Endurance Training and V[spacing dot above]O2max: Role of Maximal Cardiac Output and Oxygen Extraction.

• Autores: David Montero, Carsten Lundby, Candela Diaz Canestro
• Localización: Medicine & Science in Sports & exercise: Official Journal of the American College of Sports Medicine, ISSN 0195-9131, Vol. 47, Nº. 10, 2015, págs. 2024-2033
• Idioma: inglés
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• Resumen

  • AB Purpose: Although endurance training (ET) commonly augments maximal oxygen consumption (V[spacing dot above]O2max), it remains unclear whether such increase is associated with that of maximal cardiac output (Qmax) alone or along with arteriovenous oxygen difference (a-V[spacing dot above]O2diff). Herein, we sought to systematically review and determine the effects of ET on V[spacing dot above]O2max, Qmax, and a-V[spacing dot above]O2diff at maximal exercise, and on their associations, in healthy young subjects. Methods: We conducted a systematic search of MEDLINE, Scopus, and Web of Science (from their inception until September 2014) for articles assessing the effects of ET lasting >=3 wk on V[spacing dot above]O2max and Qmax and/or a-V[spacing dot above]O2diff at maximal exercise in healthy young adults (mean age <40 yr). Meta-analyses were performed to determine standardized mean differences (SMD) in V[spacing dot above]O2max, Qmax, and a-V[spacing dot above]O2diff at maximal exercise between posttraining and pretraining measurements. Subgroup and meta-regression analyses were used to evaluate associations among SMD and potential moderating factors. Results: Thirteen studies were included after systematic review, comprising a total of 130 untrained or moderately trained healthy young subjects (mean age, 22-28 yr). Duration of ET programs ranged from 5 to 12.9 wk. After data pooling, V[spacing dot above]O2max (SMD = 0.75, P < 0.0001) and Qmax (SMD = 0.64, P < 0.0001), but not a-V[spacing dot above]O2diff at maximal exercise (SMD = 0.21, P = 0.23), were increased after ET. No significant heterogeneity was detected. With meta-regression, the SMD in Qmax was positively associated with the SMD in V[spacing dot above]O2max (B = 0.91, P = 0.007). The SMD in a-V[spacing dot above]O2diff at maximal exercise was not associated with the SMD in V[spacing dot above]O2max (B = 0.20, P = 0.40). Conclusions: Based on a relatively small number of studies, improvement in V[spacing dot above]O2max following 5-13 wk of ET is associated with increase in Qmax, but not in a-V[spacing dot above]O2diff, in previously untrained to moderately trained healthy young individuals