Effects of endurance training on glucose tolerance and plasma lipid levels in older men and women

Abstract

Eleven healthy men and women (63 .+-. 1 yr) participated in a 12 mo. endurance-training program to determine the effects of low-intensity and high-intensity training on glucose tolerance and plasma lipids in older persons. Plasma glucose, insulin and C-peptide concentrations were measured for 3 h after ingestion of 100 g of glucose and the total areas under the respective curves were calculated. Total plasma lipids and lipoprotein concentrations were determined during fasting. Maximal O2 uptake increased 12% during 6 mo. of low-intensity training; a further 18% increase occurred during an additional 6 mo. of high-intensity training. Glucose tolerance, which was normal initially, was not significantly changed after training. The total area for insulin was 8% lower after low-intensity training and 23% lower after high-intensity training, compared with before training. C-peptide concentrations were similarly reduced. Plasma lipid and lipoprotein concentrations were unchanged after low intensity training, but high-intensity training resulted in an increase in high-density lipoprotein cholesterol and a reduction in triglycerides. Older persons respond to prolonged, high-intensity endurance training with an increase in sensitivity to insulin and favorable alteration in their plasma lipoprotein-lipid profile.