The secret to mighty muscles isn’t necessarily lifting heavy

Arnold Schwarzenegger making muscles in 1977 docudrama Pumping Iron

Think muscles and you might think Arnie-style barbells stuffed with immense weight plates at either end, bulging veins and the occasional grunt.

In fact, it’s long been believed that to grow muscles, you need to lift weights that are as heavy as possible. But while this is indeed a proven strategy – it’s not the only one.

Lifting lighter weights has also been shown to stimulate muscle growth.


The proof?

Last year, a study of 18 men over 10 weeks by McMaster University looked at this exact issue. It determined that a lower load lifted to failure resulted in similar hypertrophy as a heavy load lifted to failure.


How can that be?

Heavier loads activate a greater number of higher threshold but “faster-to-fatigue” muscle fibres. That means the muscles get tired before they get overloaded, diminishing muscle growth potential.

Meanwhile, lighter loads recruit the “slower-to-fatigue” muscles because the initial demand is less. If worked to failure, that means more muscle fibres are overloaded.



Fortunately, the best plan of action is pretty simple – to ensure your training regime is varied.

Aim to mix up repetitions either on separate days or within the same session.

Do as many reps as you can – i.e. reach the point of fatigue – in order to ensure better overload.

Add resistance as sets become easier – even if you’re going light, stronger muscles can handle more weight.

You may be sceptical, but give it a go. Science has shown you can grow your muscles with higher reps on a lower weight.


Have you seen great results training with a lighter load?



Posted by

Journo turned fitness professional, passionate about helping people to live a healthier and happier life! A long way from London, I now call Sydney home.

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