I hear some fitness organizations boast that they “never have their clients do the same workout twice,” while other reputable organizations promote using periodization training to create adaptation in the body, followed by the shock of change in the next phase. I get confused over which method is better, or if it’s a combination of the two ideas that works best.
Great advice from everyone above; the essentials of losing weight is the nutrition which is the most important in my mind, cardio & resistance training. As far as “BEST TRAINING METHOD” like most said before you do what works best for that particular client.
BUT I believe when designing a routine you always want your clients to get the most out of each session; so implementing total body exercises, functional exercises using compound muscle groups is key. Challenge yourself to be creative with the combinations of exercises you use working in all three planes of motion in every single workout. I feel most clients benefit most with these kind of routines.
Hope that helps,