The Effect of Two Exercise Training Methods on Growth and Differentiation Factor 11 (GDF11) and Muscle Mass Regulation in Older Rats

Growth and differentiation factor 11 (GDF11) is a protein with anti-aging potential and may play a role in regulation of skeletal muscle mass. However, to date little is known about the effect of exercise training on it. Therefore, in this study, using 24 aged male Wistar rats, the effect of eight-week resistance and aerobic training on GDF11 levels in tibialis anterior (TA) muscle was investigated. The resistance training protocol included 10-15 reps of ladder climbing with a resistance (attached to their tail base) equal to 55-85% of their maximum carrying capacity, 3 sessions per week), and the aerobic training protocol included 30-45 minutes of swimming exercise with a weight equal to 3-6% of their body weight (attached to their tail), 4 sessions per week. One way analysis of variance was used to test the difference between group  (α < 0.05). The result showed that resistance and aerobic training increased TA muscle levels of GDF11 by 5.3% and 1.6%, respectively. Moreover, resistance and aerobic exercise led to an increase of 9.5% and 4% in TA muscle mass, respectively. However, the amount of changes was not statistically significant in either case (p>0.05). Based on the findings of the present study, especially those of resistance training, it seems that GDF11 is involved in exercise training-induced upregulation of skeletal muscle mass in aged rats.