Fasted cardio with more than a few % points to lose.
- 01-25-2011, 12:57 PM
Fasted cardio with more than a few % points to lose.
Ive heard fasted cardio is great for when a person needs to lose those last few %points of fat. Is it bad at other times. Will it burn too much muscle or something?
By the way, I realise that diet is the most important factor in loseing weight, so before nyone says that, I beat you to it
- 01-25-2011, 01:39 PM
The most important factor for losing weight is a caloric deficit-either by diet restriction, exercise, or a combination of both. Fasted cardiorespiratory exercise has no benefit over unfasted. You will fatigue much faster and possibly become hypoglycemic as well.
01-25-2011, 04:34 PM
As you said, NUTRITION is the key to any body goal, especially fat loss. You will only "burn muscle" if your caloric deficit is too far below what is required.
01-25-2011, 07:08 PM
My goal is fat loss by the way. I am dieting. I just wasn't sure about the fasted cardio thing, as I am not down to those last few percentage points yet. I think I have some good answers though so far.
01-25-2011, 09:46 PM
01-28-2011, 05:11 PM
hey rosie so you do a lot of fasting and fasting workingout i would be interrested in hearing about fasting because i think it would be somthing good for me seeing how i gain muscle so easy and can not loose fat or weight at all.that for somebody like me that short fast would help me get toned up?but then again i may be totally off.
01-28-2011, 05:15 PM
I do it almost every morning on the elliptical with a little sugar free caffiene drink right before.....I only go at a moderate pace for prolly ~20 min.....enough to burn off a couple hundred calories.....
Directly after weight training is a good time, too...
I give a f**K!!
01-28-2011, 05:26 PM
I have been doing all my training in a fasted state for a while now, though (BIG DIFFERENCE!); when I was cycling I didn't and would go and train in as little as 10 minutes of chowing down on several thousand calories! - however, this is personal preference, and as I said, you really need to find what works best for you.
If you can't lose fat, then you're not doing something right, primarily with your nutrition and you need to look at this before anything else. I do not advocate fasting - even though it can be good to cleanse your system for a day or so, fasting is not ideal, especially when your body NEEDS food/calories (and if you're not giving them to it, you can go into starvation mode, where your body will fight you and hold onto the fat you have).
01-28-2011, 06:04 PM
01-28-2011, 06:52 PM
01-28-2011, 07:14 PM
01-28-2011, 07:27 PM
always wondered what the exact "definition" of that term meant. It's kinda like the term "empty stomach" I always chuckle a bit when I read a bottle of something that says take on an empty stomach. I mean I eat 7 times a day, I'm eating every 3 hours, i spend half the day eating, when the hell is my stomach EVERY empty other than as soon as I wake up in the morning..?
01-28-2011, 10:33 PM
01-28-2011, 11:11 PM
Also, it's about caloric expenditure. A study sampled a group burning X kcalories in 30 minutes and another group burning the same kcalories in 60 minutes. Each group was monitored for 24 hours post exercise during recovery and found that the higher intensity group used carbohydrates as the major substrate during exercise. However, during the following 24 hours fatty acid oxidation was elevated, whereas the 60m group was subsequently lower. After the 24 hour monitor, total fatty acid oxidation was very close between both groups.
This isn't the exact study I mentioned, but very similar.
Saris, W. H. M., Schrauwen, P. (2004). Substrate oxidation differences between high- and low-intensity exercise are compared over 24 hours in obese men. International Journal of Obesity, 28, 759-765.
OBJECTIVE: Exercise has been proposed as a tool for the prevention of obesity. Apart from an effect on energy expenditure, in particular low-intensity (LI) exercise might also influence substrate metabolism in favour of fat oxidation. It is however unclear what is the most beneficial exercise regime for obese people. We therefore studied the effect of either high-intensity (HI) or LI exercise on 24 h energy expenditure (24 h EE) and substrate metabolism.
METHODS: Eight healthy obese male volunteers (age: 38plusminus1 y, BMI: 31plusminus1 kg/m2, W max: 235plusminus16 W) stayed in the respiration chamber for two nights and the day in-between. In the chamber they cycled either at a HI (three times 30 min in a interval protocol (2.5 min 80/50% W max)) or LI (three times 60 min continuously at 38% W max) protocol with an equicaloric energy expenditure. In the chamber subjects were fed in energy balance (37/48/15% of energy as fat/carbohydrate/protein).
RESULTS: The 24 h EE was not significantly different between protocols. In both protocols, sleeping metabolic rate (SMR) was elevated after the exercise (average+6.7%). The 24 h respiratory quotient (24 h RQ) was not different between protocols. During exercise, RQ was higher in the HI compared to the LI protocol (0.93 vs 0.91 resp., P<0.05), whereas in the postexercise period RQ tended to be lower in the HI compared to the LI protocol (P=0.06).
CONCLUSION: 24 h EE is not differently affected by HI or LI exercise in obese men. Similarly, the differences in HI and LI exercise, RQ are compensated postexercise leading to similar substrate oxidation patterns over 24 h independently of the level of exercise intensity.
01-29-2011, 10:33 AM
01-29-2011, 01:45 PM
And, to expand on what russy said about catecholamines, insulin during exercise is significantly lowered.
Furhtermore, you must take into account net lypolysis over the duration of 24-48 hours, not just during a bout of exercise. This is why HIIT is so succesful.
Myths Under The Microscope Part 2: False Hopes for Fasted Cardio
By Alan Aragon © 2006
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 . 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’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’s a better objective to coincide your carb intake with your day’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’t always cooperate with logic or popular opinion, so let’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’s team observed that carb ingestion during low-intensity exercise (25-45% VO2 max) reduced fat oxidation compared to fasted levels . More recently, De Glisezinski’s team observed similar results in trained men at 50% VO2 max . Efforts to determine the mechanism behind this phenomenon have been made. Coyle’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 .
Carbohydrate’s effect on fat oxidation during moderate-intensity exercise depends on conditioning level
Civitarese’s team found glucose ingestion during exercise to blunt lipolysis via decreasing the gene expression involved in fat oxidation in untrained men . Wallis’ team saw suppressed fat oxidation in moderately trained men & women when glucose was ingested during exercise .
In contrast to the above trials on beginning and intermediate trainees, Coyle’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 [7,8]. 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’ 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) . Similar results to Coyle’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’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’s team investigated the effects of carb ingestion pre & during training in easily one of the best-designed trials on this topic . 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. 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
• At low intensities (25-50% VO2 max), carbs during exercise reduce fat oxidation compared to fasted trainees.
• 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.
• 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.
• At the established intensity level of peak fat oxidation (~63% VO2 max), carbohydrate increases performance without any suppression of fat oxidation in trained subjects.
Melanson EL, et al. Resistance and aerobic exercise have similar effects on 24-h nutrient oxidation.. Med Sci Sports Exerc. 2002 Nov;34(11):1793-800.
Ahlborg, G., and P. Felig. Influence of glucose ingestion on fuel-hormone response during prolonged exercise. J. Appl. Physiol. 1976;41:683-688.
De Glisezinski I, et al. Effect of carbohydrate ingestion on adipose tissue lipolysis during long-lasting exercise in trained men. J Appl Physiol. 1998 May;84(5):1627-32.
Coyle EF, et al. Fatty acid oxidation is directly regulated by carbohydrate metabolism during exercise. Am J Physiol. 1997 Aug;273(2 Pt 1):E268-75.
Civitarese AE, et al. Glucose ingestion during exercise blunts exercise-induced gene expression of skeletal muscle fat oxidative genes. Am J Physiol Endocrinol Metab. 2005 Dec;289(6):E1023-9.
Wallis GA, et al. Metabolic response to carbohydrate ingestion during exercise in males and females. Am J Physiol Endocrinol Metab. 2006 Apr;290(4):E708-15.
Coyle, et al. Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate. J. Appl. Physiol. 1986;6:165-172.
Coyle, et al.. Carbohydrates during prolonged strenuous exercise can delay fatigue. J. Appl. Physiol. 59: 429-433, 1983.
Horowitz JF, et al. Substrate metabolism when subjects are fed carbohydrate during exercise. Am J Physiol. 1999 May;276(5 Pt 1):E828-35.
Febbraio MA, et al. Effects of carbohydrate ingestion before and during exercise on glucose kinetics and exercise performance. J Appl Physiol. 2000 Dec;89(6):2220-6.
01-29-2011, 02:01 PM
All these articles about timing of meals and cardio I agree with, but it pretty much goes completely against the whole calories in calories out equals fat loss theory, no?
What if I eat about 5 snicker bars and take in roughly 1000 calories, but then do enough cardio to burn 1100-1200 immediately afterwards, this is an effective way to lose weight?
Hell no, that's why I agree with the timing of meals and cardio theory. I'm with Easy on this one.
Years ago when I didn't know as much as I know now, I used to do a 2nd cardio session later on in the day, and it just happened to be a few hours after my PWO meal which was a huge 100g plus complex/simple carb meal. Months later I completely quit doing that 2nd cardio session, and only stuck to one cardio session a day, so effectively cutting my cardio IN HALF, but I did this one cardio session on an empty stomach first thing in the am, and I lost more fat on half the cardio when I started doing this.
01-29-2011, 04:47 PM
And for the sake of it, lets also keep exercise intensity constant, at about 75% max HR, which, for someone in any decent shape, is a low intensity.
All that said, fasted cardio IS NOT more efficient than fed cardio in burning fat. Read the summary in the article I posted above, and check out some of the references.
01-29-2011, 05:36 PM
01-29-2011, 08:33 PM
That was with the ingestion of CHO during exercise. Other groups found that CHO ingestion during exercise had no affect on fatty acid oxidation for durations under 120 minutes-thereby finding no difference in substrate oxidation between fasted and unfasted states.
01-31-2011, 07:39 AM
01-31-2011, 12:01 PM
are yall talking about fasted cardio only or fasted working out all so? i sometimes feel like i get better result working out with weights on an empty stomache but that goes against every thing i have heard about needing protien before and after.
01-31-2011, 12:12 PM
01-31-2011, 12:23 PM
hmm interesting, but tiny group (4 people) low activity level (35-55% VO2) and the general parameter was crazy - exercising 20 minutes out of each hour for 4 consecitive hours (with rest inbetween). Not really all that representative. Plus the meal was fat heavy (57%!!) and so would have had slow absorption/digestion, also not very indicative of the average meal of anybody here. And of couse, they only tested O2 utilization, not very directly indicative of lipolysis. Still interesting though.
01-31-2011, 12:58 PM
01-31-2011, 01:10 PM
01-31-2011, 01:20 PM
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