Ischemic Preconditioning and Repeated Sprint Swimming: A Placebo and Nocebo Study

Author(s)

Ferreira, Thiago N. ; Sabino-Carvalho, Jeann L. C. ; Lopes, Thiago R. ; Ribeiro, Indyanara C. ; Succi, Jose E. ; Da Silva, Antonio Carlos ; Silva, Bruno M.

• Document type: Journal article
• Source: MEDICINE AND SCIENCE IN SPORTS AND EXERCISE; v. 48, n. 10, p. 1967-1975, OCT 2016.
• Web of Science Citations: 23

Abstract

Purpose Ischemic preconditioning (IPC) has been shown to improve performance of exercises lasting 10-90 s (anaerobic) and more than 90 s (aerobic). However, its effect on repeated sprint performance has been controversial, placebo effect has not been adequately controlled, and nocebo effect has not been avoided. Thus, the IPC effect on repeated sprint performance was investigated using a swimming task and controlling placebo/nocebo effects. Methods Short-distance university swimmers were randomized to two groups. One group (n = 15, 24 1 yr {[}mean SEM]) was exposed to IPC (ischemia cycles lasted 5 min) and control (CT) (no ischemia); another (n = 15, 24 +/- 1 yr) to a placebo intervention (SHAM) (ischemia cycles lasted 1 min) and CT. Seven subjects crossed over groups. Subjects were informed IPC and SHAM would improve performance compared with CT and would be harmless despite circulatory occlusion sensations. The swimming task consisted of six 50-m all-out efforts repeated every 3 min. Results IPC, in contrast with SHAM, reduced worst sprint time (IPC, 35.21 +/- 0.73 vs CT, 36.53 +/- 0.72 s; P = 0.04) and total sprints time (IPC, 203.7 +/- 4.60 vs CT, 206.03 +/- 4.57 s; P = 0.02), moreover augmented swimming velocity (IPC, 1.45 +/- 0.03 vs CT, 1.44 +/- 0.03 ms(-1); P = 0.049). Six of seven subjects who crossed over groups reduced total sprints time with IPC versus SHAM (delta = -3.95 +/- 1.49 s, P = 0.09). Both IPC and SHAM did not change blood lactate concentration (P = 0.20) and perceived effort (P = 0.22). Conclusion IPC enhanced repeated sprint swimming performance in university swimmers, whereas a placebo intervention did not. (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: 15/03186-3 - 20th Annual Congress of the ECSS
• Grantee: Bruno Moreira Silva
• Support Opportunities: Research Grants - Meeting - Abroad