Depends on the exercise. Aerobic exercise, like walking, will bring your blood sugars down. However if you are doing anaerobic exercise, running, heavy weights, so pushing yourself your body will be demanding more energy, your liver will oblige, dumping more glucose into your bloodstream. However your cells won't take this up quickly enough due to insulin resistance, so yes your blood sugars will then rise. If I spend an hour in the gym, and work up a sweat, run my heart at about 95% capacity my blood sugars will rise significantly. If I take a 3 mile stroll along the beach, they drop