You feel fine when you're walking around. You can exercise without too much trouble. But then you sit at your desk for half an hour and your lower back starts aching. Or perhaps it's the car. A long flight. Dinner at a restaurant. A night on the couch. Suddenly your back feels stiff, uncomfortable or increasingly painful the longer you stay seated. Sitting-related back pain is often less about finding one perfect posture and more about rebuilding movement tolerance and physic

One of the most common things Pilates instructors ask clients during a challenging exercise is: "Can you feel that?" The client says yes. Exercise selection alone doesn't determine training stimulus. Load and relative intensity determine how challenging an exercise actually is for the individual. Their legs are burning. They're shaking. They're definitely working. So we assume the exercise is doing its job. But "I can feel it" tells us surprisingly little about whether an exe