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Lighter Weights Create New Muscle If You Do Enough Reps

Weight Training News: Size Doesn't Matter

A little muscle tone is a good thing, and based on new research it looks like lighter weights can help you achieve that goal. A new study, conducted at Canada's McMaster University, found that it's not the size of the weights that matter but rather fatiguing the muscle. To work your muscle to the magic exhaustion point to stimulate your muscle growth, you can either lift heavier weights for fewer reps or lighter weights for more reps; as long as you reach "muscle fatigue" you will be building muscle fibers.

McMaster's associate professor of kinesiology Stuart Phillips explained the process to Science Daily:

"Rather than grunting and straining to lift heavy weights, you can grab something much lighter but you have to lift it until you can't lift it anymore. We're convinced that growing muscle means stimulating your muscle to make new muscle proteins, a process in the body that over time accumulates into bigger muscles."

This is good news for a variety of reasons. While working with heavy weights can make you feel like a super toughie, they can be hard on your joints. Creating joint pain is not what you want out of a strength training session. Plus, lighter weights are less intimidating, so if you're not ready for 20-pound dumbbells no worries. Just be sure to do enough reps to thoroughly exhaust the muscle.

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Join The Conversation
Splintera Splintera 7 years
Not to mention, lifting heavier weights increases bone density: "our data would suggest that a high volume low-load resistance exercise paradigm may serve as an excellent training paradigm to attenuate age-related sarcopenia, and other frailty and wasting conditions by maintaining and/or inducing skeletal mass while at the same time minimizing the potential for both orthopaedic and soft tissue injury in these susceptible populations."
SummerB88 SummerB88 7 years
I'm not sure about what to believe--I prefer heavier weights myself (less reps partly due to laziness..? haha) but i DO know that that's MY SCHOOL! Wooooot! :) MAC is where it's at!
Sasseefrass Sasseefrass 7 years
As well, the study didn't measure real training effect over a long period of time. They simply measured specific biological markers after three separate sessions doing leg extension at two rep extremes. (Very heavy and very light.) Interestingly enough, the commonly prescribed exercise protocol for growing bigger muscles is somewhere in the middle of the two rep ranges used and wasn't tested in this particular study at all.
Spectra Spectra 7 years
That's great, but I'd rather be efficient and do 10 reps of heavy weights instead of a couple hundred reps of light ones. Tracy Anderson is all about the light weights/tons of reps and I hate her workouts.
Sasseefrass Sasseefrass 7 years
The link to the original study abstract was in the 'Story Source' section below the article. Quote: "Fifteen men (21±1 years; BMI = 24.1±0.8 kg/m2) performed 4 sets of unilateral leg extension ..."
jaxsprat jaxsprat 7 years
Um...did I miss something where does it say only 15 people were used in this study?? I would be a bit surprised if McMasters University didn't conduct this over a long period of time ( the university has such a good reputation). I seems to be this is their findings from said study.
Sasseefrass Sasseefrass 7 years
I'd be suspicious of the results of a study that uses only 15 test subjects. I'd be interested to see it done again with a lot more people AND have those people divided into groups based on whether they're just beginning or whether they've weight trained for at least a year. A beginner is going to get results just from picking up a weight and knocking out a set or two. Someone who's been resistance training regularly - say, 3 times a week - for at least a year using quality programming is going to be much more specific in what she needs to get results. And like the previous poster said, I prefer to knock out a few hard reps that take me to failure than spend my time doing tons of reps with light weight. Keep in mind as well that lifting for higher reps carries it's own risks: A higher number of reps carries an increased likelihood of repetitive stress injuries. As for heavier weights increasing the risk for joint strain: You don't start beginners lifting maximal loads. You build up using lighter weight/higher reps and progress to higher weights/lower reps once appropriate base strength and muscle balance is achieved. People should be switching up their program every 4 weeks or so. Use a different rep range as well as different exercises. They'll find they get better results AND minimize their chance of injury by doing so instead of continuing to train within one rep range because some study said to.
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