I'm planning on getting into road biking fairly seriously for the first time this summer. I'd also like to gain 15-20 pounds of muscle through strength training workouts at the gym. Obviously biking could be replaced by any aerobically challenging activity, but I'm posing this question here: can it be done? One thing I've read is that it's best to keep high heart-rate workouts, such as bike rides, to under one hour to prevent your body from reaching into protein mass for energy. One hour rides aren't exactly what I was hoping for. One thing I've thought of is just really eating a ton all summer, though I'd rather not have to be in constant compulsive pig out-mode to achieve my goals.

What do you think?