## 3 Results  
Table 1 show the characteristics of the subjects in 1999. The study subjects had an average age of 75 years and had nearly two diseases each. The average and standard deviation of ADL, IADL, and MNA scores were 0.73 \(\pm\) 2.61, 2.82 \(\pm\) 4.70, and 25.64 \(\pm\) 3.25, respectively. The proportion of study subjects who did not exercise, exercised \(\leq\) 2 times/week,  
exercised 3-5 times/week, and exercised \(\geq\) 6 times/week were 38.42%, 5.77%, 10.20%, and 45.62%, respectively. Table 2 show a multivariate regression analysis of the cross-sectional associations of frequency of exercise, MNA score, and a number of diseases with ADL and IADL scores in 1999. After adjusting for confounding factors, the frequency of exercise (\(\leq\)2 times/week, 3-5 times/week, and \(\geq\)6 times/week) was negatively associated with baseline ADL (\(\beta=-0.7\), \(-0.64\), and \(-0.57\), all \(p<0.05\)) and IADL scores (\(\beta=-0.94\), \(-1.05\), and \(-1.34\), all \(p<0.05\)). The MNA score was negatively associated with the baseline ADL and IADL scores (\(\beta=-0.30\) and \(-0.41\), both \(p<0.05\)). The number of diseases was positively associated with the baseline IADL score (\(\beta=0.24\), \(p<0.05\)). Table 3 show the regression analysis of the associations of changes in exercise status over 4- and 8-year periods, MNA score, and the number of diseases with subsequent ADL and IADL scores. Past exercising was positively associated with ADL (\(\beta=0.81\), \(p<0.05\)) and IADL score (\(\beta=1.30\), \(p<0.05\)) over 8 years. Current exercise and consistent exercise were negatively associated with ADL (\(\beta\) range: -2.36 to -3.34, all \(p<0.05\)) and IADL score (\(\beta\) range: -3.32 to -4.50, all \(p<0.05\)) over 4 and 8 years. The MNA score and the number of diseases were associated with subsequent IADL scores over 4 and 8 years (for MNA, \(\beta=-0.19\) and \(-0.16\), both \(p<0.05\); for the number of diseases, \(\beta=0.17\) and \(0.17\), both \(p<0.05\)). \begin{table}
\begin{tabular}{l c} \hline \hline  & **Values \%/Mean \(\pm\) Std** \\ \hline Gender & \\ Men & 54.74 \\ Women & 45.26 \\ Age (y) & 74.74 \(\pm\) 6.13 \\ Formal education (y) & 4.78 \(\pm\) 4.41 \\ ADL score & 0.73 \(\pm\) 2.61 \\ IADL score & 2.82 \(\pm\) 4.70 \\ Frequency of exercise (times/week) & \\ None & 38.42 \\ \(\leq\)2 & 5.77 \\
3–5 & 10.20 \\ \(\geq\)6 & 45.62 \\ MNA score & 25.64 \(\pm\) 3.25 \\ Number of diseases & 2.21 \(\pm\) 1.75 \\ \hline \hline \end{tabular} Abbreviation: ADL: activity of daily living, IADL: independent activity of daily living, MNA: mini-nutritional assessment.  
\end{table} 
Table 1: Characteristics of study subjects in 1999 (\(n=2932\)). \begin{table}
\begin{tabular}{l c c c} \hline \hline  & **ADL Score (\(n=2790\))** & **IADL Score (\(n=2701\))** \\ \hline \multicolumn{4}{c}{\(\beta\)} & \(p\) & \(\beta\) & \(p\) \\ \hline Frequency of exercise (times/week) & & & \\ None & Reference ** & & \\ \(\leq\)2 & \(-0.70\) & 0.0001 & \(-0.94\) & 0.0004 \\
3–5 & \(-0.64\) & \(<\)0.0001 & \(-1.05\) & \(<\)0.0001 \\ \(\geq\)6 & \(-0.57\) & \(<\)0.0001 & \(-1.34\) & \(<\)0.0001 \\ MNA score & \(-0.30\) & \(<\)0.0001 & \(-0.41\) & \(<\)0.0001 \\ Number of diseases & 0.03 & 0.2830 & 0.24 & \(<\)0.0001 \\ \hline \hline \end{tabular} Abbreviation: ADL: activity of daily living, IADL: independent activity of daily living, MNA: mini-nutritional assessment.  
\end{table} 
Table 2: Multivariate regression analysis of the cross-sectional associations * of frequency of exercise, MNA score and number of diseases with ADL and IADL scores in 1999. Table 4 show the multivariate logistic regression analysis of the associations of changes in exercise status during the 4- and 8 years, MNA score, and the number of diseases with ADL and IADL decline over 4- and 8-year periods. Past exercising was positively associated with ADL decline over 8 years (AOR (95% CI) = 1.71 (1.23-2.38), \(p<0.05\)) and IADL decline over 4 and 8 years (AOR (95% CI) = 1.36 (1.00-1.83) and 2.38 (1.61-3.51), both \(p<0.05\)).