Thread: New Dude says HI to Everyone and asks long question

I'm a 20 yr old male who likes weight-lifting. I really like riding bicycle too for long times 30min - 2hrs. I'm reading that cardio hurts body building if done for a half-hour or more. As you know, your body looks at muscle as a liability because it consumes so many calories to maintain. When you cut back on carbs and increase cardio, your body starts consuming its fast-twitch fibers (the valuable size and strength fibers) as it preserves the slow twitch fibers it needs to do the cardio. And long duration aerobics produces corisol, a catabolic agent that breaks down muscle porteins. Worse, as your strength diminishes due to less fast-twitch fibers, the amount of weight you can lift decreases. With less load, your body starts dumping even more muscle as it perceives it as unnecessary. This is known as the dreaded Catabolic Spiral. Just look at marathoners, their body has literally eaten itself alive. My real question is that do you think its ok for me to bike hard for an hour or longer and not worry about losing muscle size. I lift mainly with my chest. I want six pack abs,big arms, big chest, big strong back, and ok legs. I dont need huge legs and was wondering if biking would only hurt my legs or if it would take away from the rest of my body. I way 195lbs and am 6'2" and in average shape. I roof so I run and stand all day on my legs so they get good exercise. Biking helps work out my lungs therefore I can breath heavier (deeper) and easier and that's mainly why I bike. Elliptical machines help me breathe better to and that's a great feeling (breathing) so I constantly want to power up my lungs by biking or getting on an elliptical machine. When I get done weight lifting I dont feel my lungs work as hard and well, just my muscles i've been workin on. Will all the cardio I LOVE to do hurt my body building in my upper body?

Welcome to IM.