Muscle Ischemic Preconditioning does not Improve Performance during Self-Paced Exercise.

Muscle ischemic preconditioning (IP) has been found to improve exercise performance in laboratory tests. This investigation aims at verifying whether performance is improved by IP during self-paced exercise (SPE) in the field. 11 well-trained male runners performed 3 randomly assigned 5 000 m self-paced running tests on an outdoor track. One was the reference (RT) test, while the others were performed following muscle IP (IPT) and a control sham test (ST). Average speeds were measured during each test. Mean values in oxygen uptake VO₂, aerobic energy cost (AEC) during race and post-race blood lactate (BLa) were gathered. Data showed that none of the studied variables were affected by IPT or ST with respect to the RT test. Average speeds were 4.63±0.31, 4.62±0.31 and 4.60±0.25 m•s^-1 for the RT, the ST and the IPT tests, respectively. Moreover, there was no difference among tests in speed reached during each lap. VO₂ was 3.5±0.69, 3.74±0.85 and 3.62±1.19 l•min^-1. AEC was 1.04±0.15, 1.08±0.1 and 1.09±0.15 kcal•kg^-1•km^-1. Finally, post-race BLa levels reached 12.85±3.54, 11.88±4.74 and 12.82±3.6 mmol•l^-1. These findings indicate that performance during SPE is not ameliorated by ischemic preconditioning, thereby indicating that IP is not suitable as an ergogenic aid. [ABSTRACT FROM AUTHOR]