Yes, Alexandra Paul is 50 but Pamela Anderson is 46. The 4 years age difference is erased when you realize that Anderson has been receiving treatment for Hepatitis C since 2003 (and will always require treatment) whereas Alexandra Paul regularly competes in endurance events and in June 2012 swam the 12.5 miles around Key West in under 5.5 hours.
Alexandra has also raced the Maui Channel Crossing (10 miles from Lanai to Maui), the Fiji Swim in 2009 (an 11 mile open ocean race from Fiji to Beachcomber Island), and the Bonaire Island ocean race. Plus she has completed the Hawaii Ironman race twice as well as the Chicago Triathlon, and many others.
Paul has also done the Boston Marathon, the LA Marathon, the Rock N Roll Marathon, the Chicago Marathon, several other marathons, in addition to a multitude of shorter runs, bike rides, and swims.