Prevalence of Exercise-Induced Arterial Hypoxemia in Distance Runners at Sea Level.
Purpose: It has been reported that ~50% of endurance-trained men demonstrate exercise induced arterial oxyhemoglobin hypoxemia (EIAH) during heavy exercise. However, this often-cited prevalence rate comes from a single study using a cohort of 25 highly trained men who completed maximal cycle ergometry. As arterial oxyhemoglobin saturation (SpO2) during maximal exercise is reported to be significantly lower during treadmill vs. cycle ergometry in the same subjects, we hypothesized that the prevalence of EIAH would be greater than previously reported (and commonly referenced) in a larger cohort of highly endurance-trained men during maximal treadmill running.
Methods: Data from 124 highly trained male distance runners (VO2max range 60.3 - 84.7 mL[middle dot]kg-1[middle dot]min-1) were retrospectively examined from previously published studies completed in the Indiana University Human Performance Laboratory. Subjects completed a constant speed, progressive grade treadmill exercise test to volitional exhaustion, and arterial oxyhemoglobin saturation (SaO2ear) in all subjects was estimated using the same oximeter (Hewlett Packard 47201A).
Results: Utilizing similar inclusion criteria as previously published for highly trained (VO2max > 68 mL[middle dot]kg-1[middle dot]min-1) and for EIAH (SaO2ear <= 91%), 55 of 79 subjects (70%) exhibited exercise induced arterial desaturation. Across all 124 subjects, 104 (84%) demonstrated at least moderate EIAH (SaO2ear <= 93%) during maximal treadmill exercise. SaO2ear was significantly, yet weakly correlated with VE/VO2 (p < 0.01; r = 0.28) and VE/VCO2 (p < 0.001; r = 0.33) but not with VO2max.
Conclusion: These results indicate that the prevalence of EIAH in highly trained men during maximal treadmill exercise at sea level is greater than has been previously suggested, with exercise mode perhaps playing a factor in the number of athletes who experience EIAH.
(C) 2016 American College of Sports Medicine
Autor / Fonte:Keren Constantini, David A Tanner, Timothy P Gavin, Craig A Harms, Joel M Stager, Robert F Chapman Medicine and Science in Sports and Exercise 2016 December 22