Weight Training Can Help Keep the Pounds Off, New Study Confirms. A recent study found that those who incorporate some type of weight training into their exercise routines ... . ... were between 20 and 30 percent less likely to develop obesity. The study was published in June in the medical journal 'PLOS Medicine.'. It cross-checked data of more than 12,000 mostly middle-aged participants of a well-known fitness survey conducted from 1987 through 2005. The findings of the study indicate that those who trained with weights between a total of one to two hours a week in addition to their regular cardio routines ... ... were much less likely to become obese over the course of several years as they aged. Researchers say that more the half of all Americans will be obese by 2030. Once in the obese range, the weight is likely to either stay or return even for those who have lost weight. The study suggests that weight training can help a person prevent obesity altogether