Sports already practice quite a bit and for a long time I can not even begin to imagine how stressful it would be on the players and athletes if they practiced even longer. Most of the individual players never really stop practice as well, they will work out in their free time and train on their own.
The question does not give enough information to provide an adequate response. What type of sport? In what venue, (professional, college, high school)? In which country? In America, football is by far the most popular sport, and professional football players practice 5 days a week, at least 40
hours a week. More if they are personally motivated. In Mexico they take that soccer thing way too far to the point of self-destruction and violence.
The decision to practice more in sports is personal. Most sport directors maintain a minimum requirement of all its players, regardless of the sport or country. However, if someone feels that they need to practice more, to be better at their sport of choice, then that is their personal