New research looks at what happens with everyday exercise on an empty stomach.

Should you roll out of bed and out the door for a brisk morning walk, or fuel up and hit the gym hard?

Your friends and blogs have plenty of advice, and nutrition pros qualify their recommendations for the best approach to meal timing and activity. A new UK study (finally) looks more closely at what happens when average people exercise moderately after an overnight fast—that is, when they wake up in the morning.

University of Bath researchers found that study participants who walked on a treadmill first thing burned more fat. Those who first ate a controlled breakfast burned slightly more calories. The scientists were careful to conclude that their findings don’t point to a universal recommendation for accelerating weight loss. But they found that the group who exercised after fasting showed greater activity among genes responsible for the production of proteins that can improve blood sugar regulation and insulin levels throughout the body. That’s definitely a plus for your metabolic health.


Photo credit: tommaso79, ThinkStock