This is what I have found.
Note: You are looking at products from different manufacturers, and therefore some products may not work for you. You will be asked what is wrong in the description, or why you need this product in order to improve your agility. Please don't give me crap about it if it doesn't work. When you first start a new program, it's not so easy to be sure that it works. You will find lots of people giving you crap about their new program, and telling you to just run in whatever way you prefer. This isn't a good idea! You should be getting a new program every three months. The new ones are all going to be different. There are a lot of them, so don't let yourself get used to your current program and start looking at other ones. If you find your current program isn't working for you, then go for another one. If you are doing a low volume program and not seeing results, then maybe you have something wrong with your technique. Or maybe you are just doing something wrong and need to do something about it. That's what I was doing for the last two years of my program.