Nutritional Prevention of Exertional Muscle Dysfunction

The investigators want to find out whether a choline supplement can protect muscle health in young men with very common genetic vulnerabilities. Men, who respond to a brief, but intense set of arm exercise and have a common genetic profile, will be asked to use a choline supplement for three weeks and a placebo for three weeks. Before the begin of the supplementation study and after 3 and 6 weeks the investigators will test response to the exercise challenge and ask that all consumed foods are recorded.