
Originally Posted by
snowfox;41***77
That's exactly what I don't understand. If I would drink a protein shake before doing cardio, wouldn't the protein (bcaa's and others) be used for energy instead of fat? I used to do cardio with an ECA stack but I ran out of ephedrine so I'll just have to make do with caffeine.
No, protein will not be used as an energy source unless you do High Intensity cardio on an empty stomach, if you keep the intensity low for 30-40minutes then you'll be fine. Here's a simplistic reason why, to use protein for energy your body needs to go through several steps, first it has to break down muscle fiber into it's constitute amino acids, then transport the AAs to the liver where they are converted to alanine, then through gluconeogenesis then are converted to glycogen and burned for energy, this process is very inefficient because of the amount of energy required vs. energy gained.
Another thing to consider is that your body will only burn muscle if it's amino acid pool is empty, but by drinking a protein shake with bcaas you are filling up that AA pool, which means the bcaas will be used first before muscle, though this shouldn't even be a factor unless you are doing high intensity
Also, caffeine has been shown to have slightly anti-catabolic properties, meaning it shifts your body away from using muscle for energy
And btw, I drink about 2 to 3 shakes of whey isolate depending on how much I eat. But my protein intake more or less amounts to 150gr a day.