An intense workout is the most efficient way to fight fat, according to new research. Experts have long known that regular exercise helps lower the spike in triglycerides (fat in your blood) that happens after you eat. But a study by the University of Texas suggests that interval training may lower triglyceride levels more than working out longer but not as hard. "The different intensities might modify the way fat and carbohydrates are burned or stored after exercise," says lead researcher Justin Trombold. "By exercising a bit harder, you could save time and get similar, if not better, health benefits."