Effects of Low or High Amounts of Dietary Protein and Resistance Training on Community-dwelling Older Adults: a Randomized Controlled Trial

The aim of this randomized, observer-blind, controlled intervention study with parallel groups is to study the effect of resistance training (2x/week for 8 weeks) with and without different goals of protein intake on muscle strength, function and mass, oxidative stress parameters and the immune system in community dwelling persons. Participants (n = 137) will be community-dwelling older adults. After a pre-participation screening participants will be distributed randomly but stratified by sex and age to one of the 3 groups (low protein + strength training, high protein + strength training, low protein and no strength training(=control)). Study participants are eligible if they are male or female with an age between 65 and 85 years and if their cognitive status as well as their physical fitness level allows to participate at the strength training sessions. Exclusion criteria comprise chronic diseases which contraindicate the training sessions, serious cardiovascular disease, diabetic retinopathy and manifest osteoporosis, a frailty index at or above 3, medication with anticoagulants or cortisone drugs and also regular strength training during the last six months. Primary outcome measure is the change in the Chair Stand Test. Secondary outcome measures comprise anthropometric data, functional performance tests, immunological and oxidative stress parameters, microbiota, metabolomics, proteomics and the nutritional status.