Light weights build more muscle

Lads, it may be time to clear out those rusty cast-iron dumbbells from under your bed. Researchers now say that even though lighter weights might not look as impressive, they may help you bulk-up better than heavier ones.

In terms of building muscle mass, more repetitions of light weights has proven to be just as, or potentially more effective than, less repetitions of heavier weights, researchers in Canada have reported.

Nicholas Burd, the researcher who led the study at McMaster University in Ontario, said it's not the size of the weight, but the length of the workout that counts; meaning a low intensity workout for a longer period of time might be more effective.

"Other resistance protocols, beyond the often discussed high-intensity training, can be effective in stimulating a muscle building response that may translate into bigger muscles after resistance training," he said.

Burd explained that lower intensity training sessions involving more repetitions may be more effective because they "sustained the muscle building response for days".

However, to gain the optimal muscle building benefits of using lighter weights, the person must reach their absolute maximum fatigue, which means longer work-outs.

Sydney-based personal trainer and owner of New Outlook Fitness Natalie Carter disagrees that a longer session with lighter weights is more effective.

"In my opinion, to increase muscle size, a heavy lifting protocol is favourable," she says. "As the data suggests, lifting lighter will give you muscle increases, but most gym goers are time poor, therefore a workout with a higher output (heavy lifting combined with low reps) will have you completing a workout quicker and more effectively.

"Starting lighter is always recommend for beginners but eventually you will need to increase weight to see further change in muscle and training load," she added.

Burd's opinion piece entitled Bigger weights may not beget bigger muscles: evidence from acute muscle protein synthetic responses after resistance exercise appears in the June 2012 edition of the journal Applied Physiology, Nutrition, and Metabolism.