cardio question

[EMC]

what do you guys think about cardio on empty stomach vs cardio after eating?

what do you guys think about cardio post workout and first thing in the morning? i know alot of people do cardio in morning on empty stomach!

[Phedder]

If fat loss is your only goal from cardio, then fasted morning cardio is a great way to achieve that goal. There is a greater amount of FFAs present in your blood after waking up, and doing low intensity cardio uses primarily FFAs as an energy source if they're available, hence it being a great method for fat loss. Personally I prefer to get training adaptations from my cardio, and enjoy HIIT much more than long slow distance running, which just bores me. If you want to get fitter and faster, fasted morning cardio is definitely not the right choice.

Here's a link to a great discussion of the topic, a bit of a long read but if you're interested it's definitely informative. http://www.tmuscle.com/free_online_article/sports_body_training_performance_interviews/the_fasted_cardio_roundtable

[EMC]

thanks. it was a great read, but very anecdotal.

[Elite121]

Man so many varying opinions on Cardio training on an empty stomach..clearly more research is needed, check this article out by Alan Aragon:

FALSE HOPES FOR FASTED CARDIO

The bandwagon is lead by blind horses

Many trainees pigeonhole weight training as an activity exclusively for building muscle, and cardio exclusively for burning fat. On the contrary, weight training can yield very similar results to cardio of similar intensity when 24-hr energy expenditure and macronutrient oxidation is measured [14]. The obvious advantage of weight training is the higher potential for lean mass and strength gains. In the bodybuilding context, cardio should be viewed as merely an adjunctive training mode to further energy expenditure and cross-complement the adaptations specific to weight training. As far as cardio being absolutely necessary for cardiovascular health, well, that depends upon the overall volume and magnitude of your weight training - another topic for another time.

Chaos theory strikes again

On the surface, it seems logical to separate carbs from cardio if you want a maximal degree of fat oxidation to occur during training. But, there***8217;s the underlying mistake - focusing on stored fuel usage during training instead of focusing on optimally partitioning exogenous fuel for maximal lipolytic effect around the clock. Put another way, it***8217;s a better objective to coincide your carb intake with your day***8217;s thermic peaks, where insulin sensitivity & lean tissue reception to carbs is highest. For some reason, this logic is not easily accepted, nor understood. As we know, human physiology doesn***8217;t always cooperate with logic or popular opinion, so let***8217;s scrutinize the science behind the claims.

LET THE RESEARCH SPEAK

Carbohydrate ingestion during low-intensity exercise reduces fat oxidation

As far as 3 decades back, Ahlborg***8217;s team observed that carb ingestion during low-intensity exercise (25-45% VO2 max) reduced fat oxidation compared to fasted levels [15]. More recently, De Glisezinski***8217;s team observed similar results in trained men at 50% VO2 max [16]. Efforts to determine the mechanism behind this phenomenon have been made. Coyle***8217;s team observed that at 50% VO2 max, carbohydrate availability can directly regulate fat oxidation by coordinating hyperinsulinemia to inhibit long-chain fatty acid transport into mitochondria [17].

Carbohydrate***8217;s effect on fat oxidation during moderate-intensity exercise depends on conditioning level

Civitarese***8217;s team found glucose ingestion during exercise to blunt lipolysis via decreasing the gene expression involved in fat oxidation in untrained men [18]. Wallis***8217; team saw suppressed fat oxidation in moderately trained men & women when glucose was ingested during exercise [19].

In contrast to the above trials on beginning and intermediate trainees, Coyle***8217;s team repeatedly showed that carb ingestion during moderate-intensity (65-75% VO2 max) does not reduce fat oxidation during the first 120 min of exercise in trained men [20,21]. Interestingly, the intensity margin proximal to where fat oxidation is highest was unaffected by carb ingestion, and remained so for the first 2 hours of exercise.

Horowitz***8217; team examined the effect of a during-training solution of high-glycemic carbs on moderately trained men undergoing either low intensity exercise (25% VO2 max) or high-moderate intensity (68% VO2 max) [22]. Similar results to Coyle***8217;s work were seen. Subjects completed a 2-hr cycling bout, and ingested the carb solution at 30, 60, and 90 minutes in. In the low-intensity treatment, fat oxidation was not reduced below fasted-state control group***8217;s levels until 80-90 min of exercise. In the 68% group, no difference in fat oxidation was seen whether subjects were fasted or fed throughout the trial.

Further supporting the evidence in favor of fed cardio in trained men, Febbraio***8217;s team investigated the effects of carb ingestion pre & during training in easily one of the best-designed trials on this topic [23]. Subjects exercised for 2 hrs at an intensity level of 63% VO2 max, which is now known as the point of maximal fat oxidation during exercise [1]. Result? Pre & during-training carbs increased performance - and there was no difference in total fat oxidation between the fasted and fed subjects. Despite the elevated insulin levels in the carb-fueled groups, there was no difference in fat availability or fat utilization.

Summing up the research findings

***8226; At low intensities (25-50% VO2 max), carbs during exercise reduce fat oxidation compared to fasted trainees.

***8226; At moderate intensities (63-68% VO2 max) carbs during exercise may reduce fat oxidation in untrained subjects, but do not reduce fat oxidation in trained subjects for at least the first 80-120 minutes of exercise.

***8226; Carbohydrate during exercise spares liver glycogen, which is among the most critical factors for anticatabolism during hypocaloric & other conditions of metabolic stress. This protective hepatic effect is absent in fasted cardio.

***8226; At the established intensity level of peak fat oxidation (~63% VO2 max), carbohydrate increases performance without any suppression of fat oxidation in trained subjects.

__________________

[vinnie700]

ive done fasted cardio before and lost fat really quickly. i highly recommend it. as you know everyone's different, but i personally responded well to it.

this was my routine,

wake up,

take 150mg caffine on empty stomach.

jog to running grounds (5-8min warm up)

stretch

20 mins high intensity interval training (100m sprints)

5-8 minute rest

25 mins circuit jogging

wait 40 mins or so before eating

you probably know the theory - burn up atp, burn glycogen, no food in stomach so goes straight to fat stores, fat stores are released, burn fat stores. caffine just gives you an edge and supposedly helps fat metabolism/transport.

thats pretty much a typical routine, but it takes less than an hour and its the most effective thing for me.

[Phedder]

i

you probably know the theory - burn up atp, burn glycogen, no food in stomach so goes straight to fat stores, fat stores are released, burn fat stores. caffine just gives you an edge and supposedly helps fat metabolism/transport.

Part of the reasoning behind fasted cardio after waking up is that the FFAs are already in your blood stream ready to be used as an energy source. When we sleep our primary source of fuel is FFAs because there is a very low energy demand, upon waking these FFAs are still in the blood stream and easy to burn off. Starting exercise doesn't necessarily trigger a release of FFAs into the blood stream, they're already there. From what I know I'd think starting exercise would increase the release of glycogen stores in muscle due to the increased energy demand, but because the fats are already there they'll get burned off also. I can't imagine it'd take very long before the FFAs that were left in the blood from sleep to be burnt off and the body then utilizing glycogen stores as the primary energy source. During high intensity exercise, fat doesn't release enough energy per unit of oxygen to meet the demands, so carbs are used because they release more energy per unit of oxygen. Keep the intensity low to best burn off the FFAs after waking if fat loss is the main goal.

[EMC]

Elite121 where is this referenced from?

[Chillicat]

There was something in the news recently about a study that showed good results for fasted cardio - though only for men. Women for whatever reason were better off not doing it fasted.

Sorry, but can't remember any more than that, but it was very recent. Was there a post in here somewhere about it? Maybe someone else can remember?

[Pseudonym]

Good discussion, guys.

When we sleep our primary source of fuel is FFAs because there is a very low energy demand

So are you saying the effect of doing cardio on waking has more to do with the body switching fuel sources while sleeping, rather than the "empty stomach" theory?

[Donny]

i dont like to train and run early mornings on an empty stomach. You can get fat burning too if you do cardio direct after weight training.

[Phedder]

Good discussion, guys.

When we sleep our primary source of fuel is FFAs because there is a very low energy demand

So are you saying the effect of doing cardio on waking has more to do with the body switching fuel sources while sleeping, rather than the "empty stomach" theory?

I can't give a definitive answer, but that makes the most sense to me. The FFAs are already in your system in abundance, so might as well burn them off. I'm not actually sure how the body responds in exercise 4-5 hours since your last meal, but I'd assume it'd be more inclined to use glycogen stores in the muscle than to go through the process of mobilizing the fats for energy when it can get energy more efficiently through carbs. I'm just a student, by no means a master so maybe someone with more knowledge on the subject could offer some better insight.

Despite what studies show and the scientists tell us about the most effective ways to lose fat or increase our fitness etc, I'd still say the most important thing about cardio and exercise in general is to do it when it suits you and via a method that you enjoy. If it's inconvenient and you don't enjoy it then you're less likely to continue doing it. As long as you get out there and get moving you're going to see results, perhaps not to the same extent or as quickly as if you follow some recommendations, but unless you are a serious athlete who needs to get specific results fast, finding ways to enjoy a healthy lifestyle is the most important thing.

I'm getting pretty good at rambling on haha, gotta keep an eye on that.

[vinnie700]

yeah thats what i was saying, atp -> glycogen -> fat. i always thought when the glycogen levels dropped, fat would be metabolised as a fuel source. and having an empty stomach made that a quicker process. im not sure the exact theory, but im pretty sure thats the jist of it.

i didnt know about the fat being released during sleep though and the idea of fasted cardio being to burn off that straight away.

so im not too sure now, ill have to ask someone at uni or something now haha. but i do know that it seems to work for me, so whatever!

[Phedder]

atp -> glycogen -> fat.

Just to clarify, ATP is the energy molecule. The body can't store much of it at all though, so it's constantly being used and re-synthesized, I've heard that the human body produces its own weight in ATP each day. Glycogen and fat get metabolized into ATP, which the body uses to power everything. You just get more ATP per unit of oxygen from glycogen than fat, which is why glycogen is used when energy demand is high. The majority of the time, energy comes from a mix of carbs, fats, and proteins, it's just the contribution from each that changes with what's available and the energy demand.

If it works for you, keep it up :nod:

[vinnie700]

atp -> glycogen -> fat.

Just to clarify, ATP is the energy molecule. The body can't store much of it at all though, so it's constantly being used and re-synthesized, I've heard that the human body produces its own weight in ATP each day. Glycogen and fat get metabolized into ATP, which the body uses to power everything. You just get more ATP per unit of oxygen from glycogen than fat, which is why glycogen is used when energy demand is high. The majority of the time, energy comes from a mix of carbs, fats, and proteins, it's just the contribution from each that changes with what's available and the energy demand.

If it works for you, keep it up :nod:

interesting, but hows it possible for the body to produce its own weight in atp a day? so. if i weigh 80kgs, and my body produces 80kgs of atp a day, and i didnt eat anything that day, my whole body would turn into atp? 80kgs of atp has to come from somewhere lol. i dont think thats right. i know that like an 80kg body could potentially consist of like 5 or so kgs of glycogen. but i cant see how it can make 80kgs of atp. or was 'produce' the wrong word? does it just like re use itself or something up to that weight??

i thought atp was more of the primary instant, sudden action muscle fuel, which is stored in the muscles and quickly diminished, then the (almost instant) change over to secondary muscle fuel glycogen occurs, then the carbs/protien/fat metabolism for fuel occurs (replenishing atp/glycogen stores) as glycogen stores deplete. i thought the body feeds directly off atp AND glycogen, and not that glycogen had to turn into atp/"energy molecule" before it was usable for energy. i know that carbs/what you eat turns to glucose/glycogen and its used, but i didnt know it then has to turn into atp before it can be used. i thought they were 2 separate sources of energy, both as the "final product" ready to be used.

oh well you learn something new every day

lol its like you need a science degree to fully understand this stuff.

[Ronin]

The body's energy comes from breaking ATP (adenosine tri-phoshphate) down into ADP (adenosine di-phosphate) and a single phospate ion, which releases a large amount of energy. The ADP is then re-phosphorylated back into ATP to be re-used. The trick is in which energy system the body uses to re-create the ATP.

The fastest and most powerful is your creatine system, which delivers instant energy due to intramuscular stores of phospho-creatine surrendering a phosphate ion to ADP -->ATP. This system will only power you for the first few seconds and then it runs out of steam.

Next up is your anaerobic glycolitic system, which breaks down blood glucose and stored glycogen to provide for the rephosphorylation of ADP. The end result if you're working anaerobically is a buildup of lactic acid, which will affect your muscle's continued performance, and you stop. It's still quite a powerful source of energy, and provides it fairly quickly, but has a pretty limied capacity due to the effects of the lactic acid, up to about a couple of minutes.

Then you have your aerobic system, which provides a hell of a lot of ATP, but takes a lot longer to produce it. Unlike the creatine system (which uses creatine exclusively) and the anaerobic (which uses glucose and glycogen) the aerobic system will draw on CHO, fats and proteins to generate ATP, depending on what's available and how quickly the body demands energy.

Then, once the ATP has been produced, it'll be broken down again to provide energy, and the whole process starts again. This goes on continuously, the ATP isn't just used when you decide to pick up a barbell, it powers everything from breathing, blinking, scratching your balls, right up to your workout. So yes your body is producing a crapload of ATP, whether it is it's own bodyweight, I don't know (not disagreeing, I've just never heard that particular factoid before), and no, if you lump out for the day, your whole body won't turn into ATP. The body produces what it needs. One figure I have heard is that each cell produces and burns 10 million molecules of ATP each second at rest.

So you're kind of on the right track as far as the order goes, but the only thing that's "turned into" ATP is ADP. Everything else is geared towards making that happen, regardless of which fuel source you're using, and how you're exercising. How you train then will dictate at what point the body starts to use fats and even proteins as its preferred energy source.

That's a very simplified version of events, but hopefully it's helped a little. I know it can get a little confusing at times, it took me a while to get my head around it at first.

[vinnie700]

wow thanks Ronin. that was very informative. and now i see how the body can 'produce' so much weight of atp without any input/loss. as its broken down into adp then being burnt and is re-created as a byproduct of burning adp (if i read that properly).

well at least i wasnt COMPLETELY wrong with some of the other stuff. haha.

lol we've totally taken over this thread, but that answered a lot of questions for all probably anyway.

cheers!

[Im Hungry]

If you eat energy yielding carbs at night then they will be stored as glycogen and used to fuel your cardio the next morning. The morning cardio will work if you keep your energy carb intake low from mid afternoon the previous day (excluding post exercise recovery carbs and presuming sedentary job). I recommend my clients do 15- 20 minutes intense (hills/ steps or machine) to deplete any glycogen (made via gluconeogensesis) and the 40 mins at up to 2.2 x resting heart rate for target fat burning heart rate. Do a minimum 45 mins and ideally 60 mins.

The advantage of doing cardio after weights is that your muscle glycogen stores will be sufficiently depleted that when you do the cardio the body taps into fat stores fairly quickly (presuming heart rate is 2.2 x resting) as long as you didn't consume too many carbs pre-workout.

if you want to compete at less than 4% body fat you'll likely need to do both in at some stage during your 12 week prep

[ani_m0L]

...

if you want to compete at less than 4% body fat you'll likely need to do both in at some stage during your 12 week prep

I think that about summed it up!

Are you looking at strippin some fat? :pfft:

[JOSEF RAKICH]

what do you guys think about cardio on empty stomach vs cardio after eating?

what do you guys think about cardio post workout and first thing in the morning? i know alot of people do cardio in morning on empty stomach!

Cardio on an empty stomach is stupid.

Cardio first thing in the morning and post-workout are the worst times to perform cardio (funny though post-workout is when i perform my cardio lol, but im smart about it)

Morning cardio is probally the best time to perform cardio for fat loss due to you are in a fasted state, but fat loss is never number 1 goal when dieting, its preserving muscle mass. morning cardio is good for fat people wanting to lose weight, but not a bodybuilder.

So you eat every X amount of hours or so to keep anabolic, yeh you go 8 or so hours without any food get your body into a fasted state then perform work on top of this!? I dont see the logic in that. Performing morning cardio you will more likely break down muscle for fuel also, upon waking is one of the most catabolic times of the day.

If you want to do morning cardio have a meal first, a rule you should follow is dont do cardio to burn fat, do cardio to burn calories. Fat loss occurs from calories out VS calories in, if you are in a calorie deflect you will lose fat dont worry about burning fat during cardio. Open your eyes and look at the bigger picture.

[Phedder]

Firstly, you do realise that anabolism and catabolism are occuring constantly, at the same time, within your body, right? The whole 'staying anabolic' and 'not becoming catabolic' talk is bullshit

Training in a fasted state can actually have many desireable outcomes, no need to eat before going for a morning run. If you want to do cardio before eating, go for it. If you want to have a meal first, go for it. Do whatever the hell you want as long as you actually do the cardio.

http://www.leangains.com/2010/09/fasted ... ivity.html

[tonyb]

Ive been training in a fasted state for the last three weeks now and have had excellent results. My last meal is 9pm, then I wont eat until 1pm the next day. I train from 12pm to 1pm fasted (although I have about 10g of BCAA before training). Then I have a meal at 1pm, another at 5pm and the last meal at 9pm.

Rinse & Repeat

[JOSEF RAKICH]

Firstly, you do realise that anabolism and catabolism are occuring constantly, at the same time, within your body, right? The whole 'staying anabolic' and 'not becoming catabolic' talk is bullshit

Training in a fasted state can actually have many desireable outcomes, no need to eat before going for a morning run. If you want to do cardio before eating, go for it. If you want to have a meal first, go for it. Do whatever the hell you want as long as you actually do the cardio.

http://www.leangains.com/2010/09/fasted ... ivity.html

One should not perform cardio in a fasted state.

The logic being that if one is in a fasted state, their glycogen levels will be low and will force their body to burn fat. Unfortunately, no.

While performing cardio in a fasted state may indeed increase the amount of calories that are burned from fat stores, it will also increase amino acid oxidation. Cardiovascular exercise while in a fasted state is a great way to increase cortisol release. Cortisol will liberate amino acids to produce glucose (glucose cannot be synthesized from fats) and can lead to muscle loss.

I find it ironic that many people take such great care to time their meals so that they do not go for more than 2-3 hours without eating in order to prevent muscle loss. However, they purposefully induce this state and then perform work on top of this..

Research has shown that the type of substrate used during cardiovascular work makes little overall difference on fat loss. This is most likely due to the fact if one relies mostly upon fat stores during cardio the body will burn predominantly glucose at other times of the day. Likewise, if one mainly utilizes glucose for energy during cardio the body will customarily rely on fat at other times of the day in order to spare muscle glycogen.

When dieting the most important thing is preserving muscle, the 2nd thing is fat loss.

[Phedder]

Did you even read that link? Or are you just so set in your ways you won't consider anything other else?

Cardiovascular exercise while in a fasted state is a great way to increase cortisol release. Cortisol will liberate amino acids to produce glucose (glucose cannot be synthesized from fats) and can lead to muscle loss.

ANY exercise will increase cortisol release, fasted or not. Gluocse CAN be synthesized from fats, glycerol.

The logic being that if one is in a fasted state, their glycogen levels will be low and will force their body to burn fat. Unfortunately, no.

Actually the logic usually is that the body has been using mostly fats for energy prior to exercise and hence there are plenty of FFAs in the blood already, and the exercise is used as a way to utilize those available FFAs. Glycogen levels will be lower than if you had just fed, but they won't be low. We store a heap of glycogen in both our muscles and our liver, you'd have to be doing hours of HIIT to drop glycogen levels low enough to require gluconeogensis to provide the energy.

I find it ironic that many people take such great care to time their meals so that they do not go for more than 2-3 hours without eating in order to prevent muscle loss

I just find it plain laughable. OH NOES I HAS NOT EATEN IN 4 HOURS, MY MUSCLES ARE WASTING AWAY!

[JOSEF RAKICH]

Firstly, you do realise that anabolism and catabolism are occuring constantly, at the same time, within your body, right? The whole 'staying anabolic' and 'not becoming catabolic' talk is bullshit

Training in a fasted state can actually have many desireable outcomes, no need to eat before going for a morning run. If you want to do cardio before eating, go for it. If you want to have a meal first, go for it. Do whatever the hell you want as long as you actually do the cardio.

http://www.leangains.com/2010/09/fasted ... ivity.html

Yes, but they are not constant. There are times when one is more anabolic and there are times when one is more catabolic during the day depending upon certin factors.

They way i look at it is you should just treat cardio like a weights session.

[Phedder]

They way i look at it is you should just treat cardio like a weights session.

And how do you think they should be treated?