In short, you probably don't need to worry about it. But to explain why: We use a acronym called DASH for training that means Desire Accuracy Speed Habitat. First you build the desire for doing the job. Once you have strong desire you start building accuracy. Once you have about 80% accuracy only then do you worry about speed. The last one, Habitat, means that once you are getting the desire, speed, and accuracy you want then you want to start proofing it in other environments so that it becomes second nature regardless of what is going on.
When you start working on speed you will loose some accuracy. This is ok and normal. You have to realize that at that point speed has become an additional criteria that needs to be rewarded just like accuracy is.
For example when you are working on your weaves, if your dog tries going through faster than they normally do but because they are going fast there footing is different and they miss a pole you must reward that big anyway. If you don't you are telling your dog that it is only important to you that they get it perfect and you don't care that they were trying to be fast.
One common mistake is that people think everything should be fast from the start. When you do this you miss out of training good foundation. When you look at the dogwalk the human thinks "go across it". The dog has to think "load squarely, balance weight to stay on that thin board, run up ramp, stay balanced transitioning to flat top surface, deal with the obstacle wiggling underneath me, transition to the down ramp, exit squarely at the bottom. And that doesn't even take into account things like dealing with you rear crossing or being ahead of or behind the dog. So you can see that there is a lot of what we call foundation work to put work into before you add... oh and run as fast as you can across that thing.
The other common mistake is only rewarding perfection. You must reward your dog for trying sometimes even if it wasn't quite perfect. If you don't you will create a perfectly slow performance.