? 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.
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Layne Norton posted (on another forum) an abstract from some research he was reading at the time. It concluded that carbs before cardio in trained individuals had no impact on fat oxidation during the cardio session. I believe up to 150 grams of carbs were used in the experiment. He’s not a believer in fasted cardio.
[quote]elusive wrote:
Layne Norton posted (on another forum) an abstract from some research he was reading at the time. It concluded that carbs before cardio in trained individuals had no impact on fat oxidation during the cardio session. I believe up to 150 grams of carbs were used in the experiment. He’s not a believer in fasted cardio.[/quote]
Neither am I anymore even though I would have told you differently even 3 years ago. Overall daily activity level has more to do with the results seen when dieting than whether you don’t eat before morning cardio, something that I now think may actually be very catabolic to muscle tissue if you are doing so for extended period of time (up to an hour or more) on an empty stomach.
The problem arises because there are so few studies done on healthy active individuals with more lean body mass then average who aren’t obese.
[quote]Professor X wrote:
elusive wrote:
Layne Norton posted (on another forum) an abstract from some research he was reading at the time. It concluded that carbs before cardio in trained individuals had no impact on fat oxidation during the cardio session. I believe up to 150 grams of carbs were used in the experiment. He’s not a believer in fasted cardio.
Neither am I anymore even though I would have told you differently even 3 years ago. Overall daily activity level has more to do with the results seen when dieting than whether you don’t eat before morning cardio (something that I now think may actually be very catabolic to muscle tissue if you are doing so for extended period of time (up to an hour or more) on an empty stomach.
The problem arises because there are so few studies done on healthy active individuals with more lean body mass then average who aren’t obese. [/quote]
I couldn’t agree more. I’ve done different types of diets and cardio styles. All basically resulting in the same way. Cardio is just a means to burn some extra calories throughout the day, which helps put the body in an energy deficit (which is better than putting yourself in a calorie deficit entirely through eating less).
Ironically enough, Alwyn Cosgrove posted these same studies and more in his Fat Loss Manual.
The studies and his own personal experience training thousands of people has shown that there is no diffence in fat loss between fasted cardio and non-fasted cardio. And as Professor X said, there is a chance that the fasted cardio may affect muscle gains or cause muscle catabolism.
Some will continue to argue that fasted cardio is better. For them, it may work fine because of various factors (amount and intensity performed, amount of muscle mass, etc.).
At the very least, it’s a good idea to take in a small amount of amino acids/protein (10-15 grams) prior to your “fasted” cardio.
Overall, I also believe that it’s the total amount of activity done that influences fat loss the most.
From my own experience, the more active I am (weight training 3-4 days a week and additional stuff on top of that), the easier it is to get lean or stay lean.
It always seemed to make sense that you’d burn glycogen over fat if stores were up, and there’s been so much back and forth on this.
I feel like I’m wasting my time if I do cardio later in the day after a couple of meals vs. first thing in the morning on an empty stomach.
This research is interesting, and if that’s the case then I guess there’s no reason not to do cadio whenever.
Optimally, I guess you’d want to wait at least 2 hours after a meal, if for no other reason than to make sure you aren’t diverting blood flow towards digestion…
[quote]SkyNett wrote:
It always seemed to make sense that you’d burn glycogen over fat if stores were up, and there’s been so much back and forth on this.
I feel like I’m wasting my time if I do cardio later in the day after a couple of meals vs. first thing in the morning on an empty stomach.
This research is interesting, and if that’s the case then I guess there’s no reason not to do cadio whenever.
Optimally, I guess you’d want to wait at least 2 hours after a meal, if for no other reason than to make sure you aren’t diverting blood flow towards digestion… [/quote]
My sleep schedule has been “irregular” for years. I very rarely (except for weekends) actually sleep for an entire 8 hours. That means there is no “fast” for someone like me who is eating every 2-3 hours and may only sleep up to 3-4 hours at a time. That means “fasted cardio” loses its meaning in that context.
Obviously, loading up on simple carbs right before doing cardio makes little sense. I used to see a guy eat a banana every single day seconds before he hopped on the treadmill. Aside from making no sense to do that, I never saw him get much leaner (or gain any muscle).
I agree, the goal should be to avoid having a full stomach and BCAAs do make sense if you do perform cardio first thing in the morning and you want to avoid running completely on empty…as long as your overall food intake is low enough to actually promote a loss in fat/body weight.
As I’ve said before, although I lack the experience of some of you, I still think the body is more apt to burn (prefer?) whatever tissue is has become efficient at handling, and by that I mean storing/building fits into that category.
If you have mostly LBM because you have been building slabs of it and training for a while (and, have learned how to maintain this LBM), you will use a higher ratio of LBM than fat to fuel such cardio sessions.
I only say this, however, based on every big lifter on here claiming that bouts of cardio did not simply strip off the fat, that they also lost muscle.
[quote]B rocK wrote:
years ago when I cut down (improperly) i used 25-45min of fasted cardio 2-3x a week…
at the beginning of my cutting phase it seemed to work; but then i got carried away; lost a bunch of weight (read: muscle) and ended up being weak.
if i plan to ever cut weight again it will be done with nutrition instead of added cardio. [/quote]
X2 I used fasted cardio this summer, and it tore down my muscle very quickly. I’m just going to be meticulous with my diet next time I lean down, then if necessary add in some cardio.
I think the type of cardio is also relevent, and a lot of folks just skip over that. The impression I’ve always had was that doing steady state will burn how ever many calories your burn during the session (which is maybe a couple of hundred on a good day I would imagine). However HIIT will create an elevated metabolism for (I believe) up to four hours.
Considering how much actual work HIIT is compared to just plodding along doing steady state at a mile an hour, I know there’s no way I could ever do that on an empty stomach and have it be productive. Still, for those who try to eat no carbs before doing their cardio, you would actually have to figure out just how long ingested food takes to become readily available as fuel to assess whether carbs or no carbs pre-cardio would have any real effect.
I’m getting to the point I think most people over emphasize timing and under emphasize totals. This goes for everything from cardio to eating to training. Total macro-nutrients trump eating more meals a day at exacting times, total activity daily trumps timing of a cardio session, est.
Not saying timing isn’t important but they are a way to fine tune, not build a program.
[quote]DoubleDuce wrote:
I’m getting to the point I think most people over emphasize timing and under emphasize totals. This goes for everything from cardio to eating to training. Total macro-nutrients trump eating more meals a day at exacting times, total activity daily trumps timing of a cardio session, est.
Not saying timing isn’t important but they are a way to fine tune, not build a program.[/quote]
[quote]SkyNett wrote:
DoubleDuce wrote:
I’m getting to the point I think most people over emphasize timing and under emphasize totals. This goes for everything from cardio to eating to training. Total macro-nutrients trump eating more meals a day at exacting times, total activity daily trumps timing of a cardio session, est.
Not saying timing isn’t important but they are a way to fine tune, not build a program.
Good point - definitely agree with that. [/quote]
I agree, too.
And no offense to the authors, but the more I read the more I realize - not only myself but - how many of them don’t know, either. I honestly feel like I read one guy say something and for the next 5 authors, that same point will be parroted without evidence.
[quote]The Mighty Stu wrote:
I think the type of cardio is also relevent, and a lot of folks just skip over that. The impression I’ve always had was that doing steady state will burn how ever many calories your burn during the session (which is maybe a couple of hundred on a good day I would imagine). However HIIT will create an elevated metabolism for (I believe) up to four hours.
Considering how much actual work HIIT is compared to just plodding along doing steady state at a mile an hour, I know there’s no way I could ever do that on an empty stomach and have it be productive. Still, for those who try to eat no carbs before doing their cardio, you would actually have to figure out just how long ingested food takes to become readily available as fuel to assess whether carbs or no carbs pre-cardio would have any real effect.
S
[/quote]
I agree, the type of cardio is important.
I wouldn’t want to do more intense steady state cardio (like jogging at a decent rate) on an empty stomach for extended periods of time. But, doing lower intensity steady state cardio (like a brisk walk) for 20-30 minutes first thing in the morning works quite well.
HIIT is great for athletes, but depending on your resistance training routine it can cut into your recovery abilities or just be impractical.