Everyone knows that if you want to bulk up and get big muscles, you grab heavy weights and do low reps, but if you just want to tone up and get lean, you pick up some light weight and go to town with high reps. It's common knowledge. That just makes sense, right?
Mm, we'll think about that later, but first, what do people even mean by "bulking" or "toning" or "leaning out?" When people use terms like these, they usually have some role model in mind (maybe Arnold Schwarzenegger or Jillian Michaels) who they would describe as being "bulked up" or "super toned" or whatever sounds good at the time, then decide they want to look like that person. The truth is, all these terms are different ways of saying one thing, whether you know it or not: you want to build muscle.
People think of "toning up" as simply turning fat into muscle (which is impossible), but what that type of desire really necessitates is increasing muscle mass and decreasing fat mass to achieve a desired appearance. Guess what people who participate in bodybuilding competitions want to do? Increase muscle mass and decrease fat mass to achieve a desired appearance.
No way, it's the same thing! :o
When you're doing sets of 25 bicep curls with a 5-pound dumbbell, your muscle isn't saying to itself, "Ah yes, soon I will achieve maximum tone-age!" Neither is it saying "I'm going to get stinkin' HUGE" if you're struggling to get 4 reps out of a 50-pound dumbbell.
So how is it that some people build large muscles while others stay more slim and leaner in appearance? Weight training styles have a little to do with it, but it's mostly how you eat that determines how your body will end up looking. A person who wants to maintain a slimmer physique would eat fewer calories per day than someone wanting to add 10 pounds of muscle to their frame. If you want control over your physical appearance, the key is to remember to eat for the body you want, not the body you have.
Now, with all that said, how many reps SHOULD you be doing as you hit the weights? At this point, I would want my personal training clients to think more about function over form. Training in different rep ranges DOES affect how your muscles grow, just not how it's commonly talked about. Let me break it down in 3 parts, and from there you can choose what best fits your lifestyle:
1. For pure strength gains, it's suggested among fitness professionals to work to about 6 or fewer reps.
2. For building both strength and size in your muscles, work in about a 6-12 rep range.
3. For increasing muscular endurance, work in a 12+ rep range.
So, toning friends, don't be afraid to reach for some heavier weights. I promise you won't wake up the day after a heavy workout looking like Thor (trust me, I've tried). Plus, as your muscles grow, they will actually increase the rate at which you burn calories after exercise. Awesome, right?
Keep in mind, the purpose of this article isn't to be a one-size-fits-all guide for everyone. Rather, I want to encourage you to be more conscious of what you're doing when you work out and make suggestions to help you reach your goals more effectively. Please feel free to ask me about a more individualized approach or do your own research and let me know what you find!
I'm always learning, too :)