Hiring a coach helps with four things:
• It accelerates the learning curve, helping you to learn good technique and proper training practices from the beginning.
• It saves money. This may seem counterintuitive to save money by spending money, but learning to do something more quickly and effectively ultimately saves time and money.
• It provides objective feedback. No more second guessing yourself as to whether you're doing too much or too little. You'll also have the benefit of a sounding board for questions.
• It provides accountability. It's difficult to slack off or procrastinate when a third party is involved.
Source: Why You Need a Coach
Hiring a coach can make the world of difference—not only with planning workouts, but also with keeping you motivated…almost all triathletes can benefit from having a coach.