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Austin, K G.1; Daigle, K1; Cowman, J1; Chelland, S1; Haymes, E M. FACSM1; Patterson, P1

Medicine & Science in Sports & Exercise: May 2003 - Volume 35 - Issue 5 - p S193
D-14Q Free Communication/Poster Validity: Instrumentation and Equations

1Florida State University, Tallahassee, FL and San Diego State University, San Diego, CA

Near-infrared spectroscopy is a technological tool that is currently used to assess changes in oxyhemoglobin and therefore the oxygen saturation of the muscle during exercise and recovery from exercise. Oxygen uptake, blood lactate levels and heart rate are reliable methods for determining intensity of exercise.

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The purpose of this study was to assess the reliability of near-infrared spectroscopy in determining muscle oxygen saturation in the vastus lateralis during cycling and the gastrocnemius during running for exercise intensities at lactate threshold (LT) and maximal effort (VO2max).

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Twenty-three runners and twenty-one cyclists completed two incremental tests (3 minute stages) to maximal exhaustion 5 to 7 days apart. Oxygen consumption (VO2), heart rate (HR), blood lactate (HLa), and muscle oxygen saturation (StO2) are reported for LT and VO2max. Test-retest reliability was determined from an intraclass correlation coefficient (R; 95%CI) obtained from a one-way analysis of variance. The root mean square error (RMSE) was also reported.

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Reliability of muscle StO2 for the gastrocnemious at lactate threshold was r = .87 (95% CI = .72 to .94; RMSE = 5.34) and at maximal effort was r = .88 (95% CI = .73 to .94; RMSE = 5.00). Reliability of muscle StO2 for the vastus lateralis at lactate threshold was r = .94 (95%CI = .87 to .98; RMSE = 4.09) and at maximal effort was r = .99 (95%CI = .98 to .99; RMSE = 1.61).

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Reliability results indicate that near-infrared spectroscopy is a reliable instrument with standard errors ranging from 1.6% to 5.3%. Near-infrared spectroscopy appears to be an additional tool that can be utilized when examining exercise intensity. Supported by Hutchinson Technology, Inc., Hutchinson, Minnesota

©2003The American College of Sports Medicine