I OWN 6 PAIRS OF FITFLOPS.  THEY REALLY DO TONE THIGHS, CALVES AND GLUTES. I WEAR THEM ALL YEAR ROUND, AS I USE ONE PAIR FOR SLIPPERS IN THE HOUSE.  THIS PIETRA STYLE IS VERY ATTRACTIVE, AND I GET COMPLIMENTS ALL THE TIME, AS WELL AS QUESTIONS AS TO WEAR I GOT THEM. I ALSO HAVE THEM IN BLACK.  I NORMALLY DON'T WEAR FLIP FLOPS BECAUSE THEY HAVE NO ARCH, AND NO SUPPORT THEREFORE NOT A GOOD CHOICE FOR ME.  WITH THE FITFLOP BRAND, YOU GET A SUPPORTED ARCH, HEEL SHOCK ABSORBER, AND COMFORT,PLUS THEY MAKE YOU LOOK GREAT. I BELIEVE THE ARE RECOMMENDED BY PODIATRY ASSOCIATION.