Paradoxical Advantage of Middle Aged Sedentary over Young Sedentary on Starting Exercise in Terms of GH/IGF-1 System

The aim of this study was to investigate the effects of the submaximal running exercise on the GH/IGF-1 axis in the middle aged sedentary non-obese and pre-obese males. Twenty-four healthy volunteer males were divided into two groups and then two subgroups according to their age ranges (20-25 and 35-43) and Body Mass Indexes (BMI) (non-obese - NO and pre-obese - PO) respectively. All subjects underwent a submaximal running exercise for 30 minutes a day / 4 days a week and for a period of 6 weeks. Serum GH, IGF-1, IGFBP-3, and insulin levels were measured in all subjects before and after the exercise program. IGFBP-3 levels were significantly decreased in the PO middle aged and NO young groups whereas IGF-1 levels were statistically increased in NO young group after the exercise treatment. Contrary to the results observed in young people, middle aged PO and NO groups had a tendency to have better insulin and GH responses to exercise. In the light of the findings, it could be suggested that the middle aged group’s response to exercise on the base of GH/IGF-1 system was more advantageous than the young group, although it is not significantly important.