A study by the University of Essex Human Performance Unit concluded that compression leggings improve "energy expenditure while exercising, hasten recovery and improve proprioception.” The researchers took eleven recreational runners and over four sessions, used analysis software, took blood tests and measured oxygen levels as they ran and jumped in fitted or oversized compression tights. ”The runners demonstrated that they used less energy when running at a sub maximal speed.“

Hill, J., Howatson, G., van Someren, K., Leeder, J., and Pedlar, C. (2013). Compression garments and recovery from exercise-induced muscle damage: a meta-analysis. British Journal of Sports Medicine, 0, pp.1-7.

Connolly DAJ, Sayers SP, McHugh MP. Treatment and prevention of delayed onset muscle soreness. J Strength Cond Res 2003;17:197–208.

Kraemer WJ, Bush JA, Wickham RB, Denegar CR, Gómez AL, Gotshalk LA, Duncan ND, Volek JS, Putukian M, Sebastianelli WJ., “Influence of compression therapy on symptoms following soft tissue injury from maximal eccentric exercise”, 2001. Results from this study underline the importance of compression in soft tissue injury management.

Kraemer WJ, French DN, Spiering BA. Compression in the treatment of acute muscle injuries in sport. Int Sport Med J 2004; 5:200–8 ABSTRACT: “Strenuous physical exercise can induce damage and injury to muscle tissue that is manifested as soreness, a decreased range of motion, swelling, pain, and impaired functional capacity. Compression is a therapeutic technique widely used in the treatment of muscle and other soft tissue injuries, though evidence in support of this remedial therapy has until recently being largely anecdotal. Recent scientific research has indicated that external compression can be an effective treatment that minimises swelling, improves the alignment and mobility of scar tissue, and improves proprioception in an injured joint consequent to eccentric damage models and DOMS. The principles behind compressive treatment methods are based on known principles affecting the lymphatic system, reducing oedema, skeletal muscle contractions, local pressure gradients, and the influence of gravity. The rationale for applying compression to injured tissue are, (i) its theoretical ability to reduce oedema via the creation of an external pressure gradient, (ii) by reducing the space available for swelling to accumulate, haemorrhage and haematoma formation can be decreased, and (iii) providing mechanical support that can facilitate the capacity to produce force which is critical for rehabilitation. Compression involves a “dynamic immobilisation” strategy that allows for greater neural input and the capacity for limited movement during the recovery process. This treatment protocol represents an easily administered therapy that can be used effectively without great financial cost.”

Doan BK, Kwon Y, Newton RU, et al. Evaluation of a lower-body compression garment. J Sport Sci 2003; 21 (8): 601-10. ABSTRACT: The aims of this study were to determine how custom-fit compression shorts affect athletic performance and to examine the mechanical properties of the shorts. Ten male and 10 female track athletes on a university’s nationally competitive track team, specializing in sprint or jump events, participated in the study. Testing utilized the compression shorts with loose-fitting gym shorts as the control garment. Several significant effects were revealed for the custom-fit compressive garment. Although 60 m sprint time was not affected, hip flexion angle was reduced. Skin temperature increased more and at a faster rate during a warm-up protocol. Muscle oscillation was decreased during vertical jump landing. Countermovement vertical jump height increased when the participants were wearing the custom-fit compression garment. In materials testing, the elasticity of the compressive garment provides increased flexion and extension torque at the end range of extension and flexion, respectively, and may assist the hamstrings in controlling the leg at the end of the swing phase in sprinting. The compressive garment significantly reduced impact force by 27% compared with American football pants alone. Through various mechanisms, these findings may translate into an effect on athletic performance and a reduction in injuries.

Hamlin MJ1, 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”, 2012 Nov; 26. ABSTRACT: “The aim of this study was to investigate whether wearing compression garments during recovery improved subsequent repeated sprint and 3-km run performance. In a randomized single-blind crossover study, 22 well-trained male rugby union players (mean ± SD: age 20.1 ± 2.1 years, body mass 88.4 ± 8.8 kg) were given a full-leg length compressive garment (76% Meryl Elastane, 24% Lycra) or a similar-looking non-compressive placebo garment (92% Polyamide, 8% Lycra) to wear continuously for 24 hours after performing a series of circuits developed to simulate a rugby game. After the 24-hour recovery, garments were removed and a 40-m repeated sprint test (10 sprints at 30-second intervals), followed 10 minutes later by a 3-km run, was completed. One week later, the groups were reversed and testing repeated. Relative to the placebo, wearing the compressive garment decreased time to complete the 3 km by 2.0% ± 1.9% (mean ± 90% confidence interval). Additionally, average sprint times improved (1.2% ± 1.5%) and fatigue was diminished (-15.8% ± 26.1%) during the repeated sprint test in the compression group compared with the placebo group. Delayed onset muscle soreness was substantially lower in the compression group compared with the placebo group, 48 hours after testing. Wearing compressive garments during recovery is likely to be worthwhile, and very unlikely to be harmful for well-trained rugby union players.”