Ok so I get asked this often from my training clients. "If I lift too much weights will I get really HUGE?"
I read an article today from Bodybuilding.com and they addressed this VERY subject. (February 5, 2014 issue) The answer is simple: NO, not unless you are REALLY trying to get BIG.
I tell clients this: if you were driving through McDonalds every day ordering a Big Mac super sized meal with a large chocolate shake, the chances are that you would start to put on a lot of weight very quickly. This is because you are doing an extreme behavior for the purpose of gaining weight. (This is VERY unhealthy by the way.) I use this same analogy for weight training. If you want to get really big let's say for a competition or an event then you will need to lift HEAVY weights 5 or 6 days a week and have stellar nutrition to go with it. You would have to be doing heavy barbell, dumb bell, plates, etc. to really bulk up. It takes many months/years to achieve this kind of muscle.
As far as nutrition, you would have to be a supplement queen or king and really KNOW your stuff. Creatine, Protein, Betaine, etc are all designed to give you more muscle mass and you would most likely need to study how these kinds of supplements work to get you where you want to be.
This is FAR BEYOND the scope of my business. I don't claim to know much about supplements except for the Beachbody products I retail. That being said, if you are weight training with me for sports conditioning, HIIT training, or just to build muscle, you will not get HUGE. That's not my thing first of all, and second, that's beyond the scope of what I do as a trainer and coach.
The same goes for riding the bike. I had people in my indoor cycling classes tell me they are worried that the bike will make their legs big. Again, I tell them they would have to be squatting with a LOADED barbell on their back and doing all the nutrition that goes with being a body builder or power lifter. Definitely NOT in a cycling class. If anything, it will make your legs thinner and more toned, NOT huge.
I hope this puts your mind at ease! Need a trainer or triathlon coach? Message me at marinewifemultisport.com!