Forearm blood flow responses. Reactive hyperemia forearm blood flow was assessed using venous occlusion plethysmography 120 min after ingestion of whey peptide (NOP-47) Placebo. At each time point, reactive hyperemia induced forearm blood flow was assessed after 5 min of upper arm occlusion. Recovery of reactive hyperemic blood flow was determined after blocking the venous efflux of the upper arm for 7 sec during each of 8 subsequent 15-second cycles. Significant differences between NOP-47 and Placebo (*P < 0.05).