Granted, we have known this for a while but this may be the study that shuts the door on the myth for good. Eleven men and women did more than 1,000 repetitions of leg press with their non-dominant leg, three times a week, for 12 weeks, and made no dietary changes. At the end of the training program, the participants boasted a 10% drop in fat mass—in their arms. Participants in the Journal of Strength and Conditioning Research study also whittled their core area, losing an average of 7% of fat mass in that spot. Remember: they did 1,000 repetitions with only ONE leg. “For fat reduction in any region, we need to alter the hormonal environment,” says study author Rodrigo Ramírez-Campillo, MSc, an associate researcher in the department of physical activity sciences at Los Lagos University in Chile—which is exactly what the training protocol achieved. By expending major energy a chain of body-wide hormonal responses—lowered insulin levels, increased adrenaline levels, and a bump in the release of fatty acids from storage—was started.  This small study’s results are backed by previous research; which also helps explain the fat loss the participants experienced. “Previous studies show that the trunk is the first region to exhibit a significant reduction in fat,” Ramírez-Campillo says. “The higher the fat mass of an area of the body, the higher the probability that the subject will reduce the fat mass in that specific region.” And while this may not be exciting news for those who like crunching until the cows come home, know this: This whole-body benefit of unilateral training can come in handy if you get injured. By continuing to exercise with your non-injured limbs you can still “achieve significant fat reduction in the trunk, and reduce the possibility of cardio-metabolic diseases,” Ramírez-Campillo says. More from Prevention: Strength Training Exercises For Every Part Of Your Body