The purpose of this echocardiography study was to measure peak coronary blood flow velocity (CBV_peak) and left ventricular function (via tissue Doppler imaging) during separate and combined bouts of cold air inhalation (−14 ± 3°C) and isometric handgrip (30% maximum voluntary contraction). Thirteen young adults and thirteen older adults volunteered to participate in this study and underwent echocardiographic examination in the left lateral position. Cold air inhalation was 5 min in duration, and isometric handgrip (grip protocol) was 2 min in duration; a combined stimulus (cold + grip protocol) and a cold pressor test (hand in 1°C water) were also performed. Heart rate, blood pressure, O₂ saturation, and inspired air temperature were monitored on a beat-by-beat basis. The rate-pressure product (RPP) was used as an index of myocardial O₂ demand, and CBV_peak was used as an index of myocardial O₂ supply. The RPP response to the grip protocol was significantly blunted in older subjects (Δ1,964 ± 396 beats·min⁻¹·mmHg) compared with young subjects (Δ3,898 ± 452 beats·min⁻¹·mmHg), and the change in CBV_peak was also blunted (Δ6.3 ± 1.2 vs. 11.2 ± 2.0 cm/s). Paired t-tests showed that older subjects had a greater change in the RPP during the cold + grip protocol [Δ2,697 ± 391 beats·min⁻¹·mmHg compared with the grip protocol alone (Δ2,115 ± 375 beats·min⁻¹·mmHg)]. An accentuated RPP response to the cold + grip protocol (compared with the grip protocol alone) without a concomitant increase in CBV_peak may suggest a dissociation between the O₂ supply and demand in the coronary circulation. In conclusion, older adults have blunted coronary blood flow responses to isometric exercise.