BA vasodilation (A), shear rate (B), and the contribution of nitric oxide (NO) to BA vasodilation (C) during progressive handgrip exercise. The contribution of NO to BA vasodilation was determined by the following equations: 1) NO contribution in control = ΔBAdiameterControl − ΔBAdiameterL-NMMA and 2) NO contribution in AA = ΔBAdiameterAA − ΔBAdiameterL-NMMA+AA. Absolute changes from baseline (BL) are presented for BA vasodilation and shear rate, and % change in BA diameter is expressed on right y-axis in A. Resting BL without (BL) and with infusion (BL infusion) is documented for each condition. All variables exhibited significant intensity-dependent increases during handgrip exercise (symbols denoting significant increases across workloads are not included for clarity). Values are means ± SE. *Significant difference between control and l-NMMA, #significant difference between control and AA, †significant difference between AA and l-NMMA + AA (P < 0.05).