Burning Thighs is an Odd Job in Chapter 9, "The Town That Never Sleeps", in Final Fantasy VII Remake, taking place in Wall Market. Either Madam M or Chocobo Sam (depending on quest line) asks Cloud Strife to speak to Jules at the gym, while Aerith Gainsborough is given a dress.
Regardless of if the player received a quest line from Chocobo Sam (including "The Party Never Stops"), or from Madam M (including "The Price of Thievery"), "Burning Thighs" will appear. The quest that follows depends on which questline is taken (either "A Dynamite Body" for Chocobo Sam, or "Shears' Counterattack" for Madam M), but "Burning Thighs" must be completed alongside the other to unlock it.
To perform a squat, follow a clockwise movement of button presses: , , , and , matching the rhythm on-screen, and matching Cloud's successful movements. On-screen prompts vanish after a few squats, after which the player must simply get into the rhythm, which speeds up over time. Pressing a button too fast before Cloud finishes a motion, or pressing the wrong button, causes Cloud to stumble, losing time. The goal is to achieve more squats than the opponent, and not to achieve a certain number.
If Cloud gets more squats than Ronnie, the sidequest is completed, and Cloud obtains three mega-potions. However, Cloud can challenge different characters for different awards.