The idea of the compression garments descended from medical leggings that have been used to treat blood clots and circulatory disorders. I would probably highlight Paula Radcliffe as the athlete that brought these into popular running culture, with them being used extensively by some athletes. From their humble beginnings as medical socks, you can now buy full body suits, leggings, tops and short length tights. You can probably cover your whole body in a compression garment!
The science behind them is simple:
• They reduce the muscle vibrations when on, so improve efficiency
• It promotes blood flow by constricting the area, so reducing fatigue
The big question is, do they work? From the following research I believe that they do work to promote recovery in the muscles but don't make you any more efficient in your running. However there may be physiological benefits, and if it is that extra 1% that takes you from 4:00 to 3:59:59 in your marathon then you can't complain about that!
I will first highlight a couple of studies carried out by Indiana University, where they examined the influence of compression garments on athletic performance; significantly they found that they had very little influence.
Abigal Lagman, a researcher from the Department of Kinesiology, carried a study entitled 'Lower leg compression sleeves: influence on running mechanics & economy in highly trainer distance runners'. So, a perfect study for us runners to digest.
The study found that there was no impact made on the oxygen consumption of the runners, so that means that there was no change in the economy or efficiency in the runner, and their running mechanic was not altered. The study was carried out on 16 male runners, with 2 x 12 minutes of running, one with and one without the compression sleeves. They would run at 3 speeds, 6:55 minute miles, 6 minute miles and 5:21 minute miles (each for 4 minute durations)
Efficiency was measured by the oxygen consumption levels, and these did not change. Running mechanic was measured by the contact time, stride length and frequency, again these figures were the same with and without the sleeves on. When you think about it, this seems very logical, a tiny bit of cloth is not going to change your mechanics.
There is an important side note. Four people (25%) had an average of greater than 1% increase in oxygen consumption, so they got worse. However four other people had an average of greater than 1% decrease in oxygen consumption, so they actually became more efficient. The subjects were questioned before the experiment, and those who had a favourable attitude to the compression garments were the ones who showed an improvement in oxygen consumption; their efficiency. It would appear that those who believe the technology works may well see an improvement in their running efficiency, however this hypothesis has not been fully tested to hold, but it is an interesting concept.
The second study done is not as significant for runners. It was done on upper garments and measured jump height for vertical jumps. Nathan Eckert, a student in the Department of Kinesiology undertook the research and they found no difference.
The third study I wish to look at and discuss was carried out by Rob Duffield and Marc Portus, from the British Journal of Sports Medicine 2007; 41:409 - 411.
They compared 3 types of full body compression garments on throwing and repeated sprint performance. The study used garments from Skins, adidas and Under Armour. I am going to ignore the discussion on throwing (as I don't know many runners who throw) but the sprint performance data should be of some relevance. In this area, they found no significant difference in heart rate levels, changes in body mass and blood measures. However there were significant differences in skin temperature, which were higher and creatine kinase levels, which were lower. An elevation of creatine kinase levels is an indication of damage to muscles. People experienced lower levels of post exercise soreness. There was no difference between brands.
What these results show is that as a recovery tool, when worn 24 - 48 hours after exercise it will promote physiological recovery from high intensity exercise, regardless of physiological changes.
In a 1996 paper 'Influence of Compression Garments on Vertical Jump Performance in NCAA Division I Volleyball Players' by Dr Kraemer he concluded that "The data indicates that compression shorts, while not improving single maximal jump power, have a significant effect on repetitive vertical jumps by helping to maintain higher mean jumping power", so in practical terms for people doing vertical jumps "compression shorts may have value for enhancing power output over a repeated number of jumps".
It is important to note that this test is done on vertical jumps so may not be wholly applicable to running but it is interesting that they provided some improvement.
Another study from the International Journal of Sports Physiology and Performance on 12 cyclists for a 1-hour time trial. They found that the physiological markers improved, including muscle oxygenation but performance was not affected at all.
On a practical level, I was asking a massage therapist about the compression socks and her opinion on them. What was interesting is that she notices a difference on the suppleness of people's calves after using them during a hard session compared to without. This leads on to my conclusion that I believe as a recovery tool these garments work. I have used a number of different products, including the skins recovery leggings and the Accapi action leggings -- both of which are very good products. My legs are not as sore in the morning if I sleep in them and I certainly feel the benefits after wearing them. My calfs and achilles are certainly not as tight.
So, wear the garments and see for yourself if they help. If they help you recover and so allow you to train more efficiently then for me, they are worth all the money in the world!