When it comes to the subject of how to train athletes, there is no shortage of strength and conditioning experts who champion their methods. Some believe in functional training, some powerlifting or Olympic lifting, some strongman training, and of course there are those who promote high-endurance boot camp systems. Whatever system you chose, or combination of systems, you should consider addressing the issue of elastic strength.
Elastic strength can be thought of as the building blocks of dynamic movement. Most athletic activities are performed dynamically, involving movements that create, store, and release energy. This energy enables the athlete to move faster and with more power. Elastic strength is why you can jump higher if you rapidly bend and straighten your knees; rather than bending your knees, pausing for several seconds, and then jumping.
One of the basic qualities of athletic fitness is the ability to run fast. Track coaches will tell you that the major variables that determine how fast you run are stride frequency, stride length, and ground contact time. Stride frequency is how quickly you change your support from one foot to the other, stride length is how much distance you cover with each running stride, and ground contact time is how long your feet are in contact with the ground.
Because stride frequency is not as trainable as stride length and ground contact time, most coaches will not spend much time on it. It’s not that stride frequency cannot be improved, but that coaches will get more “bang for their buck” by focusing on these other sprinting components. Let’s start by taking a look at stride length.
In 1991 Carl Lewis ran the 100 meters in 9.86 seconds, a world record, and he did it in 43 steps. In the 2008 Usain Bolt completed the 100 meters in 41.4 steps and shattered the world record with a time of 9.69 seconds, and the following year covered that distance in 40.92 steps and exceeded his world record with a time of 9.58 seconds. Thus, all things being equal, if you cover more ground with less steps, you run faster.
What primarily determines stride length is how much force an athlete puts into the ground. Strength is key here. In 2005, a paper was published in The Journal of Experimental Biology that looked at the physical qualities of athletes who competed in eight running events in track and field (100 meters to 10,000 meters) from 1990 to 2003. The researchers found that those athletes who competed in the shorter running events, from 100m to 400m, carried the most muscle mass. But it’s not just muscles that are involved in applying force, the tendons also play a role.
Tendons shouldn’t be thought of as rigid cables, but as elastic springs that store and release energy. When a sprinter’s foot strikes the ground energy is created, stored in the tendons, and then released to help with propulsion. In effect, the entire leg becomes a biological spring that helps produce a more powerful movement.
The next speed factor to look at is ground contact time. Research on sprinters found that there was a significant difference in ground contact time between poor and good sprinters. In addition to taking additional time to complete a step, spending too much time on the ground can cause the front foot to be placed ahead of the center of gravity. In effect, this reduces horizontal force. As for the numbers, one study found that good female sprinters spend .083 seconds on the ground compared to .093 seconds for poor sprinters, and good male sprinters spent .087 seconds on the ground compared to .101 seconds for poor sprinters.
In the weight room, among the most dynamic movements performed are the Olympic lifts, and one reason they can be performed so quickly is due to the use of the body’s elastic qualities. When lifters pull the barbell off the floor, after the bar passes the knees the hamstrings will react to the powerful contraction of the quadriceps by flexing the knees. The faster the movement off the floor, the faster this stretch-reflex of the hamstrings. Thus, rather than using a slow, deliberate pull at the start of a lift and then exploding during the second part of the movement, lifters should pull the bar as fast off the floor as good technique allows to create a more powerful stretch reflex.
With that background, how does an athletic improve elastic strength? Here are three guidelines.
1. Work the muscles through a full range of motion. It’s the opinion of many Russian sports scientists that if you work the muscles through a partial range, such as a parallel squat, you will reduce the tendon’s elasticity and ability to function. If you cannot perform full squats, consider including exercises such as lunges and split squats to ensure healthy tendons.
2. Perform resistance training movements that involve a powerful stretch reflex. Exercises such as the Olympic lifting movements, barbell and hex bar squat jumps, medicine ball throws, and even some kettlebell exercises fall into this category.
3. Perform plyometric exercises that decrease the time between the eccentric (joint flexing) and concentric (joint extending) contractions. Plyometric depth jumps, skipping, hopping and other such dynamic movements are examples of such activities. Two classic, practical books on how to perform these types of exercises and design workouts for them are High-Powered Plyometrics by Radcliffe and Farentinos, and Plyometrics by Chu and Myer.
The preponderance of research and opinions about how to train athletes can be overwhelming. If your focus is on achieving superior athletic performance, design your workouts to address the concept of elastic strength.