It is easy to see why a person might want to buy a product to make their fitness training more effective. There are many products that are very good in one aspect, but not effective in another. If the person is interested in building up their strength, but does not want to take the time and energy out of their workout to train, they would want to use these products. For example, you may want to use the weight training equipment to do squats. However, this is a lot of time and energy for the person to spend, not to mention that it could give them an injury and not be worth it. If you would like to buy a product that is effective in one area of your fitness training, but is ineffective in another, you could buy the product from me . This means that I will do my best to list products that are effective in both areas. There are also products that are useful in one area, but not effective in another. The above is not an exhaustive list. If you have other questions, feel free to ask, I will try to answer as much as I can.