Keys, iPod, water bottle: Even small objects can weigh a runner down

Minneapolis Star TribuneKeys, iPod, water bottle: Even small objects can weigh a runner downMinneapolis Star TribuneIf you're holding something — it doesn't matter what; it can be a water bottle, an iPod or a set of keys — you create tension and imbalance in your upper body. That, in turn, makes you exert more energy, and the more effort you expend, the faster you ...