E-Mail Exercising regularly is one of the best defences against metabolic diseases, such as obesity and diabetes - but why? It's a question that scientists are still struggling to answer. While exercising changes the molecular behaviour of muscles, it's not well understood how these molecular changes improve metabolic health. Scientists at the University of Copenhagen have now developed a new technology that allows researchers to study muscle biology on a more detailed level - and hopefully find some new answers. They extracted 'fast' and 'slow' twitch muscle fibers from freeze-dried muscle samples that were taken before and after 12 weeks of cycling exercise training. Their comprehensive analysis of the protein expression of the fibers provides new evidence that the fiber types respond differently to exercise training.