Diana is working out hard today under the strict supervision of a demanding personal fitness coach. Her muscles are burning intensely, but her trainer always pushes her to finish every single set. Diana starts her lower body training by performing fifteen repetitions of the classic barbell squat. Her legs feel incredibly heavy, but she keeps her back completely straight to protect her spine. Next, the coach orders her to walk across the room doing a long and deep walking lunge. After that, Diana moves to the metal bar on the wall to try a difficult pull up. She can only complete a few repetitions before her arms lose their strength and fail. To train her chest, Diana lies down on the flat bench to perform a heavy bench press. Finally, she stands in front of the mirror to complete her routine with a slow bicep curl. Diana finishes her day with a two-minute isometric plank on a soft floor mat to strengthen her core muscles.