Gwen Stefani, 44, often pairs her bikinis with long fluid skirts (as seen here) to hit the California beaches with her young sons—not that the fit singer had anything to hide! Gwen, who will turn 45 on October 3, is worshipped for her tight abs and fit shape. But when it comes to working out, Gwen is never “just a girl.” She says that she works out “more like a man” and is not into Pilates or yoga. When Gwen hits the gym, she spends her time weight lifting, boxing, or doing serious cardio. But there is another reason why Gwen looks so great in a bikini in her 40s: She works out five days a week and make sure to concentrate on abs each time.