Considerations for ballistic training
Though ballistic training is a very effective training method for improving athleticism and sports performance, there are several important issues practitioners must take into consideration before prescribing this modality to athletes.
The resistance used for ballistic training causes specific changes to the force-velocity relationship, which then changes the degree to which power output is improved [9, 16]. Several studies have asserted that training with the load that maximises power output is more effective at improving power production and athletic performance than either lighter or heavier loading conditions [2, 25, 26, 41]. This has, therefore, been termed the “optimal load”.
Despite several studies demonstrating optimal loads, however, a meta-analysis of the literature proves inconclusive. Depending on the exercise performed and measurement method, as well as the gender, previous strength level, and training history of the subjects, loads ranging from 0-80% 1-RM have been identified as “optimal” . Furthermore, in a study by Cronin et al., , loads ranging from 40-70% 1-RM were found to be similarly effective.
Many sports require powerful actions with a range of loads. For example, sprint cyclists must overcome heavy loads as they attempt to drive the bike off the start line as quickly as possible, but, once the bike is up to speed, the resistances are low . Similarly, rugby union players may have to exert large forces quickly during a scrummage  but may have to also produce power at low loads when performing activities such as sprinting, passing, or kicking . For ballistic training then, there is perhaps no “optimal” intensity or resistance.
Both heavy and light intensities have applications in the training of muscular power ; therefore, a variety of loads should be used in an organised fashion to elicit superior power outputs across the force-velocity curve.
Given that ballistic training concentrates on the velocity of the load, it is the intent to lift the load as fast as possible that seems to be the mechanism by which neurological and physiological adaptations occur. Therefore, heavy-resistances are effective at increasing power if the athlete attempts to move the load as quickly as possible, even if the actual movement speed is slow .
For example, the ballistic actions of weightlifting (e.g. Snatch, Clean & Jerk, etc.), which requires a high level of intent to produce the high force and RFD magnitudes needed to lift the weight, has been shown to recruit larger motor-units than endurance-based tasks which require lower-levels of intent ; thus raising the potential for positive power adaptations .
The problem then is how to measure intent. One method that has increased in popularity in recent years is velocity-based training (VBT), whereby a variety of parameters, including peak and mean velocity can be measured . The real-time feedback available with many VBT systems appeals to the intrinsic competitiveness of the majority of athletes, who inherently want to be the fastest and most explosive in their training group.
Another technique ensuring high-levels of intent, even at submaximal loads, is the use of velocity loss as a method of performance regulation . For example, an athlete performs jump squats with an initial velocity of 1.0 m/s and must continue to perform repetitions until the velocity falls below 0.9 m/s (i.e. a 10% velocity loss). Modest velocity losses (e.g. 10-15%) are recommended during ballistic training to ensure that the exercises stress the central nervous system and minimise peripheral fatigue .
Although the use of ballistic training methods for improving the athletic capabilities of athletes is highly effective, the high eccentric forces experienced by the athlete when landing from a jump or catching a falling weight may pose a safety concern, especially if larger loads are being used.
Coaches are encouraged to remember that ballistic training is an advanced method of training and the most effective method of developing power in novice athletes is to first develop high-levels of strength [12, 33, 43, 44].
Once this has been achieved, practitioners should plan and periodise preparatory phases for ballistic training, ensuring that it progresses gradually from unloaded (e.g. bodyweight or less) to loaded conditions .
In addition, the use of some of the VBT methods mentioned above ensures that peripheral fatigue is kept to a minimum , thereby reducing the likelihood of an athlete losing control of the weight. Furthermore, specialised training equipment, such as ballistic braking systems , can help reduce the eccentric resistance.