Effect of Ischemic Preconditioning on Endurance Performance Does Not Surpass Placebo

Author(s)

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

• Document type: Journal article
• Source: MEDICINE AND SCIENCE IN SPORTS AND EXERCISE; v. 49, n. 1, p. 124-132, JAN 2017.
• Web of Science Citations: 25

Abstract

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)

• FAPESP's process: 14/15877-8 - Effect of ischemic preconditioning on mechanisms that determine the aerobic performance in high level runners
• Grantee: Jeann Luccas de Castro Sabino de Carvalho
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 15/03572-0 - Effect of ischemic preconditioning of the lower limbs on cardiac autonomic recovery after exercise in middle/long distance runners
• Grantee: Tiago Obeid de Freitas
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 14/24294-6 - Tonic contribution of the peripheral chemoreflex to the vagal control of the heart at rest and recovery from exercise in patients with chronic heart failure
• Grantee: Bruno Moreira Silva
• Support Opportunities: Regular Research Grants