The main purpose of this study was to examine the relationships between measures of fitness (estimated VO_2peak and handgrip strength) and forearm vascular function in 55 young (22.6 ± 3.5 years) adults. In addition, this study considered methodological and technical aspects regarding the examination of the venous system using mercury in-Silastic strain gauge plethysmography (MSGP). Forearm venous capacitance and outflow were examined using 5 different (7, 14, 21, 28 and 35 mmHg < DBP) venous occlusion pressures and following a 5 and 10 minute period of venous occlusion. A pressure of 7 mmHg < DBP and a period of 10 minutes venous occlusion produced the greatest (p<0.05) venous capacitance and outflow, without altering arterial indices. Reproducibility of forearm arterial and venous indices were evaluated at rest and following 5 minutes of upper arm arterial occlusion at 240 mmHg on three different occasions within 10 days with ICCC ranging from 0.70 and 0.94. Estimated VO2peak correlated with post occlusion arterial inflow (r=0.54; p=0.012) and resting venous outflow (r=0.56; p=0.016). Lastly, handgrip strength was associated with venous capacitance (r=0.57; p=0.007) and outflow (r=0.67; p=0.001). These results indicate the examination of forearm vascular function using MSGP is reproducible. Moreover, the data shows the importance of careful consideration of the selection of venous occlusion pressure and period when implementing these measures in longitudinal trials. Finally, the associations between fitness and venous measures suggest a link between venous function and exercise performance.