Maria has been working out using free weights for a long time in an attempt to become stronger. Which muscles have MOST likely benefitted from her efforts?

Free-weight exercises make muscles contract to move and stabilize the body. These are skeletal muscles, which are attached to bones and can be controlled voluntarily, so they are the muscles most likely to have become stronger. Smooth muscles and digestive muscles work inside organs, while “involuntary muscles” are not the main target of weight training.

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