Will exercising before breakfast burn more fat?

LeAjaSimone

I was always told that it does not matter what time of day to exercise. The results are still the same as long as you are eating properly. The best thing is to pick a time of day that is best for you and try to stick with it. For me, I like to eat a meal first because my mornings start off pretty busy, getting my daughter ready for school, and fixing breakfast (if I have time) for my husband and kids. Once I smell the food, my stomach is doing cartwheels...lol. So, I workout after my first meal or morning snack. If I wait till the evening then I may miss that day because I am exhausted from my daily activities. However, and I think you may already know this, but to burn fat, any time of the day, the best thing is to stay within your fat burning zone for at least 20 mins. Its hard for me to do that while doing cardio, so I do LesMills Body Pump, a weight lifting class. Best of luck!!

krissielynn87

At BCT for the Army, we always PT'd before breakfast.
I dropped 30lbs when I was in basic.
Unfortunately, I've put it back on.

PT was always before breakfast, but one of my drill sergeants made sure everyone in my platoon had access to a king sized Snickers bar before our final test. I don't doubt at all that having bit of fuel in me helped improve my performance.

I rarely have the energy to workout before I eat. I'll eat about 30-60 minutes before my workouts.

Jealous! We weren't allowed any "fat cakes" or anything. At least not until I got medically discharged. But such is life

toddis

I thought previous studies showed a small benefit of ~5%.
20% is crazy.

Timshel_

It's been pretty well established that cardio in a fasted state does burn more fat as fuel but what I've read previously has suggested that the difference is modest at best.

This. Latest reading I have done suggests that calorie burn is calorie burn no matter when you do it. Same as people who say to "fast" before bed by eating dinner earlier, so the body burns more calories while sleep. BMR is BMR and your body will burn almost the same weather sleeping or in the day. As mentioned, anything in between is modest at best.

Azdak

Here is a link to the entire article:

http://dx.doi.org/10.1017/S0007114512005582

look on the page and there is a link to a PDF copy. Hopefully it will work for you.

I just scanned it because I'm short on time. I was looking for the raw data on fat oxidation during exercise, but missed it. It was interesting that it looked like the breakfast eaters burned about 15% more calories during exercise than the fasters, but that may have been explained away somewhere else.

I also was curious to see no mention in the references to the review article publshed in 2009 by Melanson et al, that strongly suggested that exercise does not improve 24 hr fat oxidation--and whatever differences in substrate utilization that occur during the exercise bout are evened out over time so that, at the end of the day, there is no difference in total body fat oxidation. Having read that study, I don't accept any conclusions that aren't reached after spending at least 24 hours in a metabolic chamber.

And even if it were true and the difference was real, keep in mind that a 20% difference in a one hour workout likely translates into about 1/2 an ounce of fat. Hardly worth bothering about. Especially given the higher potential for an adverse workout effect when exercising in fasted state.

Keep in mind as well that when people talk about "eating before a workout", we are not talking about a Denny's Grand Slam breakfast. The preexercise feeding is more like a 100-200 calorie, easily digestible snack.