One and Done Workout Reviews – Is It Legit? Worth the Money? One and Done Workout by fitness guru Meredith Shirk features a simple 7-minute S.I.T. strategy that can activate natural metabolic multipliers to produce enhanced results, but is it worth it or are there negative consequences of using the One & Done Workouts? April 22, 2021 23:37 ET | Source: Marketing By Kevin Marketing By Kevin Homewood, Illinois, UNITED STATES Chicago, IL, April 22, 2021 (GLOBE NEWSWIRE) -- The One and Done Workout is a fitness program that takes very little time each day for impressive results. Users only have to engage in the regimen for two weeks to see a change in the way that the body feels and looks.