One of the key health benefits of exercise is that it helps normalize your glucose, insulin, and leptin levels by optimizing insulin/leptin receptor sensitivity. Exercise-improved insulin/leptin receptor sensitivity is perhaps the most important factor for optimizing your overall health and preventing chronic disease.
Exercise also encourages your brain to work at optimum capacity by causing your nerve cells to multiply, strengthening their interconnections, and protecting them from damage. Unexpected side effects of exercise include improved changes in gene expression, clearer skin, and improved mood and sleep
Research shows that the “secret” to increased productivity and happiness on any given day is a long-term investment in regular exercise, and a little each day appears to go further than a lot once or twice a week.