I suggest meter reading befre and after. Moderate, even light exercise is best, so you don't over do or get frustrated by the effort and slow results. Any lowering of blood sugar level is good for me since mine tends to rise and peak in the early evening. When I feel the most tired is when my glucose is highest. After 30 minutes on the treadmill at 4 mph I find normally an 80 point dcrease. Thats good for me, trying to stay under 180 but 160 is recommended.