Serum lipids: interactions between age and moderate intensity exercise.

The purpose of this study was to examine relationships between age and selected serum lipids and lipoproteins in women before and after a physical fitness programme. Twenty females 27-59 years of age who had participated in the Purdue University Physical Fitness Programme were selected and placed into one of two groups: "junior" (mean age 34, all under 40 yrs) or "senior" (mean age 50, all over 43). A two way factorial design was used to study differences in serum triglycerides (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDLC), high density lipoprotein cholesterol (HDLC), and the risk ratios TC/HDLC and LDLC/HDLC associated with physical fitness and the eight month physical fitness programme. The ability of the biochemical variables to discriminate between the age groups was investigated using discriminant function analyses. The analyses of variance indicated that although the two age groups were matched on the basis of a multivariate physical fitness score (Ismail et al, 1965) the older group was heavier (p less than 0.05), and had higher systolic and pulse pressures (p less than 0.05). Both groups increased their physical fitness score from pre to post programme (p less than 0.01). No significant age related biochemical differences were noted in the univariate analyses; however, in the discriminant function analyses the biochemical variables significantly discriminated between the two groups before, but not after the programme. A decrease in serum triglycerides was observed in the more highly fit women in each age group. These findings suggest that moderate levels of physical activity may help to counteract some of the undesirable changes in the lipid profile associated with age.