Acute Changes in Arterial Function Post High-Intensity Lower Extremity Cycling.

The purpose of this study was to assess the acute arterial blood flow velocity of the lower extremity (LE) immediately after a bout of high-intensity LE cycling exercise. Twenty-eight healthy males (n = 14) and females (n = 14) aged 20.9 ± 1.7 years participated in this study. All subjects performed a single bout of high-intensity cycling (70% of HRR) for 45 min. The subjects' LE blood flow velocity, heart rate (HR), systolic blood pressure (SBP), and oxygen saturation (SpO2) were measured at rest, immediately post-, post-15 min., and post- 30 min. intervention. A repeated-measures ANOVA with a Bonferroni adjustment was used for each measure to compare the responses at each time point. Resting blood flow velocity (37.5 ± 11.3 cm/s) and HR (64.9 ± 11.8 bpm) measures were significantly different (p < 0.05) compared to measures of immediately post cycling (44.8 ± 13.7 cm/s; 118.3 ± 17.2 bpm), post-15 min. (50.1 ± 15.0 cm/s; 80.1 ± 12.0 bpm) and post-30 min. (52.7 ± 18.1 cm/s; 73.9 ± 11.9 bpm). SBP measures were significantly different (p < 0.05) at immediately post (118.2 ±17.0 mmHg) compared to post-15 min. (108.1 ± 13.6 mmHg). Resting SpO2 (98.2 ± 1.3 %) measures were significantly different (p < 0.05) compared to measures immediately post (96.5 ± 1.1 %) and post-15 min. (96.9 ± 1.2 %). This study indicates that LE blood flow velocity was increased, and HR was elevated following a single bout of high-intensity LE cycling up to 30 min.-post. Additionally, SBP was elevated, while SpO2 dropped following a bout of exercise to 15 min.-post activity.