Editor’s Note: The following article is one in a series of pieces inspired by spring being a time to take charge of our health. They all include tips for being fit, eating right and feeling healthy, brought to you by Colgate. Let’s ToneUP together!

Just as fashion, hair, and makeup trends cycle through the seasons, women’s beauty and fitness ideals constantly evolve—reflecting the social and economic climate of the times. Looking back over the last half-century or so—as women gained social and financial power—iconic beauties increasingly project feminine strength. And while the womanly physique has occasionally taken a backseat to waifish androgyny—voluptuous curves never truly go out of style. 

During World War II, Betty Grable (also known as The Girl With the Million Dollar Legs) boosted the troops’ morale during World War II with her saucy swimsuit pin-up, showcasing those shapely gams (nothing like the stick-thin models who have teenage girls obsessing over the “thigh gap” today). She perfectly embodied the Rosie the Riveter, can-do, keep the homefires burning attitude of the ‘40s.

The va-va-voom hourglass figure, epitomized by Marilyn Monroe’s wiggle and Sofia Loren’s décolletage, ruled the prosperous, post-war ‘50s when women left the factories and began focusing on creating a home and making babies. 

As the ‘60s rolled around, robust images of bombshells like Raquel Welch sporting an animal skin bikini in One Million Years B.C. and Jane Fonda cavorting through space as Barbarella provided a healthy counterpoint to pin-thin supermodel Twiggie.

By the ‘70s, television was a fixture in most living rooms and the small screen brought a new crop of athletically sexy action stars. Charlie’s Angel, Farrah Fawcett’s all-American surfer girl sportiness presented a more attainable beauty ideal. While Lynda Carter’s Amazonian, bustier-clad Wonder Woman was all fantasy.

Read Related: Olympic Boxer & Face of CoverGirl: Marlen Esparza Inspires

Style chameleon Jane Fonda completed her metamorphosis from baby bombshell to toned aerobics aficionado when she released her first Jane Fonda Workout video and started a fitness revolution in the ‘80s. Toned, lean muscularity, big hair, and power suits edged out curves and push-up bras as women gained workforce equality and cracked the glass ceiling. Madonna took it to the next level with a chiseled bod and bondage-esque bullet bra corsets—exuding aggressively powerful sexuality.

With any revolution, there’s always a backlash and the fin de siecle ‘90s  saw oversized grunge flannel and heroin-chic cover girl Kate Moss driving teen girls to crash-diet and downplay their natural assets. Luckily this phase was short-lived.

When the stunningly voluptuous Jennifer Lopez made her film debut in Selena and unapologetically flaunted her now famous curves on various red carpets, she ushered in a beauty paradigm for the new millennium—borrowing a little something from each preceding decade. 

J.Lo is athletic, super-fit and voluptuous. She’s pure glam but still Jenny from the Block. She was born and raised in the Bronx but celebrates her Puerto Rican roots. She’s a film goddess, a pop star, a business woman, a mom, and at over 40 looks better than ever.

Today’s beauty and fitness icons come in more shapes, sizes, and colors than ever before. What they all share is strength, confidence, and a healthy attitude about staying in shape while appreciating a few extra pounds here and there.

Venus and Serena Williams—tennis powerhouses and fashionistas. Eva Longoria striding confidently onstage at the 2005 MTV VMAs wearing only a plunging swimsuit and heels. Women’s boxing pioneer and face of Covergirl Marlen Esparza. Gorgeous and talented moms Halle Berry, Beyoncé, and Jessica Alba. Down-to-earth twenty-somethings Mila Kunis and Jennifer Lawrence. All of these amazing women embody what it means to be fit and beautiful in 2013.