>It seems that we’ve all been bitten by the compression bug. You can’t go to a running race longer than a 10k without seeing tons of pairs of brightly colored compression socks and calf sleeves. Companies such as TYR and 2XU have been marketing compression clothing (tights, shorts, etc) over the past year or so. Compression has become all the rage.
The question has always been, though, to what extent does compression actually help an endurance athlete? Are there physiological gains? Does compression merely offer a placebo affect?
The topic of compression and its effectiveness for endurance athletes has been debated for years. Just Google it, and you’ll find tons and tons of articles, posts and websites touting both the benefits and the lack thereof. It’s been well established, though, through scientific studies that compression (both passive compression via socks/sleeves and mechanical compression via intermittent pneumatic compression devices) provide benefits to sedentary, injured, or recovering patients. Furthermore, research shows that there appears to be specific recovery benefits for athletes.
As part of my research in advance of publishing reviews of CEP Compression Calf Sleeves and the Recovery Pump System (both forthcoming), I dug in and read countless scientific articles relating to compression in general. Trust me; there have been a plethora of studies done relating to compression and the athlete.
Many studies attempted to explain why compression was good and how compression worked. There were several studies in the late 1900’s that suggested that compression augments the normal pumping mechanism that muscles exert on the venous system, thus creating greater blood flow back to the heart (Siegel et al, 1974; O’Donnell et al, 1979; Choucair & Phillips, 1998; Bergan & Sparks, 2000; Morris & Woodcoco, 2004).
Other studies focused on the structural muscle support that compression garments offer. The studies found that in general, compression garments forcibly restricted the space available inside muscles for fluid accumulation, thereby reducing swelling and aiding in recovery (Friden et al, 1986; Jakeman et al, 2010). Additionally, compression garments were found to reduce muscle oscillations (Kraemer et al, 1998) and enhanced muscle regeneration (Kraemer et al, 2001).
Numerous studies have investigated compression garments’ ability to impact performance in athletes. This is where the research gets a little cloudy as to the value of compression. Very few of these studies have actually focused on endurance athletes. In fact, most studies relating to the impact of compression upon performance have focused on sprinting, jumping and cycling. The goal of many of these studies was to determine if compression helped one improve athletic skills. Like, for example, the height of jumps. When we hear of disparate findings as they relate to compression, it’s in this arena that we typically find the variances. The bottom line is that the research that has been completed thus far is relatively inconclusive as to the performance enhancement opportunities provided by compression.
One study that did focus on endurance athletes’ performance was a noteworthy study completed by Kemmler and colleagues (2009).
The Kemmler study is perhaps the most well-known study relating to the performance improving characteristics of recovery garments; it’s a study published by CEP on their website, and was cited in many of the studies I reviewed as part of my research. The Kemmler study examined twenty-one experienced distance runners for improvements in time under work, aerobic and anaerobic capacity, total work, and peak treadmill velocity. In this study, the runners showed improvement in duration of time under work (meaning at peak intensity), peak treadmill velocity, and total work (in watts). The study did not show any increase in aerobic or anaerobic capacity.
Most of us don’t wear compression socks or sleeves thinking that they will turn us into Kenyans. We wear them because we’ve heard that they aid in recovery.
There have been many studies investigating the recovery aspects associated with compression. In general, the data seem to indicate that compression aids recovery. There are a number of reasons why – and I’ll go into them, but in another article. Additionally, though, this aspect is where the concept of placebo impact is introduced. There are studies where data indicate that some of the positive effects may have been placebo. Two studies compared the effects of compression garments with a placebo garment. Ali et al (2010) and Duffield et al (2008 and 2010) both found that their subjects perceived no differences between the compression garments and the placebo.
I’ll go into much more detail in a future article, but there is new research that appears to indicate that compression garments are a valuable tool in post-exercise recovery for long-distance runners.
Dr. Karen Welman, of the University of Stellenbosch, in South Africa, recently published her dissertation, “The value of graduated compression socks as a post-exercise recovery modality in long distance runners” (March 2011). Her study was focused on ultramarathoners in an actual race setting (versus a clinical setting) and sought to determine if compression socks aid in recovery during strenuous exercise. Moreover, Dr. Welman’s study sought to identify the optimal time post exercise in which an athlete should wear compression socks.
A portion of Dr. Welman’s work was published in Medicine & Science in Sports & Exercise (May 2010, Vol 42, Issue 5, page 55).
Dr. Welman’s studies generated several principal findings: (a) That the use of knee-high compression socks as a recovery aid and as a preventative method, (b) that wearing compression socks during a recovery period contributes to less swelling and possibly reduced additional muscle disruption during recovery, and (c) that compression socks limit the structural damage in the calf muscle while contracting and during impact in the run. There were additional findings relative to the amount of pressure that is most applicable in compression garments.
When most of us think about compression items, we usually think about sock and calf sleeves. These types of compression garments fall into a category that the medical industry calls “passive compression”. As I’ve indicated above, there appears to be scientific evidence that supports the use of compression as a recovery tool for endurance athletes.
Passive compression is not the only game in town.
There is another type of compression – mechanical compression – that offers at least the same benefits as passive compression, if not more. Folks in the medical business will tell you that Intermittent Sequential Pneumatic (ISP) devices offer excellent results in combating deep vein thromboses. ISP is essentially like inserting your leg into a full leg-length blood pressure cuff. The cuff inflates progressively (moving up your leg) – meaning you don’t get an entire leg squeeze at once.
There have been at least half a dozen studies on the performance and recovery effects of ISP on athletes. Each of these has indicated that ISP provides for reduced pain, faster removal of lactic acid and other metabolic wastes, and reduction of swelling. Additionally, two studies – one by Wiener, et al (2001) and one by Waller, et al (2006) indicated that ISP provides a “significant enhancement of performance”, provides benefits in terms of abating performance reduction following repeated exercise, and reduces soreness both shortly following exercise and for a period up to 48 hours post exercise.
Based upon the research that I’ve done, and on my own highly un-scientific observations, I’d have to agree that compression is a good recovery tool. I’ve used compression sleeves for a couple of years now, and had positive results. This year I’ve supplemented passive compression with ISP through a device supplied to me by one of my sponsors, Recovery Pump. I’ve had very positive results, which I’ll share in a couple of reviews next week – one on CEP’s compression sleeves, the other on the Recovery Pump system.