Issues with Plyometric Training
Though plyometric training is a very potent training modality for improving athletic performance, there are several important issues practitioners must fully understand and take into consideration before they attempt to deliver any form of training prescription.
Plyometrics are highly-coordinated and skillful movements
Plyometric activities require athletes to produce high levels of force during very fast movements. They also demand the athletes to produce this force during very short timeframes. Perhaps the best example of this is sprinting. Maximal speed sprinting demands that the athlete moves their body and limbs at the very pinnacle of their ability – making it an extremely fast movement.
Athletes have also been shown to produce ground reaction forces during each foot contact of 3-4 times bodyweight (52, 53). Not only that, but they must apply these huge forces in a GCT of just 80-90 milliseconds (3). So during sprinting, athletes are required to move as quickly as possible, produce forces of over 3-4 times bodyweight, and do so in just 80-90 milliseconds.
As a result, plyometrics are not typically seen as just exercises or drills, but more as complex ‘movement skills’ due to their high-complexity. Understanding this is vital and highlights how highly-coordinated these movements are, and why they require a large amount of attention and coaching if optimal, yet safe, performance gains are to be made.
The intensity of plyometrics is difficult to measure
Arguably, volume of plyometric training is relatively easy to measure and prescribe and is typically done so by counting the number of ground contacts per session, otherwise referred to as simply ‘contacts’. However, measuring and prescribing plyometric intensity is far more complex. To accurately measure plyometric intensity, the following components must be taken into consideration (2):
- Speed of movement
- Amplitude of movement
- Points of contact (i.e. unilateral or bilateral)
- Body mass
- Technical competencies
- Strain yielding competencies
To provide just one example, let’s take a quick look at body mass. If two athletes perform a drop-jump from a 30cm box, but athlete A is 60kg and athlete B is 80kg, then athlete B has to absorb and re-apply more force than athlete A simply because of their weight.
This simple example demonstrates how the intensity of this plyometric activity is different for each of these athletes. Practitioners must ensure they take this information into consideration when planning and prescribing any form of plyometric training.