There has long been a myth that if women lift heavy weights they will become bulky. Overly built like a linebacker. I am here to finally put that myth to bed. It is very difficult for women to become big and bulky like a man. The amount a estrogen and lack of testosterone that a woman produces hinders the bulky effect.
Now there are female bodybuilders who do capture that look but it is intentional. They work extremely hard year round to achieve those feats. Pushing their body's to limits that are difficult for many to duplicate. Some may even take a supplement to tone down their estrogen levels while increasing their testosterone. The simple fact is, if you're working out and start to notice you're getting a little bulky, just adjust. I promise you, you're not going to wake up one morning with 15 lbs of muscle after one strength training workout. I've tried and it hasn't happen yet.