W Daly1, C Seegers1, S Timmerman1, A C Hackney1. 1. Endocrine Section - Applied Physiology Laboratory, University of North Carolina, Chapel Hill, North Carolina, USA.
Abstract
INTRODUCTION: Strenuous exercise provokes increases in circulating cortisol levels. When the peak cortisol response to exercise occurs is a point of contention, as some research suggests the peak response coincides with the end of exercise while other indicate it is delayed and occurs during recovery. AIM OF THE STUDY: This study examined when peak cortisol levels occur in response to intensive, exhausting exercise of a prolonged nature. METHODS: Thirty-four healthy male subjects ran on a treadmill until volitional exhaustion. Blood specimens were analyzed for cortisol levels immediately at the end of exercise and at 30, 60, and 90 minutes into recovery. RESULTS: A significantly greater number (25/34; i.e., 73.5%) of the peak cortisol responses occurred during the recovery period (at 30 - 90 minutes) after the subjects reached volitional exhaustion and had stopped exercising. CONCLUSION: The findings suggest that if researchers are interested in assessing the peak cortisol response to exhausting exercise they should continue blood sampling for approximately 1 hour into the recovery period.
INTRODUCTION: Strenuous exercise provokes increases in circulating cortisol levels. When the peak cortisol response to exercise occurs is a point of contention, as some research suggests the peak response coincides with the end of exercise while other indicate it is delayed and occurs during recovery. AIM OF THE STUDY: This study examined when peak cortisol levels occur in response to intensive, exhausting exercise of a prolonged nature. METHODS: Thirty-four healthy male subjects ran on a treadmill until volitional exhaustion. Blood specimens were analyzed for cortisol levels immediately at the end of exercise and at 30, 60, and 90 minutes into recovery. RESULTS: A significantly greater number (25/34; i.e., 73.5%) of the peak cortisol responses occurred during the recovery period (at 30 - 90 minutes) after the subjects reached volitional exhaustion and had stopped exercising. CONCLUSION: The findings suggest that if researchers are interested in assessing the peak cortisol response to exhausting exercise they should continue blood sampling for approximately 1 hour into the recovery period.
Authors: D C Nieman; L S Berk; M Simpson-Westerberg; K Arabatzis; S Youngberg; S A Tan; J W Lee; W C Eby Journal: Int J Sports Med Date: 1989-10 Impact factor: 3.118