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James R. Broatch, David J. Bishop and Shona Halson

oxygenation 16 , 17 during continuous and intermittent high-intensity running, consistent with enhanced muscle pump and venous return demonstrated in clinical studies. 18 , 19 Compression clothing has also been reported to improve arterial perfusion to forearm muscles by more than 2-fold, 20 which was

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Dennis-Peter Born, Christoph Zinner, Britta Herlitz, Katharina Richter, Hans-Christer Holmberg and Billy Sperlich

Purpose:

The current investigation assessed tissue oxygenation and local blood volume in both vastus lateralis muscles during 3000-m race simulations in elite speed skaters on ice and the effects of leg compression on physiological, perceptual, and performance measures.

Methods:

Ten (6 female) elite ice speed skaters completed 2 on-ice trials with and without leg compression. Tissue oxygenation and local blood volume in both vastus lateralis muscles were assessed with near-infrared spectroscopy. Continuous measures of oxygen uptake, ventilation, heart rate, and velocity were conducted throughout the race simulations, as well as blood lactate concentration and ratings of perceived exertion before and after the trials. In addition, lap times were assessed.

Results:

The investigation of tissue oxygenation in both vastus lateralis muscles revealed an asymmetry (P < .00; effect size = 1.81) throughout the 3000-m race simulation. The application of leg compression did not affect oxygenation asymmetry (smallest P = .99; largest effect size = 0.31) or local blood volume (P = .33; 0.95). Lap times (P = .88; 0.43), velocity (P = .24; 0.84), oxygen uptake (P = .79; 0.10), ventilation (P = .11; 0.59), heart rate (P = .21; 0.89), blood lactate concentration (P = .82; 0.59), and ratings of perceived exertion (P = .19; 1.01) were also unaffected by the different types of clothing.

Conclusion:

Elite ice speed skaters show an asymmetry in tissue oxygenation of both vastus lateralis muscles during 3000-m events remaining during the long gliding phases along the straight sections of the track. Based on the data, the authors conclude that there are no performance-enhancing benefits from wearing leg compression under a normal racing suit.

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Roy J. Shephard

Attention is drawn to specific practical and ethical concerns that may arise when researchers study responses to vigorous exercise in populations with disabilities. It is argued that the study of such individuals can provide important information regarding responses to exercise by nondisabled people. This thesis is illustrated by selected examples relating to (a) central versus peripheral limitation of oxygen transport, (b) the contribution of muscle pumping to venous return during vigorous exercise, (c) the contribution of sympathetic innervation to aerobic training responses, (d) the ceiling of muscle fiber hypertrophy, (e) the functional demands of daily living, and (f) the responsiveness of young children to aerobic training. It is concluded that exercise physiologists have already learned much about normal reactions to exercise by studies involving those disabilities, but there remains scope for many further investigations exploiting the special characteristics of such populations.

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Llion A. Roberts, Johnpaul Caia, Lachlan P. James, Tannath J. Scott and Vincent G. Kelly

Purpose: External counterpulsation (ECP) has previously been used to treat cardiac patients via compression of the lower extremities during diastole to increase venous return and coronary perfusion. However, the effects of ECP on exercise performance and markers of recovery in elite athletes are largely unknown. Methods: On 2 separate occasions, 48 h apart, 7 elite National Rugby League players performed an identical 60-min field-based conditioning session followed by a 30-min period of either regular ECP treatment or placebo. Power measures during repeated cycle bouts and countermovement jump height and contraction time derivatives were measured at rest and 5 h postexercise. Saliva samples and venous blood samples were taken at rest, postexercise, and 5 h postexercise to assess stress, inflammation, and muscle damage. Results: After ECP treatment, cycling peak power output (P = .028; 11%) and accumulated peak power (P = .027; 14%) increased compared with the placebo condition. Postexercise plasma interleukin 1 receptor antagonist only increased after ECP (P = .024; 84%), and concentrations of plasma interleukin 1 receptor antagonist tended to be higher (P = .093; 76%) 5 h postexercise. Furthermore, testosterone-to-cortisol ratio was increased above baseline and placebo 5 h postexercise (P = .017–.029; 24–77%). The ratio of postexercise salivary α-amylase to immunoglobulin A decreased after treatment (P = .013; 50%) compared with the placebo control. Conclusions: Exercise performance and hormonal indicators of stress were improved and inflammation markers were reduced following acute ECP.

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Justin M. Stanek

Clinical Scenario:

The popularity of compression socks has increased substantially among athletes, particularly those participating in endurance events such as running and triathlon. Companies are increasingly marketing compression stockings to runners, triathletes, and other endurance athletes for the benefits of improved performance and/or decreased recovery time. Originally developed for the treatment of deep-vein thrombosis, compression socks are now marketed as a tool to improve venous return, thus believed to improve both performance and recovery in athletes. The use of compression socks during training aims to help the skeletal-muscle pump, increase deep venous velocity, and/or decrease blood pooling in the calf veins and alleviate delayed-onset muscle soreness. The scenario is a 28-y-old recreational triathlete seeking your advice while training for her first half-Ironman. She occasionally complains of tightness in the calves both during and after running. She wants your opinion on the effectiveness of using compression socks to help her performance and recovery.

Focused Clinical Question:

What is the effectiveness of using graduated compression socks for improving athletic performance and decreasing recovery time in healthy endurance athletes?

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Fernando S. Lobo, Andreia C.C. Queiroz, Natan D. Silva Junior, Fabio L. Medina, Luiz A.R. Costa, Tais Tinucci and Claudia L.M. Forjaz

during sustained seated position. 26 After the exercise sessions with intentional or ad libitum hydration, SV decreased as previously reported. 10 , 11 , 22 , 25 , 27 This reduction has been attributed to a decrease in venous return 11 explained by a decrease in plasma volume and/or an increase in

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Amanda L. Zaleski, Linda S. Pescatello, Kevin D. Ballard, Gregory A. Panza, William Adams, Yuri Hosokawa, Paul D. Thompson and Beth A. Taylor

/or after marathons due to an athlete’s perceived enhancement of performance and/or recovery. Such purported improvements are largely fueled by a manufacturer’s claims that compression socks reduce microtrauma, enhance venous return, reduce swelling space, and/or accelerate clearance of exercise metabolites

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Kayla E. Boehm, Blaine C. Long, Mitchell T. Millar and Kevin C. Miller

, Lindsey AW , Abernathy B , Richardson T . Venous return at various right atrial pressures and the normal venous return curve . Am J Physiol . 1957 ; 189 : 609 – 615 . PubMed ID: 13458395 doi:10.1152/ajplegacy.1957.189.3.609 10.1152/ajplegacy.1957.189.3.609 13458395 28. Kase K , Wallis J

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Ewan R. Williams, James McKendry, Paul T. Morgan and Leigh Breen

presented by de Glanville et al, 20 who reported a decrease in blood pressure following the removal of CGs. The authors speculated that, upon removal, any elevation in pressure dropped immediately, resulting in a relative decrease in venous return and peripheral resistance. 20 Interestingly, others have

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Bethany Forseth and Stacy D. Hunter

also be due to the activity of the baroreceptor reflex. Aerobic activities are more rhythmic in nature facilitating venous return via the action of the muscle pump. 24 While the isometric contraction sequences in yoga may be sufficient to elicit a reactive hyperemic response temporarily, the