BRINGING SCIENCE TO TREATMENT

Giving recovery the squeeze

Some time ago, editor Alicia Filley explored the effectiveness of graded compression garments (GCGs) on athletic performance and recovery for our sister publication Peak Performance. As she explained, the theory behind the use of GCGs by athletes stems from the regular application of their usage in the medical field. In hospitals, GCGs are worn by patients who spend a significant amount of time in bed. The GCGs improve their circulation and decrease the edema that forms from pathology or inactivity (see figure 1).

Figure 1: Mode of action of GCGs


The review of the literature at that time (2016) revealed that GCGs, worn during activity or after, didn’t improve running performance. Some of the data showed that wearing compression leggings between cycling time trails had an 80% likely chance of boosting trial times(1). Concerning recovery, GCGs did decrease swelling and help eliminate metabolites; however, the effect on the subjective measures of delayed onset muscle soreness (DOMS) was questionable. Lacking clarity on the physiological parameters impacted by GCGs, sports medicine doctors in Germany decided to use recently developed technological measures to quantify the recovery effects of GCGs in an attempt to decrease the performance diminishing effects of DOMS(2).

The study enrolled 14 healthy 20 to 30-year-olds to perform eccentric calf exercises while wearing a vest weighted to about 25% of their body weight. Before the exercise, the scientists collected measurements of calf muscle perfusion, stiffness, circumference, soreness, passive ankle dorsiflexion, and creatine kinase. They executed five sets of 30 repetitions, continuing until fatigue during the last set. Right after the exercise, the subjects donned a GCG (of less than 20mmHg compression force) on one calf and wore the sock continuously for the next 60 hours.

After the allotted period, the subjects rated their DOMS using a visual analog scale (VAS) for pain both at rest and when going downstairs. Using acoustic radiation force impulse (ARFI) elastography, researchers measured the muscle stiffness of both calf muscles. This new technology gives information about the characteristics of tissues without the need for an invasive biopsy. Changes in muscle stiffness often indicate functional impairment(2). The study also measured dynamic perfusion using contrast-enhanced ultrasound (CEU). In previous studies, increased perfusion corresponded with healing and tissue regeneration, while decreases in blood flow usually indicated impairment(2). In addition to the other clinical measurements, all participants underwent a post-intervention MRI.

Does compression decrease DOMS and improve recovery?

The measures of soreness, perfusion, circumference and passive ankle range of motion between the leg with the GCG and the control leg did not differ 60 hours after exercising. However, stiffness of the gastrocnemius muscle (GM) did decrease in the control leg while it remained the same in the GCG leg. Interestingly, the stiffness values for the soleus muscle were the same between both legs after wearing the GCG.

The post-intervention MRI found edema in both calves, suggesting that perhaps GCGs don’t decrease swelling as effectively as thought, or that GCGs of higher compression values are needed to influence this factor. The similarity in the other clinical measures between legs is likely because the edema didn’t differ between legs.

Despite the noted effect of wearing the GCG on the stiffness of the GM, researchers are still questioning the physiology of this response. While scientists can guess as to the mechanism of this effect, the question is, “Does it matter?” If the post-exercise edema still exists and the athlete’s perception of DOMS stays the same, why bother suggesting they wear the GCGs? Increased muscle stiffness indeed improves performance, but an athlete that ‘feels’ sore likely won’t take advantage of the unchanged level of muscle stiffness to give it their all in the next event. Therefore, unless there is a medical reason to wear them, such as an athlete who is post-surgical, has a long travel time to an away game, or has known vascular issues, take GCGs off the post-workout recovery menu.

References

1. De Glanville, K. Teacher Fellowship Poster. 2008 http://royalsociety.org.nz/media/programmes-funds-teacher-fellowships-profiles-2008-kieran-de-glanville.pdf
2. JOSPT. 2018 Nov;48(11):887

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