Improving jump performance, specifically the vertical jump is one of the most common goals for court-based athletes. The desire for an increased vertical jump is not unfounded, as an improved vertical jump will relate to improved performance on the court, through improved ability to rebound or make layups/dunks in basketball, or block shots and contest high balls in netball.
There is no universal blueprint for all athletes to improve jump performance. Identifying a specific athlete’s strength and power profile can help adapt their training to receive the best results. As part of the Vision Athlete Development program, we identify our athlete’s reactive strength index, and conduct numerous other tests to quantify strength and power.
The reactive strength index is a metric that is used to assess the athlete’s potential to produce explosive movements, such as jumping, bounding and sprinting. The score shows how well the athlete can utilise the stretch-shortening cycle mechanism. The stretch-shortening cycle occurs in each muscle during a movement, and is it comprised of three phases. The eccentric phase is the landing or deceleration part of the movement and is used to store potential energy the next phase. The second phase is the amortisation phase, this is the bridge between the eccentric and the concentric portion. An effective amortisation phase means that the potential energy created during the eccentric phase, is effectively turned into kinetic energy. The concentric phase is the rapid shortening of the muscle(s) to produce an explosive movement, and it is a culmination of the stored elastic energy and the strength of the individual muscle fibres.
If an athlete scores a high RSI, but does not have a high vertical jump score, this suggests that the athlete effectively utilises the SSC, but does not have enough relative strength which is decreasing the potential for increased take-off velocity. Therefore, for this athlete to improve their vertical jump score, more time spent on improving lower body strength will be more beneficial than plyometric and ballistic training.
Conversely if an athlete has a low RSI, this suggests that this athletes training should be focused on improving their rate of force development. This can be done by increasing elasticity and rate coding through bodyweight, resisted, and assisted plyometric training, Olympic lifting, ballistic and resistance training. Improved muscle elasticity improves performance through an increased capacity to hold and release energy, and a reduced energy expenditure during high intensity movements, such as a vertical jump. Rate coding refers to the time it takes for electrical impulses from the brain to the muscle to generate and transmitted along a population of neurons. An improved rate coding will result in more muscle recruitment of type IIa and IIb muscle fibres which will improve explosiveness.
Another big component into jump performance is technique! The effectiveness of your jump mechanics can have just as big of an impact as the factors named above. Working on jump technique, off 1 and 2 feet are also a priority for our court-based athletes.
For our athletes, specifically for court-based sports, this is our approach to increasing performance through improved jump performance.