It is well-known, that the dog is in the habit of concrete man. The dog understands and obeys him. But there are other demands in sport. The dog mustn t have fear of the unknown people, and one can replace the owner during competitions. In this case correct behaviour line is the absence of fury and dictation during first trainings.
Excessive severity can leads to nervous state of the dog, and it can be frighten.
All dogs like active movements, and they take part in sports games with pleasure, but for example large, heavy dogs breed are not suitable for agility. You can train them on agility trace, but they hardly can have nice results. The same is for mini-agility class. Competitions on hurdle negotiations for a speed are very popular in some countries. And up to 400 dogs can take part in it.