Want to Build Strength and Gain Muscle? Lift Lighter Weights

Lighter weights can be as effective as heavy weights for building muscle.

Posted Jul 13, 2016

Samo Trebizan/Shutterstock
Source: Samo Trebizan/Shutterstock

From the day you're born, until about the age of 30, your muscles will naturally continue to grow stronger. However, by the time you turn 30, you will begin to lose muscle mass, strength, and function. Technically, this condition is known as age-related sarcopenia.

If you remain physically inactive during midlife, you can lose 3% to 5% of your muscle mass per decade after age 30. Unfortunately, sarcopenia often begins to accelerate by the age of 60 and can be a key factor in becoming frail, which increases the likelihood of falls and fractures in older adults. Even for those of us who remain aerobically active, the loss of muscle mass is inevitable—if you don't make some type of strength-resistance training a part of your weekly routine. 

Great News! Lifting Lighter Weights Is Highly Effective 

When I was younger, I loved lifting weights. However, as I've gotten older, I don't have the oomph to lift heavy weights anymore. After a cardio session at the gym, most of the time, I find an excuse to avoid resistance training. Even though I know I 'should' lift weights, it feels like a chore. I realize now that I have subconsciously fallen into a faulty 'all or nothing' mindset. Knowing that I'm not going to lift heavier weights, I'll say to myself, "why even bother, because lifting lighter weight is pointless."

If you're like me—and have put off strength training because lifting heavy weights seems daunting—I have good news. A new study from McMasters University reports that lifting lighter weights to exhaustion can be as effective as lifting heavy weights.

The July 2016 report, “Neither Load Nor Systemic Hormones Determine Resistance Training-Mediated Hypertrophy or Strength Gains in Resistance-Trained Young Men,” was published online in the Journal of Applied Physiology.

Tatyana Vyc/Shutterstock
Source: Tatyana Vyc/Shutterstock

The study presents the latest findings in a series of studies that started in 2010. This research counters the decades-old message that the best way to build muscle is to lift heavy weights. In a statement, Stuart Phillips, senior author of the study and professor in the Department of Kinesiology, said, "Fatigue is the great equalizer here. Lift to the point of exhaustion and it doesn't matter whether the weights are heavy or light."

For this study the researchers recruited two groups of men—all of them experienced weight lifters—who followed a 12-week, whole-body regimen. One group lifted lighter weights (up to 50 per cent of maximum strength) for sets ranging from 20 to 25 repetitions. The other group lifted heavier weights (up to 90 per cent of maximum strength) for eight to 12 repetitions. Both groups lifted to the point of muscle failure.

Researchers analyzed muscle and blood samples and found gains in muscle mass and muscle fiber size, a key measure of strength, were virtually identical. Phillips concluded, 

"At the point of fatigue, both groups would have been trying to maximally activate their muscle fibres to generate force. For the 'mere mortal' who wants to get stronger, we've shown that you can take a break from lifting heavy weights and not compromise any gains. It's also a new choice which could appeal to the masses and get people to take up something they should be doing for their health."

Another interesting finding of this study was that none of the strength or muscle growth observed in participants was related to testosterone or growth hormone. Although this study was conducted on younger men, the findings suggest that lifting light weights to muscular exhaustion is beneficial for people of all ages and genders.

Conclusions: More Research on the Mechanisms of Building Muscle Is Needed

This research shows that the short-lived rise in testosterone or growth hormone is not a driver of muscle growth. However, more research is needed to pinpoint the exact underlying mechanisms that drive gains in muscle mass and physical strength. Stay tuned! 

To read more on this topic, check out my previous Psychology Today blog posts, 

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