When you sit for prolonged periods, your body is forced into compromised positions, which leads to compromised function. And when you sit all day, you simply don't move enough. Working out will certainly make you healthier overall, but it's not a time machine that can undo the sedentary choices that you make over the rest of the day. The deterioration process may be slow, it is methodical, and if left unchecked, it eventually will have a huge impact on all aspects of your life, including your resiliency and performance.There is a difference between exercise and non-exercise activity. Exercise typically means activities like running or weight training. Despite the intensity of the workout, you usually do it for a relatively short period. Non-exercise activity is what you do when you're not exercising at high intensity - things like standing, walking, gardening, cooking and even fidgeting.