(Bloomberg Businessweek) -- Novak Djokovic, age 35, sometimes hangs out in a pressurized egg to enrich his blood with oxygen and gives pep talks to glasses of water, hoping to purify them with positive thinking before he drinks them. Tom Brady, 45, evangelizes supposedly age-defying supplements, hydration powders and pliability spheres. LeBron James, 38, is said to spend $1.5 million a year on his body to keep Father Time at ba...