The effect of exercise training on body weight and peptide hormone patterns in normal weight college-age men

Resting and peak glucose, insulin, glucagon, gastric inhibitory polypeptide (GIP) and pancreatic polypeptide (PP) levels were evaluated pretraining, 3 weeks and 10 weeks posttraining in seven college age males. The exercise consisted of thrice weekly session of jogging at 70% VO2max for 20 minutes plus warmup and cool down. Following the 10 weeks, VO2max increased significantly. Body weight remained constant and body fat decreased significantly. Fasting and peak blood glucose levels were normal at the beginning of the study yet improved with training. As expected, fasting and peak insulin levels decreased significantly with training. Although GIP did not change significantly with training, an uncoupling of GIP and insulin peak responses was observed. Glucagon levels were essentially unchanged. Fasting and peak PP levels increased slightly as training occurred. These hormone responses suggest that perhaps body weight and/or changes in body fat stores and fuel use might influence peptide hormone responses with training.