Resistance training increases and protein intake does not influence skeletal muscle aPKC zeta/lambda content in older men and women

To assess the effect of resistance training (RT) and protein intake on skeletal muscle insulin signaling protein contents in older people, 14 men and 15 women (BMI 26 ± 1 kg/m 2 ; 61 ± 1 yr; mean ± SEM) completed a 12‐week dietary and RT intervention. They consumed either 0.9 (LP) or 1.2 g protein·kg −1 ·d −1 (HP) and completed RT 3x/wk. With RT, body weight remained stable, fat‐free mass increased and fat mass decreased independent of diet and gender (change from baseline: 2.03 ± 0.51 kg, −1.20 ± 0.45 kg, respectively P < 0.05). Glucose tolerance, assessed with a 75g oral glucose tolerance test, improved with RT. Glucose area under the curve decreased independent of diet and gender (−26%: 3833 ± 330 to 2840 ± 290 mg·dL −1 ·2hr −1 , P < 0.05). Insulin and C‐peptide responses differed between diets; both decreased in LP + RT (−21%: 4987 ± 587 to 3956 ± 513 mu·L −1 ·2hr −1 ; −14%: 179120 ± 20782 to 154648 ± 17023 pmol·L −1 ·2hr −1 , P < 0.05) and were unchanged in HP + RT. Vastus lateralis insulin receptor, insulin receptor substrate‐1 and Akt contents were unchanged. Atypical protein kinase‐C (aPKC) zeta/lambda content increased 56% with RT independent of diet and gender (P < 0.05). The increase in aPKC zeta/lambda was not correlated with changes in body composition or whole body glucose metabolism (P > 0.05). These results indicate that resistance training alters a portion of the skeletal muscle insulin signaling pathway in older people, and protein intake does not influence this change. Support: Am Egg Board – Egg Nutr Ctr