"Never exercise for over 45 minutes"

[Yojimbo]

I don't see your body catabolizing itself if the two primary energy sources are available -fat and carbs.

Protein is a very poor energy source. The body only uses about 5% of the protein it takes in as energy because it creates waste products which then must be expelled. You would have to be in poor shape nutirionwise for your body to dig into its muscle. You would have to go several days without eating.

I would be more worried about the prolonged effects of elevated cortisol levels due to stress. Increased basal levels of cortisol would mean you are constantly exposed to its catabolic effects. Unless you are swimming the English channel, stress is more likely to burn your muscle than a workout.

This is true, basically if you eat enough carbs and fat you can prevent the the use of protein and muscle.

I have a feeling that most of these studies are coming from people who are either limiting their diets to loose weight or not properly adjusting their diets to their activity level.

[WillBrink]

This is true, basically if you eat enough carbs and fat you can prevent the the use of protein and muscle.

Limit yes, prevent no. It's simply a matter of energy systems and that can't be totally manipulated via diet. It's why studies generally find long distance runners need as much or more protein then strength athletes, because they can use 15% of their energy recs from protein, and if they aint eating it, it's coming from their muscle mass.

Strength athletes, as a rule, tend to eat more protein than they actually require, while endurance athletes tend to eat far less protein than they require, if left to their own devices.

[Heavy Metal]

You want an eample of catabolism?

AT Thru Hikers that burn from 6500 to 8000 calories a day.

Cut, fit legs and twigs for arms.

[WillBrink]

You want an eample of catabolism?

AT Thru Hikers that burn from 6500 to 8000 calories a day.

Cut, fit legs and twigs for arms.

Word.

[B52U]

How does this explain ultra runners who regularly run not just 45 minutes but 10 HOUR training runs and don't retain fat.

[Yojimbo]

I think those AT Thru Hikers are the extreme.

My point is is simply that if your training sessions last more than 45 minutes you don't really need to worry about catabolizing your muscles if you are eating enough and supplementing your diet properly.

I am also not saying that you have to train longer than 45 minutes to get the best results. I am only saying the theory that it's best to limit your training to less than 45 minutes is flawed because it does not take a lot of other factors into consideration.

[Grizzly16]

I am only saying the theory that it's best to limit your training to less than 45 miuntues is flawed because it does not take a lot of other factors into consideration.

This.

Just about any one sentence prescription for how to do an activity is flawed.

[WillBrink]

How does this explain ultra runners who regularly run not just 45 minutes but 10 HOUR training runs and don't retain fat.

Ultra runners are the perfect example: they don't don't retain muscle, tend to be injured more than any athlete I know of, have compromised immune systems, and generally look like sh%& to boot. Regarding your comment on retention of fat, although they are generally lean, they are not as lean as sprinters for examples in general, who carry more muscle and less bodyfat:



Vs

[WillBrink]

This.

Just about any one sentence prescription for how to do an activity is flawed.

"Regular exercise is good" is one sentence and not flawed! I agree, just breaking chops.

[Zhurdan]

Ultra runners are the perfect example: they don't don't retain muscle, tend to be injured more than any athlete I know of, have compromised immune systems, and generally look like sh%& to boot. Regarding your comment on retention of fat, although they are generally lean, they are not as lean as sprinters for examples in general, who carry more muscle and less bodyfat:



Vs

Curious. Is that because long distance runners primarily run with their legs and sprinters run with their whole body?

Seems like the long distance guys hardly move their upper body, whereas sprinters look like their whole skeleton is about to jump out of their bodies from head to toe.