A follow-up study of 1 year was performed on 11 male elite weight lifters. Several parameters including training volume, weight lifting performance, and serum hormone concentrations were measured during seven test occasions. In addition, the same measurements were repeated three times during a 6-week period preceding the primary competition, which took place about 5 months after beginning of the follow-up. The primary findings were observed during the 6-week period from which the first 2 weeks of stressful training was associated with significant decreases (P less than 0.01-0.001) in serum testosterone concentration, in testosterone/cortisol and in testosterone/SHBG ratios, and with a significant (P less than 0.001) increase in serum LH concentration. The individual changes during the stressful training in serum testosterone/SHBG ratio were related (r = .63; P less than 0.05) to the individual changes in the weight lifting result in the clean and jerk lift. During the following "normal" 2-week and reduced 2-week training periods, the concentration of serum testosterone remained unaltered, but serum cortisol and serum LH decreased significantly (P less than 0.05-0.01). During these periods, the serum testosterone/SHBG ratio increased (P less than 0.01). The individual changes during this preparatory 4-week training before the primary competition in serum testosterone/SHBG ratio and the individual changes in the weight lifting result in the clean and jerk lift correlated significantly with each other (r = .68; P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)