Can someone who knows about fat-burning answer this?

[LeeJunFan]

OK, correct me if I'm wrong on any of these comments, when doing high intensity cardio your body will use glycogen from your muscles as energy, when that glycogen is gone your body turns to fat stores, why will your body stop using fat stores and eventually burn lean muscle?
When doing low intensity cardio (like walking), your body uses fat stores as energy, heres my question, if you were to do low intensity cardio for a long time (just for example, say you were walking at a moderate pace, non-stop, for 3 hours) would you constantly use fat stores as energy or would you burn muscle, if so why does this happen?

 

[juve]

OK, correct me if I'm wrong on any of these comments, when doing high intensity cardio your body will use glycogen from your muscles as energy, when that glycogen is gone your body turns to fat stores, why will your body stop using fat stores and eventually burn lean muscle?
When doing low intensity cardio (like walking), your body uses fat stores as energy, heres my question, if you were to do low intensity cardio for a long time (just for example, say you were walking at a moderate pace, non-stop, for 3 hours) would you constantly use fat stores as energy or would you burn muscle, if so why does this happen?

1)High intensity: this is a type of anaerobic training meaning that the primary fuel is not fat at all, but to sustain such an activity you would need an abundance of glucose (stored as glycogen [liver and muscle) and plasma glucose] or muscle (protein). Fat is burned during such an activity at diminishing rate, while glycogen or gluconeogenesis (breakdown of muscle tissue to generate glucose) are at prime utilization.
2)Low intensity: aerobic activity, that can be sustained predominantly by fat mobilization/oxidation. But as time of excercise progresses bodily hormonal response starts to adjust. Cardio, even low intensity is stressful, hence come in glucocorticoids to enhance your ability to cope with the nset of stress. Metabolisis of fatty acids generates harmful metabolites (perroxides, reductive oxygen species, etc) which are mostly cleared by the body immune/autoresponse system. But some still remain and they do cause muscle cell degradation and mutation. Not to mention as you go on at a low pace, the abundance of free fatty acids declines, thus body opts for an alternative (muscle, glycogen).

 

[sirbadass]

wow.

so basically, what you're saying, is that for optimal fat burning without sacrificing any muscle, a person shouldn't do any cardio at all. am i wrong in saying that?

and the best thing to do, for burning fat and retaining as much muscle as possible, is eat a high protein meal with a serving of simple carbs or sugar pre-workout and use the rest of the day for burning fat, albeit at a slow pace? i.e., diet has more to do with burning fat that doing cardio.

 

[ProtienFiend]

and the best thing to do, for burning fat and retaining as much muscle as possible, is eat a high protein meal with a serving of simple carbs or sugar pre-workout and use the rest of the day for burning fat, albeit at a slow pace?

no... definitely not simple carbs... as insulin stops liposis

 

[sirbadass]

ok, thanks p.f.

so no simple carbs. what about fructose (as you mentioned on the other thread)? does fructose produce a spike in insulin as well?

 

[ProtienFiend]

ok, thanks p.f.

so no simple carbs. what about fructose (as you mentioned on the other thread)? does fructose produce a spike in insulin as well?

nope.. its GI is about 30 or so.... simple carbs are usually considered 70+

 

[Ulter]

If you want to use simple carbs in your diet, and you should if you're going to weight train, then you should use Glucorell R to dispose of them quickly and shut down high insulin levels faster. Like Sirbadass said, your burns no fat in the presence of insulin.

 

[sirbadass]

ulter, am i correct in thinking that simple carbs should be used only in the post-workout recovery shake?

 

[tatertoos]

That's my practice, with plenty of ALA/biotin, of course...

 

[sirbadass]

let me see if i have this right now...

protein with a serving of fructose 1hr pre-workout (ex. tuna and apple),
2:1 ratio of sugar to protein immediately post-workout for recovery followed 1hr later by a high protein with a serving of complex carbs meal.

is that about right?

tatertoos, what are/is ALA/biotin?