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

INTERVENTION: 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 an eccentric cycling protocol (outlined below) followed by an assigned recovery intervention of either SCG tights, placebo (artificial sweetener) or control. Participants will remain in a supine lying down position and do nothing for the four hour recovery period. A number of performance, physiological and psychological measures will be taken to assess the effectiveness of SCG on recovery post‐exercise. These include whole and lower body performance, near‐infrared spectroscopy (NIRS), Doppler ultrasound, blood analysis, thigh girth and perceptual questionnaires (more details of these measures are explained in Step 4: Outcomes) Eccentric Cycling: This exercise intervention will consist of three 4‐min eccentric cycling efforts, with one min rest between each effort. During exercise, participants will be asked to maintain a pre‐determined level of force output, which will be visually displayed during the session. The first effort wi CONDITION: Muscle recovery; ; Muscle recovery Musculoskeletal ‐ Normal musculoskeletal and cartilage development and function Physical Medicine / Rehabilitation ‐ Other physical medicine / rehabilitation ; Post‐study ‐ immediately after the last testing session is complete (visit 4).] Blood Samples (Composite Primary Outcome): ; An indwelling cannulation will be inserted into an antecubital vein for the collection of 4‐mL blood samples. Blood samples will be analysed for pro and anti‐inflammatory markers (IL‐1ß, IL‐6, IL‐10, IL‐4) using commercially available kits (R&D Multiplex ELISA Kit). Samples will be collected, stored, and prepared as per manufacturer guidelines. Cannulations and blood collections will be undertaken by trained personnel under sterile conditions.[Pre Exercise ; Immediately post‐exercise and every 60 min for 4 hours ; 24 and 48 hours (primary timepoint) post‐exercise] Perceived muscle soreness (PMS) Questionnaire: ; This will be assessed via self‐palpation of the exercised muscle, where the participant will be asked to rate their level of soreness using a visual analogue scale (0 = nothing at all, 10 = extremely high). This questionnaire has been used in other research previously.[Pre Exercise ; Immediately post‐exercise and every 60 min for 4 hours ; 24 and 48 hours post‐exercise] Performance Tests ; To assess performance recovery following exercise countermovement jumps (CMJ) will be performed. ; ; ; [Pre Exercise ; Immediately post‐exercise ; 24 and 48 hours post‐exercise] To assess performance recovery following exercise, isometric mid‐thigh pulls (IMTP) will be performed. ; ; ; ; [Pre Exercise ; Immediately post‐exercise ; 24 and 48 hours post‐exercise] Total quality of recovery (TQR) Questionnaire: PRIMARY OUTCOME: Blood Samples (Composite Primary Outcome):; An indwelling cannulation will be inserted into an antecubital vein for the collection of 4‐mL blood samples. Blood samples will be analysed for markers of muscle damage (creatine kinase and C‐reactive protein) using commercially available kits (R&D Multiplex ELISA Kit). Samples will be collected, stored, and prepared as per manufacturer guidelines. Cannulations and blood collections will be undertaken by trained personnel under sterile conditions. [Pre Exercise; Immediately post‐exercise and every 60 min for 4 hours; 24 and 48 (primary time point) hours post‐exercise] Markers of Venous Return (Composite primary outcome):; Doppler ultrasound will be used to measure markers of venous return (venous cross‐sectional area, venous peak flow velocity and venous mean flow velocity) for the popliteal (behind the knee) and common femoral (upper‐thigh) veins. Each site will marked with a permanent marker to ensure consistency at each collection time point. Lubricating jelly will be applied to the skin at each site to help transmit the signal. Measures at the common femoral vein will be accessed with the garments folded down slightly. A small window will be cut in the garments, before participant is wearing SCG, to allow probe access to the popliteal vein. The angle of the transducer relative to the skin will be between 45 and 60 degrees, with the depth adjusted to insonate the total width of the veins. Ultrasound signal will be measured for approximately 60s at each site in order to obtain measures of venous return previously mentioned. Personnel trained in the use of ultrasound for venous measures will collect all measures. [Pre‐exercise; Immediately post‐exercise and every 30 minutes for 4 hours (4 hours post is primary timepoint); 24 and 48 hours post‐exercise] Muscle blood flow (Composite Primary Outcome):; Muscle blood flow and muscle oxygenation will be measured at the vastus lateralis and gastrocnemius medialis muscles using Near Infrared Spectroscopy (NIRS). An oximeter will be positioned on the lowest third of the vastus lateralis muscle, parallel to the long axis of the leg. A second oximeter will be positioned on the gastrocnemius medialis muscle belly, parallel to the major axis of the shin of the same leg. Each placement site will be shaved of excess hair to help ensure a good quality signal. The placement of each oximeter will be marked with a permanent marker to ensure consistency for each testing session (visit 2, 3 and 4). The NIRS device provides continuous, non‐invasive measurement of concentration changes in oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb) and total haemoglobin (tHb). Changes in muscle oxygenation will be monitored using an oximeter (Oxymon MKIII Near‐Infrared Spectrophotometer, Artinins Medical Systems, The Netherlands), with data transmitted simultaneously to a personal computer and acquired using (Oxysoft V3.0.53, Artinins Medical Systems, The Netherlands) software. To assess muscle blood flow, multiple venous occlusions (70 mmHg) will be performed. This technique requires the inflation of a pressure cuff, applied to the upper thigh, using an automated rapid cuff inflation system (Hokanson, Washington, USA). Blood flow into the muscle is then calculated by the rise in tHb (O2Hb + HHb). Three 20‐s venous occlusions, separated by 45 s of rest. The average of these three measurements will be used for data analysis. [Pre‐exercise; Immediately post‐exercise and every 30 minutes for 4 hours (4 hours post is primary timepoint); 24 and 48 hours post‐exercise] ; This will be assessed by participants rating their perceived recovery on a scale from 6 (no recovery) to 20 (maximal recovery). This questionnaire has previously been used and validated. ; [Pre Exercise ; Immediately post‐exercise and every 60 min for 4 hours SECONDARY OUTCOME: Belief Questionnaire ‐ Immediately following the familiarisation session, participants will be asked to complete a ‘belief questionnaire’. This questionnaire is designed to assess the participant’s anticipated belief in both recovery intervention’s effectiveness. Participants will be asked to rate anticipated effectiveness on a 0 to 5‐point Likert scale, with 0 representing ‘not effective at all’ and 5 representing ‘extremely effective’. Participants will be allocated their recovery intervention, matched and counterbalanced based on their anticipated effectiveness in both interventions. Participants will also be asked to complete a belief questionnaire immediately after the last testing session (visit 4), which is designed to assess the participant’s perceived effectiveness of the completed recovery intervention. This questionnaire has been designed specifically but has been used previously.[Pre study ; Prior to all performance tests, 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. ; The CMJ is a valid and reliable test for estimating explosive power of the lower limb. The CMJ test will be performed with subjects standing on a force place with feet in a hip wide position. Participants will be required to perform a quick downward movement to approx. 90° knee flexion, followed by a fast upward vertical jump as high as possible. Upon landing, both feet will be required to be within the frames of the force plate. When performing the CMJ, hands will be placed on hips to eliminate influence of arm swing on jump performance. A set of 5 CMJs will be completed, with 8 seconds rest between repetitions. Vertical ground reaction forces (N) and jump height (cm) will be used for analysis. ; Prior to all performance tests, 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. ; 24 and 48 hours post‐exercise] INCLUSION CRITERIA: There will be inclusion criteria by which participants must meet in order to be considered for the study. Participants will be required to have performed between 2 to 4 resistance training session a week, for a minimum of six months. Furthermore, participants usual resistance training sessions will include lower body exercises such as squats or deadlifts due to the eccentric component of the exercise protocol in the study. This will be assessed by potential participants completing a Physical Activity Questionnaire before being accepted to participate in the study. The justification for this inclusion criteria is that participants of similar training experience will be recruited, in an attempt to minimize large variations in response to the exercise protocol. ; The IMTP is a reliable assessment of whole‐body maximum force generating capacity, and is regularly used to monitors athletes’ training progression. The test will be performed on a Smith Machine while standing on a force platform. The mid‐thigh position will be determined by marking the midpoint between the top of the patella and the inguinal crease of the front thigh. This site will be marked with a permanent marker, along with feet position, to ensure retest reliability. Participants will self‐select their hip and knee angles for the test with the height of the barbell adjusted to be in contact with the marked mid‐thigh position. Participants will be instructed to pull upward on an immovable bar for 3 seconds while standing on the force platform. Two repetitions will be performed separated by 2 min rest, with a third repetition performed if a 250 N difference is seen between peak forces of the first two efforts. Peak force (N) and rate of force development (N/s) will be used for analysis.