Article continues below advertisementJewel is showcasing her incredible fitness transformation.The iconic singer, 51, proudly displayed her toned physique in a mirror selfie posted to her Instagram on Tuesday, September 16. She credited weight-lifting and dedication for her impressive look.Article continues below advertisementSource: @jewel/InstagramThe singer credited lifting, yoga, and hiking for her transformation.Article continues below advertisementWearing a black swimsuit, Jewel flashed a radiant smile while flexing her biceps.