While some enjoy sleeping in, others prefer to be early risers (prefer or have no choice) & tend to workout in first thing in the morning…
When working out in the morning, our body is at a fasted state. Some research has shown that fasted cardio & fasted workouts lead to increased fat burn. Others believe that exercise intensity is reduced at a fasted state resulting in a lower EPOC* effect following the workout. Which is right?
Possible Plus Side of Fasted Cardio
When you wake up first thing in the morning, your body has reduced levels of glycogen (carbohydrate) levels due to the fasted state your body has been in for the past 8 hours (hopefully) while sleeping. The theory is that when you work out early in the morning on an empty stomach, a shift in energy utilization away from carbohydrates occurs, therefore allowing greater mobilization of stored fat for fuel. Simply put, you’re burning more fat than carbohydrates since glycogen levels are so low. This theory doesn’t necessarily apply to only morning cardio, it could be to exercise in any fasted state although typically first thing in the morning would be when glycogen levels are most depleted, resulting in greater fat utilization.
Possible Arguments Against Fasted Cardio
In terms of weight loss, it all goes back to calories in vs. calories expended though. Some theorize that whether you’re burning glycogen or burning fat, you’re still burning calories. In order for weightloss to occur you must burn more calories than you consume.
In addition, as I mentioned before, some argue that intensity of workout decreases while at a fasted state. With a decrease in exercise intensity, comes a decrease in EPOC*. Personally, I feel that this is very subjective. I feel that most of my best and intense workouts are before 9am.
Since nothing is set in stone & research goes both ways on this topic, I suggest to do what works for you. If you have a high stress job or are under a ton of stress in general, maybe that hour of extra sleep is going to be more beneficial for you in the morning then you can make time for a workout mid-day or evening. If you know you don’t have a full hour for a workout in the afternoon or evening, divide up your workouts & do a 30 minute Fartlek run in the morning (just an example) then lift in the evening. Regardless of what you do, just make sure you get your workouts in & make sure you’re making them worth your time. If you’re able to read a book while biking or running, chances are you need to kick it up a notch…if you need tips, e-mail me & I’ll be happy to send them your way! : )
*EPOC= Excess Post Oxygen Consumption; Following an intense workout, the body demands more oxygen in attempts to return back to resting levels. This results in increased metabolism following a workout. You can read more about this in