Have to get back at this one apparently. This is one of those myths that just won’t die. I see it all the time at the studio and am asked frequently if it is a good idea or not.
Should you workout on an empty stomach first thing in the morning?
There are two reasons people do this. The first is that they have fallen prey to the fat burning zone ideology (which incidentally doesn’t seem to have panned out with leaner waistlines on the beach) and are attempting to maximize their fat burning after waking from a fast overnight. The belief is that because you have been fasting (sleeping) you are primed to work in that magical fat burning zone (around 60% max effort) and obliterate fat cells faster than at any other time of day.
Group two are people who workout in the morning but has a hard time eating either in the morning, or before a workout. This makes things doubly difficult for some. If you are in this category the thought of getting up and eating something makes you feel somewhat queasy. For others in this group eating within a half hour to hour of working out increases the chance they will be making a quick trip to the bathroom after their first few sets.
What is the truth? What are the facts? Should you eat in the morning and then workout or should you workout before partaking in the days most important feeding time?
Here is the simple answer: never workout without putting fuel in your body.
We eat for one reason: to provide our body with the resources necessary to move, function, build, and grow. If you are not well fed then the basic processes in your body will suffer. This is just basic biology 101.
The idea that you will burn extra fat if you exercise on an empty stomach is bunk. If you workout at 60% your max effort, let’s say you burn 500 calories in an hour and 60% are from fat. That means 300 calories are from your jiggly arms and bubbly belly, maybe some from the little bit of swishing extra thigh meat.
Now, let’s say you workout at 85% for 45 minutes doing HIT intervals. This same person could conceivably annihilate 800 calories. But at this intensity the percentage of fuel burned from fat decreases s, your body turns to glycogen (think of this as carbs for now) for energy. Our example might burn 30% of calories from pesky fat globules, which is about 250 calories from fat. This is about the same as the 60% starvation case above in three quarters of the time.
The HIT person also enjoys the benefits of larger improvements to the cardiovascular system, increased strength and power, improved hormone response, and will likely keep exercising longer because they aren’t bored to tears staring at the little red blinking numbers on the elliptical machine.
The theory, therefore, is disproved. Working out on an empty stomach will not decrease your fat ass better than a good well fuelled exercise program.
It would be impossible to exercise at 85% your max effort for over a half hour without providing your body some fuel because at that level of intensity your body requires glycogen (as above: think carbs) to fuel activity.
You will not maximize your workout effort if you are not eating in the morning. In fact, I think it is just stupid and have been known to send clients home if they consistently show up without eating (yes, that is a warning to all you members reading this!)
Ideally, eat some good complex carbs (oatmeal, rye toast, whole wheat wraps etc) 30-45 minutes prior to your workout. If you workout at 6am and simply refuse to get up at 4am then this is the one time we recommend simple carbs pre-workout. Fruit 25-30 minutes prior to the workout will do the trick.
For those of you who simply cannot get food into you in the morning, this is the only time I will tell you to enjoy some juice. No preservative, not from concentrate, no sugar added fruit juice, 15-20 minutes before your workout will get that glycogen into your system just in time to get a real workout.
If none of this works for you, keep your complaining ass in bed and workout later in the day!