HEAVY GOING: The Tuesday morning practice lasted two hours and 20 minutes, the Lions' longest session in the first four days of training camp."This is the time of camp where they're very tired, heavy-legged," Mariucci said. "The practices are a little bit longer right now. To push through these is very good."When we come out of these next few days we should start getting our legs back, but this was one of our longer practices of the training camp."Running back Kevin Jones was held out of part of the morning workout."He was getting a little tight so I kept him out for part," Mariucci said. "That's expected, and we usually get more tight legs with youngsters than we do with veterans. He started getting tight so, as a precaution, we held him out of the rest of practice and let the other guys practice."