Lopez, Marcos G.

We examined the reproducibility of the hyperemic response to ischemic exercise (IE) in the forearm and compared the magnitude of this response to ischemia alone (reactive hyperemia, RH). Eight subjects (6M/2F; 26 ±1 yrs) performed 3 trials of IE and 2 of RH. IE consisted of 5 min of forearm ischemia with rhythmic forearm exercise (20% of max) during the final 2 min. RH consisted of 5 min of forearm ischemia. Peak and total (area under the curve) forearm blood flow (FBF; venous occlusion plethysmography) and blood pressure (MAP; Finometer) were measured for 3 min after each stimulus. Forearm vascular conductance (FVC; ml/100ml/min/mmHg) was calculated from FBF (ml/100ml/min) and MAP (mmHg). The mean intra‐individual coefficient of variation (CV) across the 3 IE trials was 13.0±1.4% and 16.3±1.2% for baseline‐adjusted peak FBF and FVC, respectively. The CVs for total FBF and FVC were 10.4±1.0% and 14.9±1.0%, respectively. Mean peak FBF was greater for IE compared to RH (37.3±2.7 and 30.0±1.3, P < 0.002), however mean peak FVC was not different (35.1±2.6 and 34.5±1.1, P = 0.80). Mean total FBF (67.6±3.9 and 18.0±2.5, P < 0.001) and mean total FVC (64.7±2.7 and 20.8±3.2, P < 0.001) were greater for IE compared to RH, respectively. Thus, our data suggest that the hyperemic response to IE is reproducible, and that the magnitude of this response is greater than that of ischemia alone. NIH HL‐46493 (MJJ), CTSA RR‐024150 and RR‐024152