There are still a lot of fighters competing in the "over 40" club and having success.
Bernard Hopkins, at 48 years old, is still fighting at the top level and is getting ready to fight the IBF light heavyweight champion Tavoris Cloud in March.
44-year-old Glen Johnson, meanwhile, just lost to George Groves in December and Antonio Tarver, also 44 will fight again as soon as his suspension is removed, and these guys can still compete at world level.
However, Roy Jones, Jr, 44, is rumoured to be fighting 48-year-old Steve Collins next and that is probably a good bout for him because he really doesn't belong at world level anymore.
Former WBA, IBF and WBO lightweight champion Nate Campbell, 40, beat Juan Diaz in March 2008 when he was 36. He was one of the older champions at that point and was still competing at the highest level.
Bizier looked good and totally controlled the veteran and will now move towards a world title challenge.
Quotes of the week
He defended his belts once then moved up a division to light welterweight and had a no contest with Timothy Bradley when the fight was stopped due to cuts after three rounds.
Campbell didn't look like himself in that fight and even though Bradley dominated, maybe age caught up on him; he had four losses in his next five fights against good opposition but Campbell was still competing well at world level and was just a step behind most of the younger guys.
Campbell was coming off two wins against decent opponents and last week he faced undefeated Canadian Kevin Bizier who had a record of 19-0 (13 KOs) for the NABA welterweight title. This was a step up in class for 28-year-old Bizier, who had been a welterweight or higher since he turned pro.
It was clear from the start that Bizier was the bigger man and his opponent's body was looking a little soft and Campbell used his awkward style of turning his body around to give Bizier a smaller target to hit.
Bizier held his hands high as he came forward using a good left jab to get in close so that he could unload with his punches, but in the first few rounds, Campbell was using his experience. He wanted Bizier to make mistakes but he didn't.
Bizier was the busier fighter round after round, even though Campbell was still in the fight. Bizier picked his punches well in the fourth and hurt Campbell with a clean left hook to the body but Campbell fought back.
A big left hook to the head by Bizier in the sixth hurt Campbell and even though the veteran fought back, the younger Bizier was getting faster and stronger. Campbell was making him work hard and was moving his head well so that Bizier wouldn't have a steady target to hit.
But from the seventh round onwards, Bizier started to land a lot of shots. And Campbell didn't come out for the ninth; he claimed his back was hurting and he couldn't go on.
Bizier looked good and totally controlled the veteran. Now he will move forward for a world title challenge.