The Effect Of Resistance And Aerobic Exercise On Plasma Total Pyy And Acylated Ghrelin Concentrations

Abstract

The gut hormones ghrelin (appetite-stimulating) and PYY (appetite-reducing) are involved in the regulation of body weight. Research shows that acylated ghrelin is suppressed and total PYY increases during high intensity aerobic exercise, but there is a paucity of data on resistance exercise. PURPOSE: To assess the effect of treadmill running and free weight resistance exercise on plasma acylated ghrelin and total PYY concentrations. METHODS: 12 healthy males (age 21.2 ± 1.1 y, body mass 74.4 ± 8.3 kg, BMI 23.4 ± 1.6 kg·m−2, VO2max 62.0 ± 6.1 mL·kg−1·min−1, mean ± SD) undertook 3, 8 h trials (aerobic, resistance and control) in a random crossover design. All trials began in the morning after an overnight fast. On the aerobic trial participants ran for 60 min at 68 ± 2 % of VO2max then rested for 7 h. On the resistance trial participants completed a 90 min free weight session performing 3 sets of 12 reps of 10 different exercises at 80% of 12 rep max, then rested for 6.5 h. On the control trial participants rested for 8 h. Venous plasma was taken at 0, 0.75, 1.5, 2, 2.5, 5, 5.5 and 8 h and acylated ghrelin and total PYY concentrations measured using enzyme immunoassay (SPI-BIO and Diagnostic System Laboratories respectively). RESULTS: Acylated ghrelin was suppressed during resistance and aerobic exercise (two-way ANOVA, time P = 0.001, trial × time P = 0.035). Post hoc analysis indicated between trial differences for aerobic and control at 0.75 h and between resistance and control at 0.75 and 1.5 h. After adjusting for multiple comparisons the only difference to remain significant was between resistance and control at 1.5 h. Total PYY increased during aerobic but not during resistance exercise (two-way ANOVA, trial P < 0.01, time P < 0.01, trial × time interaction P = 0.027). Post hoc analysis indicated trial differences between control and aerobic (P = 0.038) and resistance and aerobic (P = 0.028). CONCLUSION: Acylated ghrelin is suppressed and total PYY increases during high intensity treadmill running. Resistance exercise suppresses acylated ghrelin but there is no effect on total PYY.