I think all women are taught somewhere in their formative years that if you lift weights, you'll grow up to look like a dude. And if we aren't taught that, somehow, the idea gets put in our brains. Maybe it's just one of the irrefutable truths that women just know, like all men are jerks and shopping cures depression.
My husband used to be a really small guy, 5'8" and 135 lbs. He got into weightlifting to gain weight, but he found that he enjoyed it so much that he wanted me to do it with him. I refused, of course, because I was trying to
lose weight, not look like Arnold Schwarzenegger. No matter how many times he tried to convince me that I wouldn't bulk up from lifting, I held firm to my convictions. It wasn't until I went to one of his powerlifting meets and saw some of the girls competing that I finally admitted to myself that I might be wrong. Those girls looked better equipped for bucket tosses and front flips on a cheerleading mat than for deadlifts and bench presses in the gym.
The truth is, weightlifting is an essential part of any fitness regimen, and growing muscle to the point of bulk is a lot harder than it sounds. It doesn't just happen. You have to eat an insane amount of calories to build that much muscle. (To get from 150-180, my husband had to consume upwards of 4,000 calories a day!) Strength training, in combination with a healthy relatively low-cal diet, will build lean muscle and that sculpted toned look that we all wish for.
When I talk about strength training, I'm not referring to little 3-10 lb hand weights. Those are better suited to holding during a cardio routine. I'm talking about
real weight. The kind where you break a sweat after one set, and your muscles feel like jelly by the end of your workout. FYI - if you're not sore for a few days after a strength workout, you need to step it up. That feeling of soreness comes from your muscles repairing themselves, so if you don't feel it, then your workout wasn't strenuous enough and you didn't reap the benefits.
Vigorous weightlifting burns 8-10 calories per minute, so a 30 minute session burns roughly 240-300 calories. That's slightly less than intense cardio like running, but weightlifting has a much larger afterburn (the calories burned after the workout is over), since your muscles have to repair themselves and the body uses calories to do that. Muscle also requires more calories to maintain than fat does, because muscle is constantly being broken down and rebuilt, even when you aren't working out. Fat just kind of sits there, being fat. So, the more muscle you have, the higher your metabolism. It's actually because of the fact that muscle mass increases your metabolism that body builders and powerlifters have to consume so many calories. They've pretty much burned the food off before it hits their lips. There are guys on my husbands team that are 230 lbs of solid muscle, but have to eat loaded large pizzas drowned in ranch dressing and olive oil in order to keep their weight up.
Those girls at the powerlifting meet who looked like cheerleaders, probably were. Anyone who can toss another human being into the air and then catch them, has to have seen their fair share of barbells. If you ever look into the workout regimens of Victoria's Secret models, you'll find that they involve a LOT of weightlifting. They actually spend their lunch breaks doing lunges down the hall with a squat bar! (Little known fact - supermodels are crazy-strong, like gorillas.)
You can lose weight and be thin without strength training, but you'll never achieve that elusive "toned" look that you're after without some heavy lifting. You'll just walk around being skinny and jiggly, what my husband I refer to as a skinny-fat person. And you'll always have to count calories because your metabolism will be slow as molasses.