In the past I've been training a lot and done pretty well. I've managed to become a national champion in two different sports at the same time. Besides that I've always managed to do pretty well in most of the competitive sports I set my mind to.
When it comes to bicycle training, I usually disagree with most riders, who usually think that as long as you train 100 - 200 km a day you're going to do pretty well. I've been there too and yes, I managed pretty well. But the big boost came after changing my diet, training and especially stretching routines after talking to a sports physician.
At my peak I developed 4 week programs on my own, which is challenging, but not impossible. I will try and give you an example at the bottom of this article.
On the internet you can find many links and pages with information on how to check your fitness. I have decided to translate the ones I have and still use while training. Please keep in mind, that these tests aren't a 100% accurate. This is due to the fact that the more you train, the better you know how to plan your run/race. What this actually means is that you are not giving it a 100% all the way. In order to have a reliable fitness number, you need to contact a sports laboratory that has the necessary equipment.
Be warned, the test is pretty tough, been there - done that.