. 493–498, 2010. Purpose: Dietary supplementation with poly- phenols, particularly ellagitannins, may attenuate the muscular damage experienced after eccentric exercise, producing delayed-onset muscle soreness. The purpose of this study was to determine whether ellagitannin supplementation from Wonderful variety pome- granate extract (POMx) improved recovery of skeletal muscle strength after eccentric exercise. Methods: Recreationally active males were randomized into a crossover design with either pomegranate extract (POMx) or placebo (PLA), each given during a period of 9 d. To produce delayed-onset muscle soreness, subjects performed two sets of 20 maximal eccentric elbow flexion exercises with one arm. Maximal isometric elbow flexion strength and muscle soreness as well as serum measures of creatine kinase, myoglobin, interleukin 6, and C-reactive protein were made at baseline and 2, 24, 48, 72, and 96 h after exercise. Results: With both treatments, strength was similarly reduced 2 h after exercise (i.e., 72% of baseline), and recovery of strength was incomplete after 96 h (i.e., 91% of baseline). However, strength was significantly higher in POMx compared with that in PLA at 48 h (85.4% T 2.5% and 78.3% T 2.6%, P = 0.01) and 72 h (88.9% T 2.0% and 84.0% T 2.0%, P = 0.009) after exercise. Serum markers of inflammation and muscle damage did not provide insight regarding possible mechanisms. Conclusions: Supplementation with ellagitannins from pomegranate extract signifi- cantly improves recovery of isometric strength 2–3 d after a damaging eccentric exercise. Key Words: POLYPHENOLS, ISOMETRIC STRENGTH, DELAYED-ONSET MUSCLE SORENESS, INFLAMMATION P olyphenols derived primarily from fruits have been observed to improve function of people placed under stress because of cellular insult from colon cancer (1), rheumatoid arthritis (29), and cardiovascular disease (2,3,14,16,20). Eccentric exercise in people produ- ces delayed-onset muscle soreness (DOMS) and provides a good model for evaluating the functional significance of polyphenol supplementation for enhancing some aspects of in vivo tissue recovery. The acute muscle damage from eccentric exercise can cause local inflammation (22,27), oxidative stress (33), and release of Ca 2+ -activated prote- ases (4,6,21). These processes are generally similar to pathological types of cellular damage. Several days are re- quired to recover from DOMS, and thus, careful measures of strength can be used to describe the time course of re- covery of function. Recently, polyphenol supplementation from tart cherries has been reported to accelerate recovery of strength after performing eccentric exercise (12). To our knowledge, no other study using humans has identified a treatment that is effective at improving recovery of muscle strength with DOMS. The mechanisms mediating the biological benefits of polyphenol supplementation from fruit are not clear but may be linked to the attenuation of oxidative stress and inflammation (1,18,20). Supplementation with vitamin E or C has no influence on soreness or strength (5,11) and NSAID supplementation reduces soreness but does not im- prove strength (15). Ingestion of various mixtures of to- copherols, docosahexaenoate, selenium, or flavanoids (i.e., quercetin and hesperetin) has been observed to reduce oxi- dative stress (17) or inflammation (26) after eccentric exercise, yet strength was not measured. It seems that no study in humans has shown that a nutritional supplement improves recovery of muscle function by reducing inflam- mation or oxidative stress. The purpose of this study was to determine in humans if polyphenol supplementation from ellagitannins in pome- granate extract improves recovery of muscle strength and soreness and attenuates markers of inflammation and Address for correspondence: Edward F. Coyle, Ph.D., FACSM, The University of Texas at Austin, One University Station, Bellmont Hall, Room 222K, Austin, TX 78712; E-mail: coyle@mail.utexas.edu. Submitted for publication February 2009. Accepted for publication July 2009. 0195-9131/10/4203-0493/0 MEDICINE & SCIENCE IN SPORTS & EXERCISE Ò Copyright Ó 2010 by the American College of Sports Medicine DOI: 10.1249/MSS.0b013e3181b64edd 493 BASIC SCIENCES