Question: Bill and Bob were two brothers. they were both into physical exercise, but Bill chose weight lifting, and Bob running.  Given the paragraph above, please answer correctly the following question:   Which brother had smaller muscles?  Hint: In exercises such as weight lifting, skeletal muscle contracts against a resisting force (see Figure below ). Using skeletal muscle in this way increases its size and strength. In exercises such as running, the cardiac muscle contracts faster and the heart pumps more blood. Using cardiac muscle in this way increases its strength and efficiency. Continued exercise is necessary to maintain bigger, stronger muscles. If you don’t use a muscle, it will get smaller and weaker—so use it or lose it.
Answer:
Bob