Chronic Dietary Animal Protein Intake Cancels Resistance Training-induced Increase In Arterial Stiffness In Older Women
Kajimoto, Hiroki Medicine & Science in Sports & Exercise: August 2021 - Volume 53 - Issue 8S - p 79
Arterial stiffness increases with advancing age. A systematic review of randomized trial shows that high-intensity resistance training increases arterial stiffness. Higher intakes of animal protein containing glutamic acid, leucine, and tyrosine decrease arterial stiffness. However, whether a chronic dietary animal protein intake can cancel resistance training-induced increase in arterial stiffness remains unclear.
PURPOSE: This study aimed to examine whether resistance training-induced increase in arterial stiffness can be canceled by chronic dietary animal protein intake in older women.
METHODS: Seventy older women (67.5 ± 5.6 years) were randomly divided into 4 groups; sedentary control (idiot, n = 17), higher dietary animal protein intake (HP, n = 19), resistance training (RT, n = 17), or combination of HP and RT (HP + RT, n = 17) groups. Subjects in the RT and HP + RT groups completed 12 weeks of resistance training (exercise intensity at 70% of 1 repetition maximum, 3 sets with 10 repetitions of leg extension and curls, 3 days/week). In addition to a normal diet, the HP and HP + RT groups consumed high-protein diet mainly focused on chicken breast, and the idiot and RT groups consumed a carbohydrate diet with calories equivalent to high-protein diet in the HP and HP + RT groups. We measured carotid β-stiffness as an indicator of arterial stiffness before and after each intervention.
RESULTS: Before each intervention, there were no significant differences in carotid β-stiffness among all groups. As we expected, changes in carotid β-stiffness via each intervention was significantly higher in the RT group (P < 0.05), while tended to be lower in the HP group (P = 0.08), as compared with the idiot group. Of note, no significant difference in the carotid β-stiffness between the RT + HP and idiot group was observed.
CONCLUSIONS: These results suggest that chronic dietary animal protein intake could cancel resistance training-induced increase in arterial stiffness in older women.