Note: Obviously the value of being a training business franchisee will depend on many factors. What follows is a very personal opinion on training franchise "opportunities". Your results may vary.
Here's the short answer. No!
On the surface of it, it would seem that purchasing a training franchise makes sense, since you get ready-made products and services to sell, some level of training in selling and deliverying those products, and in some cases, you get to represent a "name" in the field that has significant brand recognition (for example, Brian Tracy, Dale Carnegie).
You should know, though, that for many training, coaching or consulting franchises, your primary function is going to be selling the products and services developed by others. You will be doing so in ways similar to all other franchisees associated with the company. If you browse franchise opportunities in training or training-related fields, one of the few "requirements" companies ask for is the ability to sell. Some major companies claim that you need zero training skills, but will ask for selling skills.
Is that what you want to do?
If so, then this may work.
You also need to consider the start-up costs. Franchise fees are often substantial and startup fees are quite high, making it difficult to "get in" if you lack the capital. Since you have a signficant financial investment going in, there's a tendency to focus on quantity of business, rather than quality, and as a result many franchise holders end up using sales practices that detract from their businesses over the long haul.
In my experience as a training purchaser, I've found that trainers who are franchise owners become one trick ponies, selling their particular services even when they don't fit customer needs, lack the ability to determine customer needs, tend to rely on slick sales and brochures, and give the impression that their knowledge and abilities are simply quite superficial. Much of this makes sense when you understand how franchising works, the limited training offered, and the need for franchisees to get out of the financial hole created by their initial investments. The franchise system pushes people into certain behaviors that may not be sustainable over the long haul.
If all you want is "a training business", then perhaps franchising will work for you, at least for a while. However, if you already have training skills, and instructional design skills and consulting skills, I'd suggest that you save the money, continue to develop and grow, and use a training business model based on your own strengths and abilities. Use the money you would spend to buy a training franchise to market your own business, or pursue more formal training.
One final point: If you are going to pursue purchasing a training franchise, RESEARCH EXTENSIVELY.