This study examined the effects of feeding a liquid meal during weight training on selected hormones and substrates. Ten male subjects were given a meal (MW) or nonnutritive placebo (W) before and intermittently during a 2-hr weight training session, and a meal before and intermittently during 2 hours of rest (M). Serum insulin increased from 12.2 ± 1.2 and 11.2 ± 1.3 before feeding to 37.2 ± 4.8 and 45.0 ± 5.0 mU · ml1 during exercise in MW and M, respectively, and remained elevated for 120 min. Insulin remained at resting levels in W throughout the experiment. Glucose increased from 5.20 ± 0.16 and 4.82 ± 0.20 before feeding to 6.23 ± 0.30 and 6.0 ±0.36 mmol 1−1 at the beginning of exercise in MW and M. Glucose declined during the first 15 min of exercise in MW and M but remained at or above resting levels for 120 min in MW. Lactate increased above 5.9 mmol · I1 in W and MW during exercise. Glucagon remained unchanged in all groups. Perceived exertion during exercise was 8.5±0.16 for MW and 8.3±0.18 for W. Feeding a liquid meal before and during weight training exercise can increase serum insulin and maintain blood glucose for a prolonged period.