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Fitness & Health

24th Jul 2019

Light weights as good as heavy lifting for building muscle and strength

You don't need to set a new bench press record every time you hit the gym. Light weights are proven to build as much muscle as heavy lifting

Alex Roberts

You don’t need to set a new bench press record every time you hit the gym

Light weights are as good as heavy ones for building muscle mass and strength, according to research.

Muscle growth is dependent on a number of factors – particularly volume and training to the point of fatigue

It is overall volume and muscle fatigue which explain why light weights are effective, says a study published in the Journal of Applied Physiology.

As part of the study, scientists took a group of men and analysed how their leg muscles responded to different kinds of strength training over a 10-week period.

Each person was tested to see how much they could lift for a one rep max (1RM) on the quad extension.

Why light weights work so well

The group was then divided in three for the following 10 weeks. When working out, each of the three groups were asked to train slightly differently:

  • One group performed a single set of quad extensions with 80% of their maximum
  • The second group performed three sets with 80% of their max
  • A third group performed three sets with 30% of their max

Subjects followed this system three times a week. On each set, they aimed to complete as many reps as possible.

After the 10 weeks were up, scientists performed an MRI scan on all the participants to measure muscle growth.

Both of the groups who performed three sets experienced the same amount of muscle growth. This is surprising, considering the light weights group was only lifting with 30% of their maximum.

You may have assumed that the group lifting much heavier weights would experience greater muscle gain, but that wasn’t the case. They gained marginally more strength, but the group lifting light still made big improvements in that area.

This proves you should probably be training with a variety of loads, sets and rep ranges in order to maximise your results from weight lifting.

Those who performed one single set gained half as much muscle as the groups performing three. Weight lifted isn’t the most important factor, overall volume is – hence why three sets seems preferable to one.

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