Strength measurements were administered to 52 men ranging in age from 42 to 83 years, who were then randomly assigned within their respective age group to either the Isometric-training Group (ITG) or to the Control-exercise Group (CEG). At the conclusion of a six-week training program all initial measurements were again administered. No significant differences were found in (1) strength trainability by age group, and (2) in strength trainability by muscle group when the upper-extremity-strength ratios were compared with the lower-extremity-strength ratios. When the initial and final strength scores of the ITG were subjected to a t test for correlated samples, the findings included: (1) the four age groups of the ITG experienced statistically significant gains in strength for six of the eight strength measurements, and (2) as age increased, strength trainability appeared to decrease.