A Literature Review done for my Masters in Sports Medicine (MsSpMed), University of Queensland, Australia 2017

• Introduction
• Results
• Discussion
• Indicators of Recovery
• Muscle Swelling
• Muscle Soreness
• Serum Muscle Enzyme Levels
• C-Reactive Protein
• Voluntary Muscle Contraction and Physical Tests
• Event-specific Tests
• Limitations of Current Research
• Challenges in Quantifying Recovery
• Placebo Effect
• Recommendations
• Future Studies
• Patient Advice
• Conclusion
• References

Introduction

Compression stockings have traditionally been used as a form of mechanical prophylaxis against deep vein thrombosis in patients who require prolonged bed rest. They increase mean deep venous velocity, reduce venous pooling and improve venous return2.

In the last 2 decades, wearing compression stockings during and after exercise to improve venous return has been applied to athletes looking to improve performance. It is postulated that when worn during exercise, Compression Garments (CG) may confer support to the muscles and reduce muscular oscillations, thus reducing muscular trauma. When worn after exercise, the external pressure of CG may reduce inflammatory response by reducing intercellular space available for swelling, hemorrhage and hematoma formation12,17. The use of CG following exercise is also thought to be an effective method in removing metabolic waste products, such as lactate, that accumulate during exercise, and therefore, enhance recovery4. These mechanisms are thought to improve recovery after training bouts. It is argued that with an improvement in recovery, CG will enable athletes to tolerate a higher training volume, frequency and intensity24,30 and therefore achieve better sporting performance.

As such, in a bid to improve athletic performance, researchers are looking at ways to improve recovery, such as through the use of CG.

This literature review aims to discuss the effect of CG on recovery in athletes and to make recommendations for future research.

Results

A literature search was done on Pub Med. There is a high heterogeneity of test protocols, across different sports and activities to induce muscle damage, from which recovery is measured from. 14 recent studies were found with  5 studies investigating on the use of CG on the recovery from running, 5 from plyometrics, 1 from cycling, 2 from rugby and 1 from whole body resistance exercise.

The results are summarised in Table 1.

Discussion

Review of the current literature shows that the use of CG can reduce perceived muscle soreness after a strenuous bout of exercise. Its effects on other markers of recovery such as serum muscle enzyme levels, are inconclusive. In addition, there are several weaknesses to these studies that limit our interpretation of the results.

Indicators of Recovery

There are several indicators of recovery, which have been used in various studies to measure recovery among athletes.

Muscle Swelling

Swelling is derived from inflammation secondary to muscle damage. Thigh or calf girths and ultrasound imaging of vastus lateralis swelling13 are used as surrogate measurements of muscle swelling. It is suggested that external pressure created by CG may reduce intramuscular space available for swelling and promote stable alignment of muscle fibres like a splint, attenuating the inflammatory process. Only one study13 out of 4 in this review found a positive effect of CG on muscle swelling. But whether the resolution of muscle swelling indicates complete muscle recovery is still unknown, thus more studies need to be done to ascertain this relationship before results can be interpreted.

Muscle Soreness

The presence of muscle soreness suggests that recovery has not fully taken place. It is also thought to be the body’s natural protective mechanism following damaging exercise to prevent full muscle activation exacerbating damage21. However, its relationship with athletic recovery is not fully understood, i.e. the absence of muscle soreness may not indicate full recovery for the athlete. The extent of muscle soreness is also affected by the “repeated bout” effect, where subsequent bouts of similar exercise will produce lesser and lesser muscle soreness20. This means that even though an athlete may go through the same exercise routine over numerous sessions while experiencing a shorter duration of muscle soreness after each session, it does not mean that he is recovering faster after each session.

In addition, the measurement of muscle soreness is subjective, with all studies utilising the Visual Analogue Scale (VAS) to quantify the extent of soreness. Webb et al.7 used a blood pressure cuff wrapped around a golf ball to exert pressure over the quadricep muscles. A standard 100mmHg pressure was applied and subjects rated the pain using the VAS. Jakeman et al.8,9 and Hill et al.3 had participants assume an unweighted squat of 90 degrees and mark their pain on the VAS. Others10,11 utilised the VAS without any interventions to elicit muscle soreness.

There is a clear benefit of CG2,3,6,7,8,9,11,12,13,15 either worn during exercise or after exercise for an extended duration, towards reducing muscle soreness. However, more studies need to be done to understand the relationship between muscle soreness and athletic recovery.

Serum Muscle Enzyme Levels

Creatine kinase (CK) and Lactate Dehydrogenase (LDH) are enzymes found in muscles. When muscle tissues are damaged, these enzymes leak into the blood. Elevated blood concentration of CK or LDH is frequently used as a marker of muscle damage. However, it has been shown that CK values vary greatly among individuals, with some athletes having chronically low CK serum levels and some having higher levels, depending on the level of training, absolute muscle mass and muscle fibre types18. With such a high level of variability among individuals, it is not a reliable marker of recovery. Compared to CK, LDH is not as commonly used as CK as a marker of muscle damage4. Furthermore, studies25 have found no change in pre and post exercise LDH levels in subjects following downhill running, suggesting its poor reliability.

Therefore, variability among subjects may explain why only 213,14 out of the 11 studies measuring CK as a marker of recovery found positive impact with the use of CG while the rest did not find any significant difference.

As such, serum levels of CK and LDH are currently not reliable in the monitoring of recovery among athletes.

C-Reactive Protein

C-reactive protein (CRP) is an inflammatory marker that measures inflammatory load in the body. However in a study by Wiewelhove et al.19, no changes in CRP were observed between baseline and post High Intensity Interval Training (HIIT), suggesting that it is an unreliable marker for recovery.

Voluntary Muscle Contraction and Physical Tests

Several studies7,9,11 had subjects perform a single leg vertical jump and measured jump height to compare between groups. While other studies4,6,8,13 measured maximal voluntary isometric force to measure muscle strength as a form of comparison.

48,9,11,13 out of 9 studies found a positive impact of CG on such physical tests. However, there are limitations to the interpretation of this results as these tests are not specific in nature and thus may not correlate well to specific sports performance – i.e. recovery in the ability to jump high does not necessary mean a recovery in the ability to run fast for a runner1.

Event-specific Tests

Instead of analysing an alteration in biochemical markers or muscle power to measure recovery, event-specific tests determines recovery by having the athlete complete an exercise specific to his sport. For example, Armstrong et al.1 had subjects performing a treadmill run test 2 weeks after a marathon to measure recovery.

31,5,12 out of 4 studies found a positive impact of CG on event-specific recovery. However, these tests do come with its limitations, such as being more difficult logistically to set in a controlled environment. One may also debate if running on a treadmill is truly specific when running competitions are carried out on the road or the track; and if cycling on a stationary bike can truly replicate outdoor race cycling.

Limitations of Current Research

Challenges in Quantifying Recovery

As discussed above, it is a challenge to accurately quantify recovery in athletes. It is  important to understand that there are several aspects of recovery. These include the normalisation of physiological functions such as blood pressure, return of the body’s cells to homeostasis, restoration of energy stores and replenishment of cellular energy enzymes, all of which may take different amount of time to return to baseline after a strenuous bout of exercise26. In addition, another aspect of recovery is the athlete’s perception of fatigue. Peripheral fatigue is often defined as a local impairment within the muscle, commonly attributed to a depletion of muscle glycogen28. Central fatigue is less understood but is well accepted to be due to the brain reducing neural activity down the motor pathways from the brain to the spinal cord26 in an attempt to protect the body from further damage.

In view of this multi-dimensional nature of recovery, isolated markers such as perceived muscle soreness or serum CK levels, may not produce a complete assessment of recovery. Perhaps then, the best way to measure recovery is through event-specific testing – to have the athlete do the same activity again to see if he can perform at the same or higher level after the use of CG. Only with this method can both central and peripheral fatigue be taken into account for.

Placebo Effect

Blinding of the participant in these studies is challenging as compression garments are not new in the market and athletes have been exposed to marketing materials by CG companies, informing them of the benefits of CG.

Armstrong et al.1 attempted to get around this by informing both control and compression groups that the recovery effect is due to the physical wearing of the socks and not the extent of compression. A diabetic sock was also used as a placebo as it looked similar to a compression sock. However, the researchers did not comment on the rates of assignment diagnosis by participants of both groups to determine if blinding was successful.

Hill et al.25 utilised a sham ultrasound treatment for the control group to let participants believe that they were provided with an alternative form of treatment or modality that could improve their performance.

Recommendations

Future Studies

As discussed, current studies in the literature have several limitations and with the challenges in determining true athletic recovery, it is difficult to interpret if CG provide a positive effect on athletic recovery. Future studies should adopt event-specific testing to determine recovery until a more objective marker of recovery is developed as well as ensuring adequate blinding of participants.

Patient Advice

Current literature supports the use of compression garments in the attenuation of perceived muscle soreness. As such, athletes who experience muscle soreness frequently from strenuous exercise, may benefit from wearing CG over the affected muscle groups.

Conclusion

Based on current literature, CG appears to be effective in attenuating the level of perceived muscle soreness after exercise. But whether this truly reflects the recovery status of the athlete is still debatable. More studies need to be done to investigate the effects of CG on other aspects of athletic recovery.

References

1. Armstrong SA, Till ES, Maloney SR, Harris GA. Compression socks and functional recovery following marathon running. Journal of Strength and Conditioning Research. 2015;29(2):528–533.
2. Ali A, Caine MP, Snow BG. Graduated compression stockings: Physiological and perceptual responses during and after exercise. Journal of Sports Sciences. 2007;25(4):413–419.
3. Hill JA, Howatson G, van Someren KA, Walshe I, Pedlar CR. Influence of compression garments on recovery after marathon running. Journal of Strength and Conditioning Research. 2014;28(8):2228–2235.
4. Davies V, Thompson KG, Cooper S-M. The effects of compression garments on recovery. Journal of Strength and Conditioning Research. 2009;23(6):1786–1794.
5. Hamlin MJ, Mitchell CJ, Ward FD, Draper N, Shearman JP, Kimber NE. Effect of compression garments on short-term recovery of repeated sprint and 3-Km running performance in Rugby union players. Journal of Strength and Conditioning Research. 2012;26(11):2975–2982.
6. Duffield R, Cannon J, King M. The effects of compression garments on recovery of muscle performance following high-intensity sprint and plyometric exercise. Journal of Science and Medicine in Sport. 2010;13(1):136–140.
7. Webb EC, Willems ME. Effects of wearing graduated compression garment during eccentric exercise. Medicina Sportiva. 2010;14(4):193–198.
8. Jakeman JR, Byrne C, Eston RG. Lower limb compression garment improves recovery from exercise-induced muscle damage in young, active females. European Journal of Applied Physiology. 2010;109(6):1137–1144.
9. Jakeman JR, Byrne C, Eston RG. Efficacy of lower limb compression and combined treatment of manual massage and lower limb compression on symptoms of exercise-induced muscle damage in women. Journal of Strength and Conditioning Research. 2010;24(11):3157–3165.
10. FRENCH DN, THOMPSON KG, GARLAND SW, et al. The effects of contrast bathing and compression therapy on muscular performance. Medicine & Science in Sports & Exercise. 2008;40(7):1297–1306.
11. Bieuzen F, Brisswalter J, Easthope C, Vercruyssen F, Bernard T, Hausswirth C. Effect of wearing compression stockings on recovery after mild exercise-induced muscle damage. International Journal of Sports Physiology and Performance. 2014;9(2):256–264.
12. DRILLER, M., HALSON, S.. The effects of lower-body compression garments on recovery between exercise bouts in highly-trained cyclists. Journal of Science and Cycling, North America, 2, jun. 2013.
13. Kraemer WJ, Flanagan SD, Comstock BA, et al. Effects of a whole body compression garment on markers of recovery after a heavy resistance workout in men and women. Journal of Strength and Conditioning Research. 2010;24(3):804–814.
14. Gill ND. Effectiveness of post-match recovery strategies in rugby players. British Journal of Sports Medicine. 2006;40(3):260–263.
15. Pruscino CL, Halson S, Hargreaves M. Effects of compression garments on recovery following intermittent exercise. European Journal of Applied Physiology. 2013;113(6):1585–1596.
16. ARMSTRONG RB. Mechanisms of exercise-induced delayed onset muscular soreness. Medicine & Science in Sports & Exercise. 1984;16(6):529???538.
17. Kraemer, William J.; French, Duncan N.; Spiering, Barry A. Compression in the treatment of acute muscle injuries in sport. International SportMed Journal . 2004, Vol. 5 Issue 3, p200-208. 9p.
18. Brancaccio P1, Maffulli N, Limongelli FM. Creatine kinase monitoring in sport medicine. Br Med Bull. 2007;81-82:209-30. Epub 2007 Jun 14.
19. Wiewelhove T, Raeder C, Meyer T, Kellmann M, Pfeiffer M, Ferrauti A. Markers for Routine Assessment of Fatigue and Recovery in Male and Female Team Sport Athletes during High-Intensity Interval Training. Tauler P, ed. PLoS ONE. 2015;10(10):e0139801.
20. Paddon-Jones D, Muthalib M, Jenkins D. The effects of a repeated bout of eccentric exercise on indices of muscle damage and delayed onset muscle soreness. Journal of Science and Medicine in Sport. 2000;3(1):35–43.
21. Westing SH, Cresswell AG, Thorstensson A. Muscle activation during maximal voluntary eccentric and concentric knee extension. European Journal of Applied Physiology and Occupational Physiology. 1991;62(2):104–108.
22. Lawrence D, Kakkar VV. Graduated, static, external compression of the lower limb: A physiological assessment. British Journal of Surgery. 1980;67(2):119–121.
23. Born DP1, Sperlich B, Holmberg HC. Bringing light into the dark: effects of compression clothing on performance and recovery. Int J Sports Physiol Perform. 2013 Jan;8(1):4-18.
24. Barnett A. Using recovery Modalities between training sessions in elite athletes. Sports Medicine. 2006;36(9):781–796.
25. SCHWANE JA, JOHNSON SR, VANDENAKKER CB, ARMSTRONG RB. Delayed-onset muscular soreness and plasma CPK and LDH activities after downhill running. Medicine & Science in Sports & Exercise. 1983;15(1):51-56.
26. Bishop PA, Jones E, Woods AK. Recovery from training: A brief review. Journal of Strength and Conditioning Research. 2008;22(3):1015–1024.
27. Jeffreys I. A multidimensional approach to enhancing recovery. Strength and Conditioning Journal. 2005;27(5):78–85.
28. Jentjens R, Jeukendrup AE. Determinants of post-exercise Glycogen synthesis during short-term recovery. Sports Medicine. 2003;33(2):117–144.
29. 10. Wahl P, Mathes S, Achtzehn S, Bloch W, Mester J. Active vs. Passive recovery during high-intensity training influences hormonal response. International Journal of Sports Medicine. 2013;35(07):583–589.
30. 1. 2XU compression. http://www.2xu.com/us/compression.html. Accessed January 28, 2016.