Effects of muscle strength and aerobic training on basal serum levels of IGF-1 and cortisol in elderly women

The aim of this study was to compare the effects of muscle strength and aerobic training on the basal serum levels of IGF-1 and cortisol in elderly women. The subjects were divided in three groups as follows. 1. Strength training group (SG) submitted to the weight training called 1-repetition maximum test (1-RM, 75-85%). This group contained 12 subjects of mean age = 66.08 +/- 3.37 years; and body mass index (BMI) = 26.0 +/- 3.72 kg/m(2). (2) Aerobic training group (AG) submitted to aquatic exercise; they were 13 subjects of the mean age = 68.69 +/- 4.70 years; and BMI = 29.19 +/- 2.96 kg/m(2). (3) A control group (CG) of 10 subjects, of mean age = 68.80 +/- 5.41 years: BMI = 29.70 +/- 2.82 kg/m(2). The training periods were 12 weeks, Fasting blood was analyzed to measure lGF-1 and basal cortisol levels (by chemiluminescence method), both at the beginning and the end of the intervention. Student's t-test revealed increased IGF-1 in the SG (p < 0.05) compared to the other two groups. Repeated-measure ANOVA showed also elevated IGF-1 (p < 0.05) in the SG compared to the other groups (AG and CG). There were no differences in cortisol levels. In conclusion, high-intensity training caused changes in IGF-1. This suggests that strength training may provoke anabolic effects in elderly individuals. (C) 2008 Elsevier Ireland Ltd. All rights reserved.