Question

as soon as you were lifting a box someone places extra weight on top of it for your muscles to continue contracting and lifting the box the muscle must _____

Answer 1

As soon as you were lifting a box and someone places extra weight on top of it, for your muscles to continue contracting and lifting the box, the muscle must **generate more tension**. This additional tension allows the muscle fibers to overcome the increased load and continue the contraction necessary to lift the box. The recruitment of more motor units or an increase in the frequency of muscle fiber contractions may also occur to achieve this greater tension.