The Theory Behind Lycra® Power™
Working muscles contract over and over again, and as anyone who exercises knows, these repeated contractions can lead to post-exercise soreness. But there are two types of contractions, and their effects on the muscles are very different.
Eccentric contractions occur when the muscle lengthens under tension to decelerate the body. For example, when a runner's foot strikes the ground the quad muscle (on the front of the thigh) must contract to prevent the leg from collapsing.
Contrast this with a concentric contraction, which involves contraction of a muscle while it shortens. An example would be leg extensions on a nautilus machine in the gym. The quad contracts and shortens to extend the leg and straighten the knee. Concentric type exercises, such as weight training, are far more common and widely practiced than eccentric exercises, such as plyometrics. However, it is the eccentric phase of the running stride that wears out the quads during a race. This is primarily due to two reasons. One, eccentric contractions are harder on the body than concentric contractions. And two, specific eccentric exercises are not a part of most runner's training programs.
Obviously, targeting eccentric contractions with specific training such as plyometrics will help prevent related muscle soreness. However, recent advances in fabric design may also enhance recovery as well as improve performance. A series of findings from a research program conducted at The Penn State Center for Sports Medicine show a direct link between wearing compressive sports apparel and an athlete's performance. Dr. William Kraemer, a distinguished sports medicine expert, conducted the research over a five-year period in collaboration with DuPont, Wilmington, DE. The DuPont fabric being tested was their stretch fabric called LYCRA® POWER™.
LYCRA® POWER™ garments impact performance levels by reducing muscle fatigue and improving proprioception. The research showed that all types of fatigue (strength, endurance, and power) can be significantly reduced by wearing LYCRA® POWER™ apparel. The findings showed that an athlete's force and power production increased by an average of 12% and that 73% of the athletes tested increased the accuracy of their movements or body positioning.
Of interest to triathletes would be the results from their tests on endurance. Endurance fatigue was produced by a run at 70% maximum heart rate on a treadmill set at 2% incline. The effects of the LYCRA® POWER™ garment were determined by comparing the results of the laboratory jump analysis of ten consecutive maximal jumps on a force platform before and after the run. In both the trained and the untrained subject,s there was significantly greater performance in those wearing the LYCRA® POWER™ apparel than those who did not.
The research appears to prove that compressive fabrics improve performance by:
- Reducing muscle fatigue
- Helping maintain energy levels
- Improving proprioception
- Improving center of motion
- Increasing efficiency of movement
- Providing heightened responsiveness
- Improving force and power production
- Reducing muscle vibration
Simply put, by compressing the muscles with a suitable fabric, you can decrease the small vibrations that occur during contraction. These repeated vibrations can lead to fatigue, soreness and loss of body position.
There are a couple interesting points regarding the use of Lycra Power™ fabric in clothing that Dupont expects it's users to follow. To obtain Lycra Power™ certification, garments must follow certain guidelines. These guidelines involve materials, construction and garment usage.
1. Garment must use fabric which has been certified Lycra Power™.
2. Fabric must be cut and sewn with high power direction perpendicular to the muscle group.
3. The primary body of the garment must use Lycra Power™ fabrics (exclusive of trims and inserts).
4. The benefits of Lycra Power™ are achieved when a muscle group is covered.
5. To provide adequate comfort, fit and durability only Lycra® is used in the waistband and trims. Generic elastane or rubber is not allowed.
6. Seams and waistbands must stretch with the garment, matching the fabric's extensibility. Seams or waistbands should not block elongation of the fabric, which would prevent proprioceptive effects.
While not specifically stated anywhere, these guidelines tie into the research that was done and help insure that a manufacturer who utilizes Lycra Power™ will obtain the full effects that Dupont advertises.
The stuff stays put. Because the material is designed to fit tightly, there's a lot less creeping and sliding around of material once you have it on. In fact, the suits that used Lycra Power in the legs don't even use gripper elastics.
You can feel the difference in the fabric. It's definitely tighter around the legs, but in a good, secure way. You have the sense that it's going to help your legs spring back into position once they begin to move.
Article by Mark Steckel