Can you get the best out of yourself? Do you know how hard to push yourself and when or even how??
For the vast majority of people the answer to these questions would be a firm NO. The solution- hire a professional! Someone who has the right tools for the job in question. If you had car trouble you would go to a mechanic, boiler trouble a heating engineer, a leaky roof a roofer etc. So, physical health, aesthetics or nutrition, see a Trainer.