That oxygen delivery (O 2 del) is “tightly matched” to metabolic demand is widely accepted based on traditional data analysis using group means. Little consideration has been given to the investigation of inter‐individual differences in this coupling. PURPOSE To determine the degree of inter‐individual differences in O 2 del:metabolic demand coupling in healthy young males. METHODS Eleven recreationally active (271.38 ± 6.74 METS) healthy males (24.18 ± 2.08 yrs) performed rhythmic isometric handgrip contractions at a fixed metabolic demand (1 s: 2 s contraction: relaxation duty cycle, 30 kg force) until failure. Forearm O 2 del was calculated as arterial oxygen content (O 2 saturation via pulse oximeter; [hemoglobin] via venous blood sample) x brachial artery blood flow (BABF; Doppler and Echo ultrasound). Data are mean ±SD. RESULTS BABF in last 30 s of exercise: 478 ±150 ml/min, Coefficient of variation (CV) 31%, individual subject values 249, 589, 465, 317, 475, 412, 391, 420, 700, 739, 499 ml/min. O 2 del last 30 s of exercise: 98 ±30 ml/min, CV 31%, individual subject values 55, 117, 92, 69, 88, 85, 75, 88, 141, 152, 115 ml/min. CONCLUSIONS “Tightness” of O 2 del:metabolic demand coupling varies substantially between individuals. Investigating inter‐individual variation may provide an important new approach to advancing understanding of integrated cardiovascular response support of exercising muscle. NSERC