article_snippet: Electrical stimulation is then used .
article_snippet: to make the muscle strips contract and 'bulk up' - the laboratory .
article_snippet: equivalent of working out in a gym.
article_snippet: other cell - are stripped from cow muscle, which is taken during a . harmless biopsy.
article_snippet: This is then bulked up through the laboratory equivalent of .
article_snippet: exercise - it is anchored to Velcro and stretched.