" He changed and worked out with weights. Throughout his adult life, Adam had cycled through a potpourri of workout programs—yoga (not flexible), Pilates (confused), boot camp (why not just join the military?), Zumba (don’t ask), aquatics (near drown), spin (sore butt)—but in the end, he always returned to simple weights. Some days he loved the strain on his muscles and couldn’t imagine not doing it. Other days he dreaded every moment, and the only thing he wanted to lift was the postworkout peanut butter protein shake to his lips. He "

― Harlan Coben , The Stranger