Why Exercising Muscles Tire When Needed Most

... Fleeing animals, human athletes and non-athletes alike have experienced skeletal muscles giving out during those intense efforts when they are needed most, whether running for survival, the finish line or the bus. While the cause of muscle fatigue has interested to physiologists, engineers and medical experts for more than half a century, the phenomenon remains incompletely understood. A new study from Rice and Harvard universities links failing muscles to the source of the chemical energy utilized to fuel vigorous contractions in the body. ...