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It’s commonly believed that lifting heavy weights is the only way to build muscle, but a Canadian study has busted that myth. Researchers at McMaster University in Hamilton, Ontario, found that doing more repetitions with a lighter weight works just as well-as long as the exercise is done to a point of muscle failure, meaning the muscle can’t do another repetition with proper form. In the study, 15-20 repetitions with a lighter weight were just as effective as 8-12 repetitions with a heavier one. Researchers believe the lighter-weight method has greater appeal to novice exercisers, rather than to elite athletes.