Of those that were published, no scientific evidence existed to support the athletes’ claims of reduced delayed onset muscle soreness (DOMS), less fatigue, improved performance, improved venous return, less edema post-competition and faster recovery.
As a result, their use during competition was not endorsed by many clinicians, athletic trainers and physical therapists. However, due to their popularity and continued use by professional and recreational athletes, scientists have investigated the mechanisms behind the purported benefits of compression garments. As a result, several peer-reviewed papers have been published on the topic and it is certainly a topic worth revisiting.
What Does Compression Gear Do?
Clinically, compression gear is designed to deliver specific levels of pressure to the affected limb. Typical pressure ranges are from 20 to 40 millimeters of mercury, depending on the limb and the clinical indication.
Off the shelf stockings may deliver 30 to 40 millimeters of mercury of pressure whereas custom stockings deliver 40 millimeters of mercury pressure at the ankle, 36 millimeters of mercury at the lower calf, and 21 millimeters of mercury at the upper calf. These pressure levels are designed to enhance venous return and reduce edema in patients with various vein disorders.
They look cool, come in a variety of fashionable colors and patterns, keep you warm at that in-between temperature, are easily discarded should you get too warm (and are not half as expensive as a technical shirt), and are trademarks for athletes including Allen Iverson and Paula Radcliffe.
Compression garments are one of the latest trends to hit the performance gear shelves. As with most trends that come and go in sports, it takes a while for the science to catch up with the practice. About five years ago, when compression gear first became popular as a potential ergogenic aid, there were very few published reports regarding their efficacy.
Several other studies have been published to support that compression garments reduce post-exercise declines in jump height, minimize strength loss, decrease muscle edema (swelling), and ease muscle soreness (http://www.ncbi.nlm.nih.gov/pubmed/23007487, http://www.ncbi.nlm.nih.gov/pubmed/20195085, http://www.ncbi.nlm.nih.gov/pubmed/20376479).
In the instance of running, although anecdotal arguments exist to support that compression garments improve performance during an event, the literature proves otherwise. Compression calf sleeves did increase oxygen saturation of the blood in subjects at rest before the exercise and during the recovery process, but no improvements were observed in running performance or the time to fatigue in subjects wearing calf sleeves, according to Menetrier, A.Compression sleeves increase tissue oxygen saturation but not running performance.
One of the laboratories that reported a beneficial effect of compression garments on muscle recovery also evaluated well-trained endurance athletes during exercise. Results showed that subjects’ ratings of perceived exertion, muscle soreness and time to exhaustion were unaffected by compression garments (http://www.ncbi.nlm.nih.gov/pubmed/20391083). Even though one report demonstrated an effect of compression garments on endurance running performance in athletes, the experimental design involved a custom designed whole body compression garment (full-length bottoms and long-sleeved tops).
In the article,The effects of whole-body compression garments on prolonged high-intensity intermittent exercise, by J.A. Sear, the practicability of this garment is questionable, and the improvements in total distance covered (less than 1/4 mile) and tissue oxygenation were modest. Similarly, although results from another laboratory indicated that wearing lower-body compression garments improved venous flow, the performance improvements were deemed trivial to athletes, as they did not correspond to improvements in endurance running performance (http://www.ncbi.nlm.nih.gov/pubmed/21725102).
When Should I Wear Them?
A review of the literature does indicate that compression garments have a place in sport, particularly for athletes who train and compete on a regular basis. While there are relatively few scientific reports of performance gains while wearing compression gear during competition, there is certainly compelling evidence to support that compression gear helps the recovery process.
Whether following a hard race, a long training run or a hard workout, compression garments can facilitate recovery and reduce post-exercise muscle soreness. The critical point to remember is the importance in allowing the body to incorporate necessary recovery strategies so that proper adaptation may occur.
While one would caution against constant use of compression gear, it does hold a place in the athletes’ arsenal, similar to ice-baths, massage and nutritional supplements.
Also, keep in mind that these reports were conducted with newly purchased compression garments or custom made compression garments that delivered a specific level of pressure to the limb under investigation. Very few athletes who purchase compression gear for sport are aware of the pressure gradient or how well it is maintained during competition or over the life of the garment. Repeated washings and wear are sure to reduce the compression after just a few uses, subsequently altering their effect.
In the healthy athlete, compression gear serves a different role. Most who choose to wear compression garments anticipate that they will experience improved circulation and mechanics. It is thought that compression garments may reduce muscle oscillations which will theoretically optimize the contraction direction of muscle fibers, resulting in improved mechanical efficiency and running kinematics.
Use of compression gear may also reduce vibration in skeletal muscle during training and competition. It is hypothesized that the reduced vibration would contribute to less muscle trauma, and as a result, less fatigue and biomechanical alterations during the course of an endurance event. Following the event, the combined benefit of these outcomes would be reduced exercise-induced muscle damage.
As a result, athletes are expected to experience less soreness, edema and faster recovery in the days after exercise.
Based on these speculative mechanisms of effect, marketing terminology for compression gear includes words such as improved thermoregulation, reduced muscle oscillation, and increased circulation. As an informed consumer, it is always good to take a look at the most recent data which is summarized below. Please keep in mind that the literature is difficult to interpret with one main stance on compression gear due to the experimental design discrepancies among various studies.
For example, there is significant variability among studies to include the type and duration of exercise, the measures used as indicators of performance or recovery, the training and health status of the participants, the duration that the compression garments were worn, the total duration of wear, the pressure applied and the area of the body covered.
What Does the Research Show?
Individual assessment of compression gear research shows some benefit, although it’s mainly during the recovery process. For example, one report says no significant differences in sprint performance (time or distance covered), throwing performance (distance or accuracy), heart rate response or blood measures.
The one change observed during exercise was higher skin temperature. However, during the 24-hour period post-exercise, blood markers of muscle damage were lower and the athletes reported less soreness, according to the study by Duffield, R. and M. Portus, Comparison of three types of full-body compression garments on throwing and repeat-sprint performance in cricket players.
In another example, subjects performed 30-minute bouts of moderate and high-intensity running on a treadmill while wearing compression gear. According to the study by Lovell, D.I., Do compression garments enhance the active recovery process after high-intensity running? Decreased heart rate and lactic acid were documented during the recovery period post-exercise. The results of this study are encouraging as reducing lactic acid and recovery heart rate have important implications for athletes that perform repeated bouts of high-intensity exercise in a single competition.
By Maria Urso