Serena Williams, 39, Shows Off Insanely Toned Legs, Arms, Everything In Multiple Instagrams

• Serena Williams showcased her incredibly toned legs and body in a recent series of behind-the-scenes photos on Instagram.
• The images were taken during her recent photoshoot with Stuart Weitzman.
• The tennis champ's workout sessions include an intense HIIT and weight-training portion.

In case you had any doubts that Serena Williams wasn't still out here killing it on a regular basis, consider them shut down with the tennis champ's latest Instagram photos. The 23-time Grand Slam title winner recently posted a series of #bts shots from a photoshoot that prove her incredibly toned legs, arms, everything are still, well, grand slammin'.

In the images, Serena sports a black bodysuit that accentuates her muscular abs, arms, and quads and a pair of bright red leather high-heel, knee-high boots. The photos were taken during the star's recent photoshoot with footwear company Stuart Weitzman.

"These boots. Are made. For walking," Serena captioned the three-image series.

"Forget the boots🔥That body is perfect🔥," one fan wrote. "THIS WOMAN!" commented another. "🔥🔥🔥 HOT 🔥🔥🔥," still another said.

As you might imagine, the tennis champ works hard for that rock-hard body. In May, she shared some of her workout routine in a video with her sister, Venus, which showed the Williams sisters completing a 30-minute modified yoga routine as a warmup before Serena went off to do some cardio.

A few months later, Serena gave fans an idea of what that cardio could looks like in a July TikTok video that is seriously impressive. In the post, Serena does what looks like a weighted HIIT workout that includes some interval ladder training, ab work with a resistance band, weighted jump squats, box jumps, a casual series of plank variations, and more.

But it's just all in a day's work when you're the GOAT.