I hope you have enjoyed the last 2 blog posts on simple performance enhancing concepts. Again I feel blessed that I could get Craig Pickering (@craig100m) to join me on the last blog around the benefits of caffeine. The third concept I want to introduce to you is called Ischemic Preconditioning. This involves the use of blood flow restriction cuffs and hence is something that sits well within my own passion of BFR training. If this article truly resonates with you please share it as I truly think there is something with this concept.
What is Ischemic Preconditioning (IPC)?
Ischemic preconditioning is a procedure that exposes a tissue to brief periods of ischemia and leads to resistance against cell injury that may be caused by subsequent prolonged ischemia and stress (Murray 1986). Ischemic preconditioning (IPC) is induced by cycles of inflation and deflation of a standard blood pressure cuff on a limb and releases a circulating protective factor into the bloodstream (22). Traditionally a concept used within the medial fraternity, IPC has been shown to protect the heart and lungs against ischemia–reperfusion injury in children undergoing cardiac surgery using cardiopulmonary bypass (4) and has also been shown to reduce evidence of cardiac damage in adults undergoing cardiac (10) and vascular surgery (1).
Mechanisms behind IPC
Although the mechanisms behind these actions are not clear, IPC may improve skeletal muscle blood flow by inducing conduit artery vasodilation, enhancing functional sympatholysis (18), and preserving endothelial and micro-vascular function during stress (6,14). In addition, IPC has demonstrated an ability to improve metabolic efficiency by attenuations ATP depletion (11,13) glycogen depletion (3), and lactate production (11,13). Consequently, there is a hypothesis that IPC may have a positive effect on skeletal-muscle function to enhance exercise capacity and athletic performance (8). The preconditioning response is divided into two phases. The early immediate phase persists for several hours and a delayed phase, with a later onset but longer duration, lasting 2 to 3 days (Figure 1) (22).
Sporting studies on IPC and performance
In a meta-analysis of the effects of IPC on human exercise performance, 21 studies were reviewed (12). The primary study outcomes related to exercise capacity or performance included measures of
- time-trial performance,
- power output,
- VO2 [maximal (VO2max) or peak (VO2peak),
- rating of perceived exertion (RPE), and
- blood lactate accumulation.
Secondary study outcomes included relevant cardiorespiratory variables (e.g., heart rate, blood pressure, and ventilation). Individual participant responses were obtained from 13 of the 21 studies (through the article and/or authors) and used to calculate the proportion of IPC responders and non-responders (Table 1).
Studies have reported that when IPC was applied to the lower limbs there was an increase in maximal workload during an incremental cycling test (5,9) and a decrease (-2.5%) in the time to complete a 5-km running trial (2). When applied to the upper limbs, IPC reduced (-1.1%) the time in 100 and 200m swimming trials (13), increased (+8.2%) underwater swimming distance (16), and decreased (-0.4%) the time to complete a 1000m rowing trial (16). IPC attenuated blood lactate accumulation during sub- maximal treadmill running (-1.07 mmol-1 or -25.4 %) (2), but had no effect during submaximal cycling (15). In tests of predominantly alactic anaerobic capacity, IPC increased (+2.3%) (21) and had no effect (8,19) on peak power output during repeated 6s cycling sprints.
The optimal method for implementing IPC is not conclusive, with variability in the size (muscle mass) of the occluded limb, the number of ischemic-reperfusion cycles, cycle length and the time lag between IPC and the start of exercise being factors that could influence outcome. However, most studies complete either 3 or 4 cycles of 5 min occlusion and reperfusion at pressures ranging between 200-220mmHg or 15-50 mmHg above resting systolic blood pressure (SBP). The optimal time lag between IPC and the start of exercise has not been investigated however current studies ranged from 5–105 min, with no clear relationships with exercise performance.
Current evidence suggests that IPC may be efficacious as an ergogenic aid to improve exercise performance and to gain a competitive advantage. Populations of IPC responders and non-responders may impact the large between-subject variability of results, and therefore caution should be used in the interpretation of mean group changes in exercise performance.
My own experiences using IPC with elite athletes
Despite the equivocal nature of IPC peer-review articles towards improving athletic performance I have been using this as a passive potentiator prior to warm-up and competition for a few years now. I predominately work within the sport of track and field (100-400m, Decathlete, Pole Vault, Discus and 3km Steeplechase) and use a modified methodology of 3 cycles of 3 minutes occlusion and reperfusion at a pressure of 50% arterial occlusion (Figure 2). After the athlete has completed the IPC, they remove the cuffs and proceed to perform their warm-up as they normally would. Real-world constraints to training and competition mean that this is perhaps the most pragmatic methodology available to these athletes. The deviation in methodology from literature is due to the following reasons:
- 3 cycles of 3 minutes: this was from a practical standpoint of time as these are athletes who need to then complete their own active warm-up prior to training or competition. Being able to decrease the total protocol time stated in literature (18min vs 40min) I felt was important also to ensure that I had buy-in from the athletes.
- Pressure set at 50% AO: This calculation (20) is based upon the pressures I set athletes for blood flow restriction training. I have had success at this pressure from a training standpoint and feel that the being able to individualize their pressures provides a safer and more accurate methodology to this practice. (I have created an excel spreadsheet to assist you with calculating this pressure.)
An additional IPC stimulus the day before or the morning of competition may also provide an additional benefit in the “delayed phase”. Despite this not being proven, my own post-graduate work has highlighted the role of mid-week hormonal responses to a stressor and it relationship to positive competition outcome 3-4days later (7). Therefore some of the biomarker responses in the delayed phase may provide a method to improve the hormonal status of an athlete. Irrespective this information provides a consideration to how we can approach our processes a few days leading into a competition.
Figure 2. Protocols for IPC prior to warm-up and competition
Although I do not have data that would stand up to a peer-review process I have a growing collection of subjective responses and objective data from elite athletes that I work with which leads me to believe that there is something of value. A typical response from the athletes is that they “get into” the warm-up a lot easier and generally feel more “active” through their musculature and hence feel better.
- 400m Paralympic sprinter:
- Method: IPC (passive) vs sled sprints (active) potentiation prior to flying 30m sprints:
- Result: no difference in flying 30m sprint times between active and passive potentiation. Perception that athlete can warm-up “quicker” and feel just as “active” with less energy consumption using IPC compared to the sled sprints.
- 100m Elite Junior (U20) male sprinter:
- Method: 2x5min prior to competition warm-up
- Result: subjective reporting of feeling of increased muscle freshness and power. “The muscles in the legs feel activated and ready to perform explosive activities before we actually start doing what is regarded as a ‘normal’ dynamic warm-up” – Paul DiBella OLY (@Paul_DiBella) 100m Olympic sprinter and coach.
- 400m Elite Junior (U20) female sprinter:
- Method: 3x3min prior to training – short speed session
- Result: able to “get into” warm-up a lot quicker than usual and consequently actually performs a shorter warm-up. Training speed times just as quick as typically longer warm-up.
Other observations and conclusions
I have also had conversations with numerous other coaches who report on improvement in sprint and repeat sprint ability from short (30m) to longer distances (150m). Working with elite athletes for almost 20 years, they tend to respond to things that they feel work well for them and consequently don’t need the peer review scrutiny to adopt new interventions. In conclusion I see IPC as a valuable tool to assist the warm-up process leading into important training sessions or competitions. At worst I have never had a negative response from an athlete using this. My question however from this body of information, is that why isn’t it adopted more widely amongst the sporting community?
Please remember to share this blog article with your colleagues and if you are using IPC please share with us all in the comments.
This article will also be available for download in the resources section of the website.
See you all soon.
- Ali, Z.A., Callaghan, C.J., Lim, E., Ali, A.A., Nouraei, S.A.R., Akthar, A.M., et al. Remote ischemic preconditioning reduces myocardial and renal injury after elective abdominal aortic aneurysm repair: A randomized controlled trial. Circulation. 116, 2007.
- Bailey, T.G., Jones, H., Gregson, W., Atkinson, G., Cable, N.T., and Thijssen, D.H.J. Effect of ischemic preconditioning on lactate accumulation and running performance. Medicine And Science In Sports And Exercise. 44: 2084–9, 2012.
- Beaven, C.M., Cook, C.J., Kilduff, L., Drawer, S., and Gill, N. Intermittent lower-limb occlusion enhances recovery after strenuous exercise. Applied Physiology, Nutrition, And Metabolism. 37: 1132–1139, 2012.
- Cheung, M.M.H., Kharbanda, R.K., Konstantinov, I.E., Shimizu, M., Frndova, H., Li, J., et al. Randomized Controlled Trial of the Effects of Remote Ischemic Preconditioning on Children Undergoing Cardiac Surgery. First Clinical Application in Humans. Journal Of The American College Of Cardiology. 47: 2277–2282, 2006.
- Crisafulli, A., Tangianu, F., Tocco, F., Concu, A., Mameli, O., Mulliri, G., et al. Ischemic preconditioning of the muscle improves maximal exercise performance but not maximal oxygen uptake in humans. Journal Of Applied Physiology (Bethesda, Md : 1985). 111: 530–6, 2011.
- Downey, J.M., Davis, A.M., and Cohen, M. V. Signaling pathways in ischemic preconditioning. Heart Failure Reviews. 12: 181–188, 2007.
- Gaviglio, C.M. and Cook, C.J. Relationship between Midweek Training Measures of Testosterone and Cortisol Concentrations and Game Outcome in Professional Rugby Union Matches. Journal Of Strength And Conditioning Research. 28: 3447–3452, 2014.
- Gibson, N., White, J., Neish, M., and Murray, A. Effect of ischemic preconditioning on land-based sprinting in team-sport athletes. International Journal Of Sports Physiology And Performance. 8: 671–676, 2013.
- De Groot, P.C.E., Thijssen, D.H.J., Sanchez, M., Ellenkamp, R., and Hopman, M.T.E. Ischemic preconditioning improves maximal performance in humans. European Journal Of Applied Physiology. 108: 141–146, 2010.
- Hausenloy, D.J., Mwamure, P.K., Venugopal, V., Harris, J., Barnard, M., Grundy, E., et al. Effect of remote ischaemic preconditioning on myocardial injury in patients undergoing coronary artery bypass graft surgery: a randomised controlled trial. Lancet. 370: 575–579, 2007.
- Hausenloy, D.J. Ischemic preconditioning protects by activating prosurvival kinases at reperfusion. AJP: Heart And Circulatory Physiology. 288: H971–H976, 2004.
- Incognito, A. V., Burr, J.F., and Millar, P.J. Sports Medicine. 46: 531–544, 2016.
- Jean-St-Michel, E., Manlhiot, C., Li, J., Tropak, M., Michelsen, M.M., Schmidt, M.R., et al. Remote preconditioning improves maximal performance in highly trained athletes. Medicine And Science In Sports And Exercise. 43: 1280–1286, 2011.
- Jennings, R.B., Sebbag, L., Schwartz, L.M., Crago, M.S., and Reimer, K.A. Metabolism of preconditioned myocardium: Effect of loss and reinstatement of cardioprotection. Journal Of Molecular And Cellular Cardiology. 33: 1571–1588, 2001.
- Kido, K., Suga, T., Tanaka, D., Honjo, T., Homma, T., Fujita, S., et al. Ischemic preconditioning accelerates muscle deoxygenation dynamics and enhances exercise endurance during the work-to-work test. Physiological Reports. 3, 2015.
- Kjeld, T., Rasmussen, M.R., Jattu, T., Nielsen, H.B., and Secher, N.H. Ischemic preconditioning of one forearm enhances static and dynamic apnea. Medicine And Science In Sports And Exercise. 46: 151–155, 2014.
- Koch, S., Della-Morte, D., Dave, K.R., Sacco, R.L., and Perez-Pinzon, M.A. Journal of Cerebral Blood Flow and Metabolism. 34: 933–941, 2014.
- Kooijman, M., Thijssen, D.H.J., de Groot, P.C.E., Bleeker, M.W.P., van Kuppevelt, H.J.M., Green, D.J., et al. Flow-mediated dilatation in the superficial femoral artery is nitric oxide mediated in humans. Journal Of Physiology. 586: 1137–1145, 2008.
- Lalonde, F. and Curnier, D. Can Anaerobic Performance Be Improved By Remote Ischemic Preconditioning? Journal Of Strength And Conditioning Research / National Strength & Conditioning Association. 80–85, 2014.
- Loenneke, J.P., Allen, K.M., Mouser, J.G., Thiebaud, R.S., Kim, D., Abe, T., et al. Blood flow restriction in the upper and lower limbs is predicted by limb circumference and systolic blood pressure. European Journal Of Applied Physiology. 115: 397–405, 2014.
- Patterson, S.D., Bezodis, N.E., Glaister, M., and Pattison, J.R. The effect of ischemic preconditioning on repeated sprint cycling performance. Medicine And Science In Sports And Exercise. 47: 1652–1658, 2015.
- Pérez-Pinzón, M.A. and Perez-Pinzon, M. a. Neuroprotective effects of ischemic preconditioning in brain mitochondria following cerebral ischemia. J Bioenerg Biomembr. 36: 323–327, 2004.