Fructose
Another monosaccharide, you'll find fructose in fruit, fruit juice, honey and vegetables. It differs from glucose in that the liver breaks it down before it moves through your blood and then to your muscles. Another drawback: Free radicals and triglycerides (a type of fat), form as by-products as your liver processes fructose. So getting an excess amount can directly contribute to weight gain. To avoid this, try to stick to two cups of fruit a day, limit juice and don't overdo it on the honey toppings. A small banana or handful of raisins can go a long way pre-cardio sesh.Sucrose
Also known as table sugar, this dissacharide is derived from plants like sugarcane (labels may read dried cane syrup). It's also what you'll get from brownies or cookies (though we're not condoning munching on those before an intense gym visit).
Sucrose breaks down into equal parts glucose and fructose in the small intestine, where these simple sugars are eventually absorbed through the intestinal wall. It then gets into the bloodstream, where a protein takes the glucose to muscle cells to use for energy or store for later use