Question about Whey Isolate and absorption? carbs necessary? - Page 2

No I realize cortisol has many other functions than just promoting gluconeogenesis. I was just mentioning that because that's the explanation for the 'carbs after workout' theory. So you're saying that depleting (and restoring) stored muscle glycogen has no effect on cortisol levels? Does it (depletion of muscle glycogen and blood glucose) also have no effect on gluconeogenesis (and the 'unwanted' muscle protein breakdown)?

In other words, would the theory be sound if it weren't for cortisol tossed in this mix? I've always understood that physical exercise increases cortisol levels, and that cortisol promotes gluconeogenesis so I assumed (perhaps incorrectly) that they were involved in the same process. If it isn't, and the fact is merely ancillary, then that would explain the confusion.

Thanks for clarifying your stance. No need to get E-motional over nothing.

1) Yes you don't. However, the whole theory goes that some carbohydrates will absorb faster than others so why not replenish glucose and glycogen in the most efficient way? Even if it takes longer than 5 minutes to digest food, wouldn't it still be better to get in some simple carbs immediately which digest within 30-40 minutes than to wait a couple of hours without eating them at all? The scenario presumes that the glucose and glycogen is exhausted so you'd have to find other sources of energy otherwise.

2) I tend to agree that timing is overrated for most people, but the OP asked about protein alone vs protein with carbs after a workout so I think he deserved some information that he could apply to his own situation. As for me, I have a pre-workout meal of oats so I probably have enough energy to last me through most workouts. As a result I usually don't worry about timing too much and just make sure I get some good whole food in sometime after.

However, there were a couple of situations where I think I benefited from the quicker intake of carbs PWO and that's 1) where I went all-out training without having eaten much earlier in the day (like training in the morning) and 2) where I was on a ketogenic diet and my carb intake was much much lower and more specific (carb timing *is* very important when it comes to specific ketogenic diets).

3) Congrats. I also know a lot of people who have skipped the rigor of following an exact schedule post workout and have gained just as well as when they did fuss about ratios and timing. Still, I think it was more helpful to give the OP the information and let him decide whether or not to do it since his needs and goals might be different.

There's a few issues here. Firstly, gluconeogenesis is caused by a lot of hormones other than cortisol. Secondly, glycogen depletion doesn't happen in a single workout unless the workouts consist of running 15 miles. Thirdly, the effect of gluconeogenesis is overstated and it doesn't mean muscle tissue is breaking down.

To answer your questions:

Carbohydrate ingestion does have an acute effect on cortisol levels with the magnitude being concomitant with the amount of carbohydrates. This is not dependent upon glycogen restoration (in other words, energy balance plays the big role here).

Depletion of glycogen and serum blood glucose will increase gluconeogenesis but this does not mean muscle tissue is being converted into glucose. I think that's where you're confused.

Yeah I think that explains it. While the muscle tissue isn't converted to glucose, isn't it still being catabolized and used for energy using a different cycle?

Not all proteins are muscle tissue.

It takes a very long time before muscle tissue is catabolized. Don't worry about it.

You're right on all points. Of course if he's an athlete who is constantly training, he'd need to worry about that I guess. I was just assuming he's a recreational lifter like the rest of us who do 3 days a week at most in the gym.

http://www.flexonline.com/food_fixes>nutrition/nutrition/65

is this what you guys are talking about?