Title

Reliability of laser Doppler, near-infrared spectroscopy and Doppler ultrasound for peripheral blood flow measurements during and after exercise in the heat

Document Type

Journal Article

Publisher

Taylor and Francis

School

School of Medical and Health Sciences

Comments

Originally published as: Choo, H. C., Nosaka, K., Peiffer, J. J., Ihsan, M., Yeo, C. C., & Abbiss, C. R. (2017). Reliability of laser Doppler, near-infrared spectroscopy and Doppler ultrasound for peripheral blood flow measurements during and after exercise in the heat. Journal of Sports Sciences, 35(17), 1715-1723. Original article available here

Abstract

This study examined the test-retest reliability of near-infrared spectroscopy (NIRS), laser Doppler flowmetry (LDF) and Doppler ultrasound to assess exercise-induced haemodynamics. Nine men completed two identical trials consisting of 25-min submaximal cycling at first ventilatory threshold followed by repeated 30-s bouts of high-intensity (90% of peak power) cycling in 32.8 ± 0.4°C and 32 ± 5% relative humidity (RH). NIRS (tissue oxygenation index [TOI] and total haemoglobin [tHb]) and LDF (perfusion units [PU]) signals were monitored continuously during exercise, and leg blood flow was assessed by Doppler ultrasound at baseline and after exercise. Cutaneous vascular conductance (CVC; PU/mean arterial pressure (MAP)) was expressed as the percentage change from baseline (%CVCBL). Coefficients of variation (CVs) as indicators of absolute reliability were 18.7–28.4%, 20.2–33.1%, 42.5–59.8%, 7.8–12.4% and 22.2–30.3% for PU, CVC, %CVCBL, TOI and tHb, respectively. CVs for these variables improved as exercise continued beyond 10 min. CVs for baseline and post-exercise leg blood flow were 17.8% and 10.5%, respectively. CVs for PU, tHb (r2 = 0.062) and TOI (r2 = 0.002) were not correlated (P > 0.05). Most variables demonstrated CVs lower than the expected changes (35%) induced by training or heat stress; however, minimum of 10 min exercise is recommended for more reliable measurements.

DOI

10.1080/02640414.2016.1235790

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