If muscle biopsies were taken from the legs of a world class Marathon runner and a typical couch potato, which would you expect to have a higher density of mitochondria. Why? How would the density of mitochondria in a muscle biopsy from the biceps of a weight lifter compare with those of the runner and the couch potato?© BrainMass Inc. brainmass.com October 9, 2019, 7:11 pm ad1c9bdddf
Comparing muscle biopsies from a marathon runner and typical couch potato would reveal a higher density of mitochondria in the skeletal muscle fibres of the marathon runner. The predominant skeletal muscle fibre would be Type 1 or slow oxidative fibres, which have a slow contraction speed and a low myosin ATPase activity. These cells are specialized for steady, continuous activity and are highly resistant to fatigue. These ...