Many a patient has passed through our practice raving about the benefits of graduated compression gear (tights, shorts, sleeves, socks etc.). There is no denying the perceived benefit of compression gear, particularly in aiding muscle recovery.
Athletes love their compression socks.
The popularity of compression gear has skyrocketed amongst athletes, particularly those participating in endurance events such as running and triathlon. Originally developed for the treatment of deep-vein thrombosis, compression gear is now marketed as a tool to improve both performance and recovery in athletes.
Thus far, much of the evidence appears to be anecdotal…happy athletes with encouraging stories.
But what do the experts say?
Theoretically, compression gear is designed to improve running performance and recovery by exerting a pressure gradient. Hypothetically, this pressure gradient:
- Reduces the available space for swelling.
- Provides mechanical support to the working muscles.
- Improves blood and lymph circulation.
While this sounds really impressive to runners looking for an edge, the clinical research does not consistently support these claims. In terms of the perks of compression gear on muscle performance and recovery in a laboratory setting, the evidence is inconclusive at best.
Clinical laboratory versus real life.
Although objective outcomes, such as oxygen uptake, blood lactate levels, performance and output remain lacking in a day-to-day clinical setting, subjective outcomes such as pain/perceived muscle soreness continue to show benefits when compared to placebo interventions (garments with no pressure gradient).
The trouble with the majority of the research is that it has been performed in a laboratory setting, rather than the blood, sweat and tears associated with a real-life endurance event.
Until recently… when a group of researchers at our very own Stellenbosch University in the Western Cape decided to test the benefit of knee-high compression socks on performance and recovery in runners competing in the Two Oceans ultra-marathon in Cape Town.
Two Oceans as the testing field.
The consecutive stretching and shortening of muscles over 56 km of undulating hard tarmac (particularly the large downhill component in the Two Oceans), along with prolonged exposure to the elements of outdoor running create a mechanical stress in a runner’s muscles that is difficult to match in a simulated lab environment, making this study more ‘ecologically valid’ than the myriad of studies preceding it.
The study looked at the following parameters:
- The performance of the runners – running time, minutes per km, heart rate and oxygen consumption.
- The amount of exercise-induced muscle damage. This is an assessment of muscle damage, including disruption of muscle structure, muscle enzyme increases in the blood (an indicator of muscle injury), extended impairment of muscle function (i.e. muscular strength), delayed onset of muscle soreness (DOMS), perceived fatigue and pain, reduced flexibility, muscle stiffness and swelling.
- The recovery time of exercise-induced muscle damage back to normal.
The following groups were measured:
- Runners wearing knee-high graduated compression socks (GCS) during the race and for a 48 hour recovery time after the race (Group 1 – GCS RUN+REC).
- Runners wearing GCS during the race ONLY (Group 2 – GCS RUN).
- Runners wearing normal non-compression knee-high socks (Group 3 – NON GCS control group).
Helps Performance – FICTION. Helps recovery – FACT.
There were no significant differences between the groups in terms of performance. Sorry guys, there is no substitute for the hard graft of endurance training!
However… there were very significant differences in terms of muscle recovery.
- GCS RUN+REC and RUN showed less swelling in the ankles and calves post run, contributing to less stiffness and better circulation to injured muscle tissue. This was markedly better at 24 and 48 hours post event in the GCS RUN+REC group.
- Significantly reduced perceived muscle soreness in the calves, quads and hamstrings of the same 2 groups compared to the NON GCS runners, with a further improvement in the GCS RUN+REC group at 24/48 hours.
- Higher oxygen and lower lactate levels blood circulating through the compressed areas in both GCS groups, more pronounced at 24/48 hours in the RUN+REC group.
- Reduced exercise-induced muscle damage in the calves of both GCS groups, more pronounced in the RUN+REC group at 24/48 hours post event. This was tested through inflammatory indicators of muscle damage in the blood, as well as performance in functional tests such as vertical jumps at 0/24/48 hours post event.
The underlying reasoning for the above results was attributed to:
- External pressure over the lower leg veins and muscles improves the ‘muscle pump’ action of the calves, aiding blood and lymph flow. This increases the amount of oxygen and nutrients being fed to the muscle, but also helps to clear waste products like lactate away from the injured tissue more quickly.
- The GCS acts like a ‘dynamic cast’ to stabilise the injured muscle, assisting alignment and regeneration of damaged muscle tissue. It also plays a supportive role during the run, by limiting vertical ‘bounce’ or oscillation of the muscle tissue, thereby limiting mechanical stress on the working muscle.
- The compression limits ‘available space’ for swelling to collect and accumulate, thereby reducing ankle/calf swelling and stiffness.
Takeaway message
The evidence suggests that wearing of GCS during and 48 hours post endurance events significantly minimises the effects of exercise-induced muscle damage to the muscles underlying the compression. There is also the benefit of less perceived muscle soreness in the other leg muscles.
Wearing GCS for multiple-day events, helps to limit the accumulative effect of exercise-induced muscle damage.
So there we have it…. The proof is in the pudding! We can present you with the facts, but at the end of the day it comes down to individual preference and experience. You get to write your own story, fact or fiction.
References:
Fletcher, L. et al. (2014) ‘Efficacy of Compression Socks to Enhance Recovery in Distance Athletes’, Sport and Art, 2(2), pp. 15–18.
Stanek, J. M. (2017) ‘The Effectiveness of Compression Socks for Athletic Performance and Recovery’, Journal of Sport Rehabilitation, 26, pp. 109–114.
Welman, E. et al. (2011) ‘The value of graduated compression socks as a post- exercise recovery modality in long distance runners’. PhD Thesis, Department of Sport Science, University of Stellenbosch.