Millennials are trending toward living healthier lifestyles each day, but this is much harder than it appears, especially with the large amount of disagreement among workout enthusiasts. With nearly everyone claiming that they’ve discovered “the secret,” how is one to know whom to trust? The harsh reality is that the right workout plan is different for each individual, but quantitative data can provide a strong starting point. The objective of this project is to observe the effects of changing variables involved with workouts on one-repetition maximum lifts (the maximum weight that can be lifted for only one repetition while maintaining correct form). The variables manipulated were heart rate (at the end of the workout), total workout time, and the number of moves related to the main muscle group for the workout. Data was collected on a daily basis, five days a week for two semesters, with each day comprising one of the five main muscle groups: arms, shoulders, legs, chest, and back. With the data collected, an analysis with pivot tables in Microsoft Excel and a predictive model in IBM’s SPSS Modeler provided the basis for the best underlying core structure of a one-repetition-maximum-increasing workout plan.