There are two phases of muscle contraction that occur when you lift a weight. The first is the concentric contraction, where the muscle shortens as the weight is lifted. This is often called the “positive” contraction. The second phase is the eccentric contraction, or “negative.” This is when the muscle lengthens as it produces the force needed to resist the pull of gravity or the momentum of the movement. Research has shown that the negative phase of the contraction generates 20 to 40% more force than the positive phase. So, be sure to use slow and controlled movements when you both raise and lower a weight to get the maximum benefit of the exercise.
(Source: Sternlicht, E., Feineman N. “Fuel Up: Using the Principles of Sports Nutrition to Perform like a Pro.” Berkley Publishing Group, New York: 2001. pp. 133)
Quote of the Day
“I am careful not to confuse excellence with perfection. Excellence, I can reach for; perfection is God’s business.” – Michael J. Fox