Music makes the heart grow fonder and also helps the body get firmer, experts are saying.  Exercising to the proper music can boost your mood, kick your workout up a notch and channel the energy of a younger you, according to Shirley Archer, author and spokeswoman for the American Council on Exercise.   “A number of studies show that music can impact mood, emotions, energy levels, even breathing and heart rates,” Archer adds.  The research comes from music therapy, sports, surgical recovery and gait training studies for people with neurodegenerative issues.   “Music is powerful because it stimulates different neural pathways in the brain and taps powerfully into our emotions and our memories.”   Not only can music help people power through workouts, she said, it can distract them from boredom, fatigue and discomfort.