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Fasted Workouts: The New Thinking and Latest Science

The pros and cons of skipping breakfast before a tough workout.

Morning workouts are awesome: Aside from the convenience of getting it done and being on with your day, first-thing-in-the-AM sessions have been shown to boost energy all day long. But one of the much-debated and heated arguments in the fitness and nutrition world revolves around whether or not you should eat before those early sessions. So, we spoke to the experts, combed throught the latest research, and compiled the pros and cons of fasted workouts. Click to page three for the bottom line!

The Pros of fasted workouts:
You may burn more fat
There’s some evidence that fasted cardio workouts (i.e., not eating before you hit the gym) can burn more fat. "Glycogen is the stored carbohydrate that your body uses as its preferred fuel source during exercise," explains Men's Fitness Training Director Sean Hyson. "The fasted cardio crowd says that because glycogen is somewhat depleted in the morning after the night's fast, your body will burn a greater percentage of fat during training as its next resort," he explains. "Most of us have some sort of meal within two hours before we go to bed and we rarely sleep for more than 8 hours, so if you get up and start training 10 or so hours after your last meal, your glycogen will be low, but it won't be gone, so it could be argued that you'll have just enough glycogen left to train hard, but low enough levels that you'll burn more fat than normal to compensate for it."

It prevents indigestion
Eating breakfast right before you hit it hard at the gym is, in most cases, indigestion waiting to happen. “Too large a meal within a two-hour time frame of activity can slow you down and draw blood from the body to aid with digestion,” says Sam Accardi, R.D., a performance dietitian at Philadelphia-based AFC Fitness and The Charge Group

You can train yourself to feel less hungry
If you're the type that wakes up ravenous, have faith that it is possible to get through a workout without eating something first (assuming that you ate dinner the night before.) "You can ween yourself off breakfast if you want to—it just takes time," says Hyson. "Start drinking water first thing in the morning and you’ll keep satiated." And bring gels or a banana along with you if you're doing a long endurance run (60+ minutes) in case you feel like your fast is impacting your performance too much. 

Click to the next page for the cons >>>



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