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Total Expired Non‐Metabolic VCO 2 and VCO 2 Recovery Kinetics as Predictors of Performance Fatigability During Exercise
Author(s) -
Wooten Liana C,
Aldhahi Monira I,
Keyser Randall E
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.lb436
Subject(s) - anaerobic exercise , kinetics , zoology , chemistry , cardiology , oxidative phosphorylation , medicine , endocrinology , physical therapy , biochemistry , biology , physics , quantum mechanics
Purpose The severity of performance fatigability (PF) and the capacity to recover from activity are each profoundly influenced by skeletal muscle energetics, specifically the ability to buffer fatigue‐inducing ions produced as a result of anaerobic metabolism. The mechanisms responsible for buffering these ions results in the production of non‐metabolic carbon dioxide (CO 2 ) that can be measured as expired CO 2 (VCO 2 ) during cardiopulmonary exercise testing (CPET). Yet, the relationships between PF and both total expired non‐metabolic (NMVCO 2 ) and the capacity to recover from activity have yet to be investigated. Methods 7 healthy subjects (30.71 ± 5.12 years) completed both a maximal and submaximal CPET on separate days, each followed by a 10‐minute recovery and 10‐minute walk test. Oxygen consumption (VO 2 ) and VCO 2 on and off‐kinetics (transition constant‐Kt and oxidative response index‐ORI), NMVCO 2 , and PF severity scores were measured. Data were analyzed using Pearson's correlations and regression analyses. Statistical significance was set at p<0.05. Results NMVCO 2 accumulation and VCO 2 off‐kinetic ORI accounted for 93% of the variance of PF severity scores (r 2 = 0.932; p = 0.012). Measures of VCO 2 off‐kinetics following both maximal (ORI r 2 = 0.932, p < 0.001; Kt r 2 = 0.919, p < 0.001) and submaximal (ORI r 2 = 0.928, p < 0.001; Kt r 2 = 0.955, p < 0.001 ) CPET and NMVCO 2 (r 2 = 0.614, p = 0.0371) were better predictors of PF than traditional measures of VO 2 (VO 2 peak r 2 = 0.388, p = 0.135; AT‐VO 2 r 2 = 0.297, p = 0.206). Conclusion Previous studies investigating relationships between cardiopulmonary variables and PF have traditionally utilized measures of VO 2 . The current study demonstrates that measures of VCO 2 may be more predictive of PF and its clinical manifestations. Furthermore, these measures were able to better predict PF even following submaximal testing presenting a less strenuous clinical measure of PF for those populations in which maximal exercise testing may be contraindicated. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .