Improve Running Speed by Cutting Off Circulation to Your Legs
Funny title, but is there any truth to it? A new study, published today looks at that question. Entitled "Effect of Ischemic Preconditioning on Lactate Accumulation and Running Performance", the study looked at the use of ischemic preconditioning on running performance in 5k time trials. Ischemic preconditioning (IPC) is an experimental technique for producing resistance to the loss of blood supply, and thus oxygen, to tissues of many types. If the blood supply to an organ or a tissue is impaired for a short time (usually less than five minutes) and then restored two or more times so that blood flow is resumed, the downstream cells (those below the cut-off point) of the tissue or the organ are robustly protected from a final ischemic (loss of blood) insult. In the case of this study, the researchers performed bilateral leg occlusion (they blocked the blood to the legs) and then had the runners perform some running intervals followed by a 5k.
According to previous studies, the protective effect of ischemic preconditioning has two windows of protection. The first lasts between 4–6 hours and has been named classical or early preconditioning. The second window begins at 24 hours lasting up to 72 hours post the ischaemia and reperfusion stimulus. The study published today looked at the effects of classical or early preconditioning, and what effects they found. The control group did not show any running performance (of course), but the runners receiving the IPC improved their 5k times by 34 seconds! Yes, 34 seconds. That is an incredible time improvement for a 5k. By repeatedly cutting off the blood to the legs, and then allowing them to recover, the leg muscles were better able to deal with the final lactate accumulation that took place during the 5k. In essence, the leg muscles became temporarily more efficient at processing oxygen and in putting off lactate accumulation, something every runner can benefit from.
The study is preliminary, and I am sure there will be more concerning IPC and running, but the preliminary results seem promising, if not interesting. How one would go about performing this technique either pre-race or simply as part of their training is up in the air. However, I think it is remarkable that one can potentially drop 30+ seconds off their time over the course of a 5k using this technique. Furthermore, what does this mean for longer distances? The "second window" of protection in using ICP lasts between 24 and 72 hours. Is it possible to somehow use ICP a day before a race and speed up your time? It might be. The science is still out, but it sure is interesting.