The study was renewed in September 1997 to perform analyses of the data collected under Phase I. A series of nongenetic studies were undertaken on the dataset. Physiological, behavioral, and social determinants of maximal and submaximal indicators of cardiorespiratory endurance in the sedentary state and in the response to training were investigated taking into account the contributions of age, gender, and race. Similar analyses were conducted on the cardiovascular disease and non-insulin dependent diabetes mellitus (NIDDM) risk factors monitored in the study. Genetic analyses determined the heritability levels and tested for paternal or maternal effects, major gene effects, and segregation patterns which were used to develop hypotheses concerning genetic bases of the response to endurance exercise. A panel of candidate genes were typed and used for association and linkage studies. Differential display analysis of skeletal muscle transcripts were used to identify new candidate genes for the response to endurance exercise. Finally, a genome wide search was undertaken to isolate candidate genomic regions and positional candidate genes for the response of cardiorespiratory endurance and cardiovascular and NIDDM risk factor phenotypes.