 All participants will be asked to complete on three days 24-hour diet interviews with an online automated program provided by the National Cancer Institute. Participants of the intervention study will also have to be complete interviews on the final three days of the two intervention periods The recruited candidates will do an initial exercise challenge with no intervention, then a second challenge after three weeks with the first supplement randomized choline or placebo, then a third challenge after another three weeks with the complementary second supplement choline if they had placebo first, placebo if they had choline first. 