New article on "running empty" --exercising before eating

Azdak

If you haven't seen this, it is worth checking out:

http://www.msnbc.msn.com/id/37492881/ns/health-fitness/

A Belgian researcher is promoting some of his work showing that working out on an empty stomach "burns more fat". Before the bodybuilders get too giddy with excitement, I urge everyone to pay attention to the counterarguments described in the remainder of the article.

Here are the main takeaways, IMO:

1. The fuel substrate you burn during exercise has not been shown to be particularly relevant to weight loss. A number of studies have shown that, regardless of how much fat you burn during exercise, the body makes up for it over time and by 24 hours, total fat oxidation is equal, no matter what happened during exercise. People who burned more fat during exercise burned less the rest of the day and vice versa.

2. Workout performance is impaired when you get into a "fat burning" mode. That is basic exercise physiology. Because of the nature of fat oxidation, if you are burning a higher proportion of fat, you cannot work at as high of a percentage of VO2max.

3. These are studies of what would be called an "acute" reaction--a small snippet of "metabolic time" which does not exist by itself. The only way a study like this would be truly relevant is if someone could show a long-term significantly improved rate of fat loss when working out on an empty stomach, controlling all other variables. That is really the only proof of efficacy--not what happens during a solitary 30-60 min slice of time.

Anyhow, now that I have prejudiced the discussion, read on.........:bigsmile:

MercuryBlue

Interesting, thanks!

I know I find that if I don't eat before a workout, I have no energy. Then, I don't work out as hard as I could. So I burn fewer calories than I would had I eaten.


Whether those calories are from fat or not, I don't know. But I work harder and sweat more if I've eaten, so that's why I'll keep doing it!

jillcwhite

I wake up at 5:00am to work out, so I am working out 5 -6 days a week on an empty stomach. I feel like I have as much energy as when I work out later in the day with food in me. I have lost a total of 22 pounds since doing this.

hiddensecant

I tried working out on an empty stomach last year ... it was kinda the "in" thing to do. But this year I I've been making it a point to have something beforehand. And my fitness has improved by huge strides.

I simply have better workouts and it's made me capable of doing more advanced workouts.

Some people swear by running on empty and I don't doubt it ... it just doesn't work for me.

PaulaDygert

Thanks

Laceylala

I just read the article and was getting ready to post it for discussion when I saw Asdak beat me to it. Interesting to say the least.

I work out right after work and have both eaten and not eaten 1/2 hour before I go. I don't know that I've noticed a difference...but I might try not eating for a while right before and see if that brings me any success with burning the fat off my bum faster or not. LOL.

barty

BUMP THANKS

LadyLorax

Interesting...

I practice yoga in the mornings on an empty tummy because of the stretching, but I'm not a big gym rat so I can't really comment on that.

I did read once that going to bed hungry is a good thing because it forces your body to 'clean' out cells for energy and your body is programmed to go after 'bad cells' or dying cells first. When you have a full stomach all the time, your body is too busy dealing with the food to take care of the old or damaged cells as effectively.

Good article. Thanks for sharing.

Azdak

It's also important to remember that the body does enough glycogen stored to perform quite a bit of exercise. Many of our workouts are not long enough or intense enough to use this up, so in many cases this is a moot point to begin with.

I forgot to mention that, as one researcher stated, the primary source of fat used in exercise comes from trigycerides already stored in the muscle.

canstey

I had posted this link on the subject previously in another thread.

http://www.nytimes.com/2006/04/04/health/04real.html

Short version: The fat difference is negligible and are more likely to have a less effective work out due to loss of energy. To me, working out on an empty stomach to burn more fat is like reducing your intensity to stay in "the fat burning zone". A higher percentage yes, but lower totals.

Azdak

I had posted this link on the subject previously in another thread.

http://www.nytimes.com/2006/04/04/health/04real.html

Short version: The fat difference is negligible and are more likely to have a less effective work out due to loss of energy. To me, working out on an empty stomach to burn more fat is like reducing your intensity to stay in "the fat burning zone". A higher percentage yes, but lower totals.

And poorer fitness results. It's kind of like "altitude training". If you go too high, the deterioration in performance offsets any theoretical gains in oxygen-carrying ability. Performance at sea level actually decreases. All you are doing is training your body to perform at high altitude.

canstey

And poorer fitness results. It's kind of like "altitude training". If you go too high, the deterioration in performance offsets any theoretical gains in oxygen-carrying ability. Performance at sea level actually decreases. All you are doing is training your body to perform at high altitude.

Not to change the subject but I thought that thanks to technology (high altitude "tents"), that living high and training low works and is feasible for those with the money and dedication. Not really useful for ordinary people.

Azdak

And poorer fitness results. It's kind of like "altitude training". If you go too high, the deterioration in performance offsets any theoretical gains in oxygen-carrying ability. Performance at sea level actually decreases. All you are doing is training your body to perform at high altitude.

Not to change the subject but I thought that thanks to technology (high altitude "tents"), that living high and training low works and is feasible for those with the money and dedication. Not really useful for ordinary people.

That strategy was developed precisely because of what I mentioned earlier. In the "old" days, athletes would train at high altitudes--and they found that it actually lowered their sea-level performance because they could not train as hard. So they switched to "living high" -which stimulated whatever positive blood changes that might occur at altitude--and "training low" --i.e. training at lower altitudes where they could put out a full effort. Or, they started training at more "medium" altitudes--e.g. 6000-7000 feet--which were theoretically high enough to stimulate some changes but still low enough to allow high performance.

The whole concept of "altitude-based positive changes" is not as straightforward as one might think. In theory, increased number of blood cells would seem like a good thing, but you soon reach a point where the increased "thickness" of the blood offsets the advantages of the increased blood cells (impeded blood flow) and can actually be life-threatening.

questionablemethods

Very interesting.

The running-before-eating that I do is simply out of convenience and motivation. I could grab a quick piece of fruit, I suppose, but if I eat more than that I either have to wait a bit for it to leave my stomach (which I don't have time for in the morning) or I end up getting a terrible side ache (which can definitely ruin a run). It's best for me to just lace up my shoes and head straight out the door before the bed starts to call my name again. Besides, my runs are so short/slow for the time being that I don't think it would make a big difference either way. The idea of getting home for breakfast keeps me going! If my stomach is particularly grumbly, I will have a bit of something before heading out, though.

aippolito1

I also do this more out of convenience. I wake up, get dressed and go for a run. I would have to get up super early to eat before I work out and I simply don't want to do this. So, I go run, come home, shower, get ready, go to work, then eat breakfast when I get there. This morning I had a protein shake after my run 'cause I was starving and then had breakfast and it seems to have worked out well. The main reason for my running (intervals) is to burn more fat than I was before, just walking and doing the elliptical so I was excited to read this article. Sometimes if I'm hungry before I go out, I'll eat 1/2 a banana. I'm usually not out for more than 30 minutes and usually don't cover more than 2 miles so this is safe for me.

DizzieLittleLifter

I prefer to eat before I run in especailly in the AM. Most of my runs are during the week, which means I can't run until DH is home in the eve. My Sat. am run I would run right away without eating. I have found that I can go further, and feel better (ie: stronger) if I eat a light meal an hour before. I will usually eat a whole wheat brittish muffin and almond butter. Thanks for all the info! :happy:

Azdak

Very interesting.

The running-before-eating that I do is simply out of convenience and motivation. I could grab a quick piece of fruit, I suppose, but if I eat more than that I either have to wait a bit for it to leave my stomach (which I don't have time for in the morning) or I end up getting a terrible side ache (which can definitely ruin a run). It's best for me to just lace up my shoes and head straight out the door before the bed starts to call my name again. Besides, my runs are so short/slow for the time being that I don't think it would make a big difference either way. The idea of getting home for breakfast keeps me going! If my stomach is particularly grumbly, I will have a bit of something before heading out, though.

Which gets back to something I have said a number of times: a lot of what comes out as "fitness advice" is derived from, and mostly relevant to, competitive/elite athletes. For many of us, given our level of training and fitness--it makes little or no difference. Often what we perceive as a "benefit" is merely auto-suggestion or a placebo effect. In many cases--and it sounds like your example is one of them--we have plenty of glucose/glycogen to complete the workout, even in a supposedly "fasting" state.

One personal example: I don't bother much with drinking water during a workout if it's less than 30 minutes. When I was able to run, I almost always had a sports drink along for anything 45 min and above. But, I have to admit, I have had as many excellent, "record-setting" 45 min workouts WITHOUT a sports drink or water as I have had WITH them. The same goes for having my music along as well.

The vast majority of exercisers will get more benefit from doing focused workouts and following a planned, consistent routine than all the "eating strategies", sports drinks, supplements, protein, etc COMBINED.

Azdak

I came across a some research a few years ago that was pretty critical of the idea of "fasted" cardio. I don't remember all the details, but the gist of it was that, at the beginning of a workout there is a high need for carbohydrates. It takes several minutes for your fat metabolism to ramp up to full speed. It blood sugar levels were low, the body would scavenge for any glucose/glycogen it could get, with a negative effect on performance. Getting some quick carbs on board provided a readily available source of energy that spared muscle glycogen and provided the fuel needed to carry you through until your energy delivery systems kicked into full gear, so to speak. We are not talking about a full meal or anything--100-150 calories was more than sufficient. And this is for more medium to higher energy workouts of at least 30 minutes. If I am at home and working out first thing in the AM, I would just grab a granola bar, piece of bread, couple of bites of leftover, whatever, 10-15 min before starting the workout and I am fine.

Some days I drive to work first a couple of hours before my shift starts and work out there. It's a 45 min drive, so I just pack a small sandwich (Those Arnolds thin round things, almond butter, preserves--about 275 Calories) and eat is as I am starting to drive. By the time I get to work and hit the machine, I am primed and ready to go.

vineas

We are not talking about a full meal or anything--100-150 calories was more than sufficient. And this is for more medium to higher energy workouts of at least 30 minutes. If I am at home and working out first thing in the AM, I would just grab a granola bar, piece of bread, couple of bites of leftover, whatever, 10-15 min before starting the workout and I am fine.

I found that I needed to do this as well. I work out about 5 AM, right after waking up and didn't have a problem doing it on an empty stomach until I started to get my cardio workouts to about 40-45 mins or more. I started getting massive headaches, dizzy spells, etc. Now, if I'm working out any more than 30 mins, I'll grab a banana or granola bar a few mins before I start, and I'm good to go for about as long as I want to.

hiddensecant

We are not talking about a full meal or anything--100-150 calories was more than sufficient. And this is for more medium to higher energy workouts of at least 30 minutes. If I am at home and working out first thing in the AM, I would just grab a granola bar, piece of bread, couple of bites of leftover, whatever, 10-15 min before starting the workout and I am fine.

I found that I needed to do this as well. I work out about 5 AM, right after waking up and didn't have a problem doing it on an empty stomach until I started to get my cardio workouts to about 40-45 mins or more. I started getting massive headaches, dizzy spells, etc. Now, if I'm working out any more than 30 mins, I'll grab a banana or granola bar a few mins before I start, and I'm good to go for about as long as I want to.

I started drinking a cup of chocolate milk before my workouts. I know it's supposed to be a post-workout drink but it does wonders pre-workout also. I'll have some when I wake up and I'm good to start once I finish checking my email (and forum posts, hehe).

It's especially helpful before really intense cardio like plyometrics; it avoids the nausea you often risk by eating food before a workout like that.

canstey

I usually eat an orange 10-30 minutes before a hard ride.

A note on the water usage. When I first started exercising I needed a lot of water. I bought a second water bottle for my bike because I was going through the first one in an hour. However shortly after that I started needing less and less water during the ride even though it is getting hotter by the day here in Georgia. I guess as I got more fit my muscles were able to hold more water and/or less fat meant easier to bleed out the heat. I still drink about the same total amount it is just now most of it is afterward.