Haemodynamic responses of wearing low-pressure sports compression tights during an orthostatic challenge in healthy individuals

Objectives: While previous studies have demonstrated an ergogenic effect of sport compression garments in exercise performance and recovery, the possible underlying mechanisms remain unclear. Claims for improved venous return from wearing sport compression garments with a low compression pressure remain unproven. The aim of this study was to determine the pressure profile exerted by low-pressure sports compression tights, and to investigate using a non-invasive Doppler ultrasound cardiac output monitor (USCOM), whether the compression applied will influence haemodynamic responses during an orthostatic challenge. Design: A randomized-crossover design. Methods: Thirty-three healthy participants (18 male and 15 female) underwent two trials, each consisting of lying supine and 70° head-up tilt wearing either a low-pressure sports compression tights (CT) or track pants (CON). Stroke volume (SV) and cardiac output (CO) were measured non-invasively using USCOM; heart rate (HR) and non-invasive blood pressure were measured, and systemic vascular resistance (SVR) was derived. Results: The SV and CO was lower at 70° head-up tilt than in supine but wearing CT attenuated the decline in SV (25.9 ± 11.6 cm³ CT vs. 35.9 ± 11.4 cm³ CON, p < 0.001), CO (1.1 ± 0.7 L min⁻¹ CT vs. 1.4 ± 0.6 L min⁻¹ CON, p < 0.05), HR (8.8 ± 8.4 beat min⁻¹ CT vs. 15.9 ± 9.7 beat min⁻¹ CON, p < 0.001) and SVR (740 ± 504 d s cm⁻⁵ CT vs. 961 ± 560 d s cm⁻⁵ CON, p < 0.005). The mean arterial pressure (3.3 ± 4.1 mmHg CT vs. 3.6 ± 4.5 mm Hg CON, p > 0.05) was similar in both trials. Conclusions: Healthy individuals wearing low-pressure sports compression tights experienced less severe haemodynamic disturbance such as decreases in CO, SV, HR and SVR during an orthostatic challenge.