Question: I read somewhere that using a vibrator can sometimes weaken the muscles inside the vagina. Is this true? I masturbate using a vibrator sometimes daily, so I'd like to make sure that my kegel exercises haven't been in vain. Especially since it feels like I'm not as strong as I used to be, (which may or may not be a figment of my imagination.) Thanks.
Answer: I have not heard this myself and would tend to believe otherwise. Vibrations may relax muscles but I have not heard they cause any degeneration of muscle tissues. Jackhammers and the like are harmful but they are a lot more powerful than a personal vibrator.
Your muscles may have been tight as a result of atrophy, lack of use, and now, between using a vibrator, orgasms, and perhaps inserting things vaginally, the muscles are more relaxed and flexible, and your hymen may be stretched open more. The pelvic muscles just need to be strengthened by use.
You might do your Kegels with your fingers or another object inserted to get a sense of how much you are squeezing. Make sure your stomach muscles remain relaxed. You can tell if they are relaxed by placing your hand on your stomach, over your navel. You could be doing them wrong so they are not doing what you are expecting them to. You may need to do them more often too. There are weight and barbells made for Kegels but they can be pricey.