Effect of Ischemic Preconditioning on Endurance Performance Does Not Surpass Placebo

Autor(es)

Sabino-Carvalho, Jeann L. ; Lopes, Thiago R. ; Obeid-Freitas, Tiago ; Ferreira, Thiago N. ; Succi, Jose E. ; Silva, Antonio C. ; Silva, Bruno M.

• Tipo de documento: Artigo Científico
• Fonte: MEDICINE AND SCIENCE IN SPORTS AND EXERCISE; v. 49, n. 1, p. 124-132, JAN 2017.
• Citações Web of Science: 25

Resumo

Purpose: Recent studies have reported ischemic preconditioning (IPC) can acutely improve endurance exercise performance in athletes. However, placebo and nocebo effects have not been sufficiently controlled, and the effect on aerobic metabolism parameters that determine endurance performance (e. g., oxygen cost of running, lactate threshold, and maximal oxygen uptake {[}(V)over dotO(2max)]) has been equivocal. Thus, we circumvented limitations from previous studies to test the effect of IPC on aerobic metabolism parameters and endurance performance in well-trained runners. Methods: Eighteen runners (14 men/4 women) were submitted to three interventions, in random order: IPC; sham intervention (SHAM); and resting control (CT). Subjects were told both IPC and SHAM would improve performance compared to CT (i. e., similar placebo induction), and IPC would be harmless despite circulatory occlusion sensations (i. e., nocebo avoidance). Next, pulmonary ventilation and gas exchange, blood lactate concentration, and perceived effort were measured during a discontinuous incremental test on a treadmill. Then, a supramaximal test was used to verify the (V)over dotO(2max) and assess endurance performance (i. e., time to exhaustion). Results: Ventilation, oxygen uptake, carbon dioxide output, lactate concentration, and perceived effort were similar among IPC, SHAM, and CT throughout the discontinuous incremental test (P > 0.05). Oxygen cost of running, lactate threshold, and (V)over dotO(2max) were also similar among interventions (P > 0.05). Time to exhaustion was longer after IPC (mean +/- SEM, 165.34 +/- 12.34 s) and SHAM (164.38 +/- 11.71 s) than CT (143.98 +/- 12.09 s; P = 0.02 and 0.03, respectively), but similar between IPC and SHAM (P = 1.00). Conclusions: IPC did not change aerobic metabolism parameters, whereas improved endurance performance. The IPC improvement, however, did not surpass the effect of a placebo intervention. (AU)

• Processo FAPESP: 14/15877-8 - Efeito de pré-condicionamento isquêmico sobre mecanismos determinantes do desempenho aeróbio em corredores de alto nível
• Beneficiário: Jeann Luccas de Castro Sabino de Carvalho
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 15/03572-0 - Efeito de pré-condicionamento isquêmico nos membros inferiores sobre a recuperação autonômica cardíaca após o exercício físico em corredores de média/longa distância
• Beneficiário: Tiago Obeid de Freitas
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 14/24294-6 - Contribuição tônica do quimiorreflexo periférico no controle vagal do coração em repouso e na recuperação do exercício em pacientes com insuficiência cardíaca crônica
• Beneficiário: Bruno Moreira Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular