The purpose of this series of studies was to use a practical measure to examine the course of muscular endurance recovery after 3 sets to failure in 10 men (ages 18 to 30 years) and then compare those results with 10 men (ages 18 to 30 years) who performed 7 sets and 10 older men (ages 50 to 65 years) who performed 3 sets. Recovery as indicated by number of repetitions performed was observed at 24, 48, 72, and 96 hours. Repeated-measures ANOVA was used to investigate differences in recovery over time. For group means, performance was significantly lower in all 3 groups after 24 hours (p< 0.05). At 48 hours, performance of the groups was not significantly different from baseline (p> 0.05). Number of repetitions performed at 72 hours was significantly higher than that in session 1 (10.2+/-1.4 reps in session 1 vs. 11.2+/-2.3 at 72 hours, p= 0.022) in the young 3-sets group, but not in the other groups. After 96 hours, only the young 7-sets group was found to be performing at a level approaching significance (10.3+/-1.2 reps in session 1 vs. 11.1+/-2.0 at 96 hours, p= 0.051). No significant difference was found between the young 3-sets and 7-sets groups at any time (p> 0.05). The young 3-sets group was found to be performing at a significantly higher level than the older group at 72 hours (11.2+/-2.3 reps in the younger vs. 9.9+/-1.7 in the older group, p= 0.008), a difference that also approached significance at 96 hours (p= 0.06). Large intersub-ject variability was observed at all time points. The results suggest that individual recovery testing before exercise prescription is practical, and this protocol may be sensitive to differences in training volume and subject age.