Speed Development: Stretch-Shortening-Contraction, Sprint Bounding and Testing
Bounding is an important component of Speed Development. Properly instructed and applied to a speed training program can improve the Stretch-Shortening-Contraction (SSC), and benefits the speed and acceleration phases of sprinting. Kenta Bell has put together a great How to Teaching Video on the proper technique of Bounding.
Practicing the correct sprint bounding technique will improve your sprinting efficiency when properly practiced.
Check out the Video here:
VIDEO: How to Teach Bounding (in 4 Easy Steps)
Testing Sprint Bounding Performance
Testing Sprint Bounding Performance can be used as a baseline for your speed training program. The classic Sprint Bounding Index(SBI) test will measure the Stretch-Shortening-Contraction in a 30 meter distance.
The SBI Testing method is described below:
Prior to the testing a 10-15 minute warm-up period of light running and striders is performed.
- Measure off a 30-meter distance on a field or track.
- Use a 10-meter Fly Zone marked off before the start of the 30-meters.
- Take off one foot at the start of the 30-meter distance.
- Bound R-L-R-L-R...(or whatever foot your start with, one foot to next) over the 30-meter distance.
- Count number of contacts you make, beginning with first touch within the 30-meter zone to the end.
- Time the duration with stop watch from foot contact at Start(Take off) to end of 30-meter zone.
- The SBI is measured as Time(seconds:tenths) x Number of Steps to complete 30-meters.
Example: 4.5 secs x 13 = 58.5(SBI)
As you train and re-test, the SBI will decrease with improvement.
Bounding can also be tested for distance using 3 different tests that have been correlated to 100 meter time. Bounding is a right-left-right-left sequence measuring the horizontal power of the athlete. There are a few tests that will measure athlete power:
- Vertical Jump
- Horizontal-Standing Long Jump(off both legs)
- 3-Bounds
- 5-bounds
- 10-bounds
- 3-hop
- Performed on one leg for distance( Example: R-R-R) from a single leg, standing still start.
- The test is completed with the 3rd contact into the sand pit.
- This is a good test for comparing right vs. left leg power measures and is used frequently as a return to activity functional test after lower leg injury/surgery.
Stretch Shortening Contraction Training
Effective training to improve SSC requires specific exercises to increase the activation of muscles used in the transition of an eccentric contraction (lengthening) to a concentric contraction (shortening). This rapid transition creates a more forceful contraction, and production of explosive power. This translates into increased power production, and ultimately, speed. In the case of the sprinter, this power production must take place in the horizontal direction greater than the vertical direction (Ex. Vertical Jump).Requirements for increasing the explosive power are:
- Increased eccentric strength
- Increased neuromuscular efficiency
- Optimal Stabilization Strength: Core musculature and joints(in all planes of movement).
To achieve maximal explosive power in your training program careful progression of loads and volume(repetition) must be practiced. For the young athlete this progression should be slow and with lower volumes and intensity(weight). This is practiced to achieve maximal training benefit without injury to muscle-tendons and joint structures.
Speed development can be maximized with resistive training, plyometrics/bounding, and core strengthening activities.
Examples of Resistive Training include:
Back squats(1/2 and 1/4 squats)
Bent leg dead lifts(Romanian)
Bulgarian Squats
Examples of Plyometric and Speed Drills
In the next episode we will discuss Core Stabilization Exercise for the Athlete implementing a speed training program.