For building muscle it is not necessary to bother lifting extreme weight. Even light weights will do the job, said us scientists.
They conducted a 12-week experiment, which involved two groups of men. Both groups trained until until you feel muscle fatigue.
When the first group used a fairly large weight (up to 90% of maximum repetitions in the range from 8 to 12 times). And the second group worked with moderate weights (up to 50% of the allowable load and 20-25 reps).
At the end of the experiment, the researchers assessed the condition of the muscle tissue of volunteers. It turned out that a number of indicators (increase in mass and size of muscle fibers) results in the groups was similar.