Lighter Weights versus Heavier Weights

Guest post by Enid Fox, BA, ACSM Certified Health Fitness Specialist, ACSM/ACS Certified Cancer Exercise Trainer

In my last FitNet message I stressed the importance of increasing muscle mass to manage weight. Increasing muscle mass matters more than losing fat. You can not lose fat if you are losing muscle.

If you diet without building muscle, or lose weight too fast, the loss of muscle makes substantial weight loss nearly impossible. Cardio exercises are not enough to enhance weight loss or weight maintenance. Consistent resistance training is an essential part of any weight loss or maintenance program. Doing resistance training 3 days a week is optimal and 2 a week is adequate. Which do you think is better, lifting heavy or light weights? The answer may surprise you!

By industry standards, lifting heavy weights is the key to optimizing muscle mass and strength. The goal is to lift at about 85% to 95% of your maximum capacity for at least 3 sets of 10 repetitions. Of course, this type of lifting is challenging and gets you far beyond your comfort zone. When you do the last 3 repetitions of the last set you are close to maximal fatigue. This type of demand on your muscles challenges your tendons, ligaments and bones too. The trouble is, muscle will respond faster than tendons and as you load more and more you risk suffering from tendinitis. For older people, lifting heavy weights increases risk of tendon injury as well as being too demanding.
The good news is, recent research shows that using lighter weights can increase muscle size and strength too! You just have to do many more repetitions. In a recent study, men were performing at 30% to 50% of their maximum capacity for up to 25 repetitions, enough to exhaust the muscles. “The results were unequivocal. There were no significant differences between the two groups. All of the men had gained muscle strength and size, and these gains were almost identical, whether they had lifted heavy or light weights.”

“Interestingly, the scientists found no connection between changes in the men’s hormone levels and their gains in strength and muscle size. All of the men had more testosterone and human growth hormone flowing through their bodies after the workouts. But the degree of those changes in hormone levels did not correlate with their gains in strength.”

“Instead, the key to getting stronger for these men, Dr. Phillips and his colleagues decided, was to grow tired. The volunteers in both groups had to attain almost total muscular fatigue in order to increase their muscles’ size and strength.”

This is good news for people who do not like, or are at risk, doing heavy weights. The key is either way, you need to feel like you cannot do one more repetition when you finish!
You can read more in the New York Times article, Lifting Lighter Weights Can Be Just as Effective as Heavy Ones that was published  July 20, 2016.
Lift Weights and Thrive!
Enid Fox

Enid Fox, BA, ACSM Certified Health Fitness Specialist, ACSM/ACS Certified Cancer Exercise Trainer, is a Personal Trainer at BayClubs Courtside.

She can be reached at

  4 comments for “Lighter Weights versus Heavier Weights

Leave a Reply

Your email address will not be published. Required fields are marked *