INSPIRATORY MUSCLE TRAINING IN TRAINED ATHLETES: A META-ANALYSIS. Adam Lipman*; James Spencer; Jon Ulrich; Paul Canavan; Lawrence P. Cahalin Physical Therapy, Northeastern University, Boston, MA PURPOSE: To perform a meta-analysis of inspiratory muscle training (IMT) in trained athletes. BACKGROUNDS/SIGNIFICANCE: IMT has been proposed as a method to enhance athletic performance. The basic assumption is that improved inspiratory muscle strength and endurance (IMS and IME, respectively) may improve cardiovascular and pulmonary function resulting in greater available blood flow to exercising muscles with greater exercise tolerance (ET) and peak oxygen consumption (pVO2). However, no clear consensus regarding IMT in trained athletes exists. SUBJECTS: Not Applicable METHODS AND MATERIALS: A Medline search was performed for published peer reviewed studies of IMT in athletes. Inclusion criteria included quasi- experimental and experimental studies of IMT in trained athletes participating in any sport. ANALYSES: Studies meeting inclusion criteria underwent (1) a critical review of quality using 16 criteria and (2) calculation of individual study and overall summary effect sizes (via Hedges's g). RESULTS: A total of 24 studies were identified of which 11 met inclusion criteria and demonstrated adequate quality. However, complete data was available in only 8 of the studies. Three of the 8 studies used in the meta-analysis involved bicyclists, three involved a variety of athletes, one involved rowers, and one involved runners. Individual study effect sizes of IMS, IME, ET, pVO2, and lactate levels (LL) were moderate to high and the overall summary effect sizes of IMS, IME, ET, pVO2, and LL were 1.77, 1.16, 8.39, 0.24, and 0.81, respectively (p<0.0001 for all variables). CONCLUSIONS: Although the literature investigating the effects of IMT in athletes is limited, the overall effect sizes strongly suggest that IMT is an important tool to improve athletic performance in trained athletes. FUNDING SOURCE: Not Applicable KEYWORDS: athletes, inspiratory muscle training Copyright 2009 by the American Physical Therapy Association. Requests for reprints should be directed to the corresponding author of the article. Educators, students, and other academic customers may receive permission to reprint copyrighted material from Physical Therapy (ISSN 1538-6724) by contacting the Copyright Clearance Center Inc, 222 Rosewood Dr, Danvers, MA 01923. Other types of customers who want permission to reprint should contact the APTA Editorial Office, Attn: Physical Therapy.