Does sinusoidal leg cycling exercise period affect brachial artery blood flow dynamics and forearm skin blood flow in humans?
Brachial artery blood flow response to leg cycling exercise shows an anti-phase dynamic that does not always reflect downstream forearm skin blood flow.
PURPOSE: To quantify the dynamics of blood flow in brachial artery (BF-BA) in response to sinusoidal work rate (WR) leg cycling exercises of 2-, 4-, and 6-min periods and to examine their relationship with the forearm skin blood flow (SBF). METHODS: ). We continuously measured pulmonary gas exchange, heart rate (HR), blood velocity and cross-sectional area of BA, and forearm SBF and sweating rate (SR). RESULTS: and HR with WR forcing were similar (e.g., phase shift (θ) in HR °: 2 min, 60 ± 7; 4 min, 45 ± 10; 6 min, 37 ± 8; mean ± SD) to previous study results, that is, a longer period showed a shorter θ and larger amplitude of responses. Contrarily, the BF-BA response showed anti-phase (approximately 180°) regardless of the period, whereas the θ of forearm SBF and SR were similar to gas exchange and central circulation. CONCLUSIONS: -delivery to active muscles and thermoregulation. The response of BF-BA seems to not always reflect the response of forearm SBF in the downstream area.
Miura et al. (Wed,) studied this question.