Comparison of two different recovery strategies on post-exercise blood flow and recovery.

1 BRIEF NAME Sports Compression Garments (SCG) 2 WHY Sports compression garments (SCG) are commonly used in athletes to improve recovery from exercise. The mechanisms by which SCG improve recovery are largely unknown, but may be closely associated with alterations in blood flow. As such, SCG have been implicated in increasing venous return, thereby assisting the removal of muscle metabolites post-exercise and preventing secondary muscle damage. However, research investigating the effects of SCG on blood flow, particularly during the post-exercise period, is limited. This research aims to investigate the effects of SCG on markers of venous return and muscle blood flow post-exercise, and the influence this has on aspects of muscle recovery. 3 MATERIALS Materials: SCG tights (https://www.2xu.com/au/p/refresh--recovery-tights/MA4419b.html?dwvar_MA4419b_color=BLACK_NERO&lang=en_AU#prefn1=restrictedProduct&prefv1=no&lang=en_AU&start=1) will be provided by sports apparel company, 2XU. 4. PROCEDURES Participants will complete a lower-body resistance training session (outlined below) followed by an assigned recovery intervention of either SCG tights, placebo (artificial sweetener) or control. One Rep Max Testing: Participants will be testing to determine their 1RM for leg press. This 1RM data will be used to set an individual workload for the lower-body resistance training session during visit 2. Prior to testing of 1RM, subjects will perform a standardized warm-up consisting of 5 min cycling at 1 W per kg body mass, 10 repetitions of body weight squats, 10 repetitions on each leg of bodyweight walking lunges, high knee run over 20 m, heel kick run over 20 m, 3 submaximal CMJs and 1 maximal CMJ. Following the warm-up, participants will perform a total of two warm-up sets, 10 reps with no weight on the leg press machine followed by 5 reps at 50% of estimated 1RM. Participants will then perform a repetition at an estimated 90% of 1RM. If repetition is completed successfully, and with correct technique, participants will perform another one repetition effort with gradually increasing resistance until failure or loss of technique. A 3 min rest period will be allowed between max effort attempts. A successful 1RM will be the greatest mass lifted with the correct form through a complete range of motion. Due to maximal testing for determination of 1RM, a 7-day period will be required between visits 1 and 2. Lower-Body Resistance Training Session: After the completion of performance tests, subjects will perform a lower-body resistance training session. Subjects will perform leg presses that emphasise the eccentric movement, for 8 sets of 6 reps. Weight lifted for 6 reps will be approximately 85% of previously tested 1RM (1). Subjects will assume a seated position on the leg press machine, and place feet shoulder-width apart and flat on the platform. Subjects will be required to lower the resistance platform slowly for a duration of 4 s (time recorded by investigator) and then push the platform back to starting position by extending the legs until knees are only slightly bent. This will be considered one rep. A 3 min rest period will be taken between each set. Prior to the beginning of 8 sets, participants will perform a total of two warm-up sets, 10 reps with no weight on the leg press machine and 8 reps at 50% of 1RM. A spotter will be positioned on each side of the machine to assist in the concentric (pushing) phase in the event participants experience local fatigue. A similar protocol has been shown to result in increased creatine kinase levels and ratings of perceived muscle soreness at 24 and 48 h post-exercise. 5 WHO PROVIDED SCG tights will be provided to participants by Mr Shane O’Riordan. Mr O’Riordan is a PhD student at Victoria University in Exercise Physiology. Mr O’Riordan has conducted previous research using SCG as part of his PhD research with Victoria University in Sport Physiology. In addition, Mr O’Riordan works at the Australian Institute of Sport as a recovery physiologist, where he regularly prescribes the use of SCG as a recovery modality for athletes. 6 HOW SCG tights will be provided to the participants individually post-exercise face to face. 7 WHERE The intervention of SCG tights will occur at the Exercise Physiology Laboratory, Building P, Room PB151, Victoria University, Ballarat Rd, Footscray, VIC, 3011. 8 WHEN and HOW MUCH The intervention of SCG tights will be provided post-exercise for a duration of four hours. After the four hour recovery period, participants will remove SCG tights. 9 TAILORING The degree of pressure applied and gradient distribution are critical for the effectiveness of SCG. Manufacturer fitting guidelines are typically acquired from an individual’s height and weight, meaning anthropometric variations in limb size and structure are likely to affect the pressure exerted by SCG. Therefore, the level of pressure exerted by SCG will be measured using the kikuhime device. This device contains a small air-filled piece of plastic that is placed between the garment and the skin. The pressure applied by the garment is then displayed on a monitor in real time, and to the nearest mmHg. Pressure will be measured at six sights on the right lower-limb. SCG will have a desired target pressure (23-32 mmHg at the calf and 12-17 mmHg at the thigh). In the event target pressure is not achieved, another SCG will be tested until the desired pressure is achieved and appropriate sizes noted for each participant. Assignment of SCG will be determined during the first visit for the SCG group.