Rod Lindsell is a Strength and Conditioning Coach at the Australian Institute of Sport (AIS). He is responsible for the strength and conditioning of the AIS Men’s Basketball Program of which 11 scholarship holders where part of the Australian U19 Men’s Team, who won the recent FIBA U19 World Championships. He is a specialist in the area of conditioning for field and court based sports.
High level muscular power is a physiological characteristic that coaches want their athletes to possess. Muscular power is the product of the force and velocity of a muscular contraction and can be expressed as the rate of doing muscular work.
High levels of muscular power, when coupled with the right technical skill, has the potential to facilitate superior athleticism, in the form of speed, agility and jumping ability.
Muscular power is largely dictated by an individuals composition of muscle fibre types and their neuromuscular characteristics.
This article will examine these factors and the effect of different resistance training regimes on this desirable athletic quality.
MUSCLE FIBRE TYPES
Muscle fiber types can be classified into 2 broad groups, Type I (Slow Twitch) and Type II (Fast Twitch).
In general Type I fibers have preferences to work aerobically during low-moderate intensity activities over extended periods.
These fibers are most suited to endurance activities and are the preferred muscle fibre type of marathon runners and endurance cyclists.
Type II fibers have the ability to shorten rapidly to produce force quickly and at high power outputs.
They are best suited to high intensity, short duration work intervals.
These characteristics make Type II fibers best suited to power orientated activities such as jumping and sprinting.
Skeletal muscle is composed of both Type I and Type II muscle fibers.
The percentage of each fibre type is largely genetically determined and not significantly effected by training.
When the neuromuscular (nerve and muscular) physiology and structures are inspected the major factors that limit muscular power generation can be grouped into neural and mechanical factors.
The neural factors relate to the ability to recruit muscles and the individual muscle fibers. Timely and concise recruitment of muscle fibers will result in the summation of force and potentially more rapid and forceful contractions.
The mechanical factors relate to the actual contractile units of the muscle which are responsible for force production. The greater the number of cross bridges lined up in parallel within a muscle fibre, the greater the cross sectional area of that fibre and the greater its ability to produce force.
By understanding both the neural and mechanical factors involved in muscle contraction a coach can target training phases toward optimising these traits.
Below is a summary of how different training types influence muscular power.
GENERAL STRENGTH TRAINING
General strength training can be described as moderate intensity (615RM loads), moderate volume (6-12 sets per large muscle group), and slow speed resistance training.
Specific adaptations induced by this type of training include an increase in contractile units within the muscle fiber, which is associated with an increase in the cross sectional area of the muscle (hypertrophy). Significant adaptations also occur in the nervous system, primarily changes in the intra and intermuscular recruitment patterns.
These mechanical and neural adaptations account for the improved ability of an individual to produce force following a phase of general strength training.
The greatest improvements in force production (strength) are seen at slow contraction velocities similar to those used in training. The improved force production capacity is often reflected across the spectrum of contraction velocities in untrained individuals.
This would account for improvements in vertical jump seen in response to a period of general strength training.
MAXIMAL STRENGTH TRAINING
Maximal Strength Training (MST) is high intensity, low volume, slow speed resistance training.
Loads of 1-5RM are typically used, with more than 10 sets performed per muscle group. MST is usually performed 2-5 times a week on the same muscle groups with the goal of lifting maximal loads.
Adaptations to MST are both neural and muscular. Intense loads facilitate the recruitment of Type II (fast twitch) fibers who are integral players in power performance. Selective hypertrophy is expected to occur in these fibers, along with intra and intermuscular changes in motor unit recruitment patterns.
The outcome of a phase of maximal strength training for a moderately trained athlete is likely to be an increase in force production capacity at velocities similar to those used during training.
Like general strength training some of these gains may be reflected across the velocity spectrum, but this appears to be dependent on the training status of the individual.
If maximal strength training does produce improvements in power performance it would be most likely due to adaptations of the Type II motor units and order of motor unit recruitment of these fibers.
The current research literature supports a strong correlation between maximal strength and power in subjects with a variety of training histories.
EXPLOSIVE OR BALLISTIC RESISTANCE TRAINING
Olympic style lifts and high-speed derivatives of traditional exercises are useful training methods when looking to enhance an athletes muscular power characteristics. These types of training are characterized by exercises that demand the individual perform large amounts of mechanical work in short periods of time.
These exercises aim to optimise the relationship between force production and contraction velocity to achieve high power outputs. Power snatches, power cleans, squat jumps and bench throws are examples of activities that fit into this category.
These exercises require the neuromuscular system to recruit large numbers of muscle fibers quickly and efficiently to satisfactorily complete the task. Specific adaptations to this type of training relate mainly to improvements in intramuscular recruitment and selective hypertrophy of Type II muscle fibers. These types of training have been reported to result in the greatest gains in peak power output (high speed force production) when compared to general strength and plyometric training.
The optimal loading for these exercises is often a contentious issue. To achieve maximal power outputs in squat jumps and bench throws the optimal loading is likely to be between 30% and 60% of 1RM.
In Olympic style lifts optimal load is likely to be the within approximately 10% of a 1RM load. The exact percentage for any loading will depend heavily on the exercise being utilised, sets and repetitions prescribed and the training history of the individual.
Plyometric training involves maximal velocity movements, usually against the resistance of body weight and gravity that may or may not involve a rapid pre-stretching of the muscle. Plyometric training helps train the individual to apply and absorb force rapidly and thus specifically develops the force application capacity of the neuromuscular system at high velocities.
Adaptations to plyometric training are predominantly neural with negligible changes to the mechanical structure of the muscle’s contractile units.
All aspects of intramuscular recruitment have been shown to adapt favourably to plyometric training in moderately resistance trained individuals.
Plyometric exercises such as bounding, hopping and jumping are among the most specific types of resistance training exercises for basketball.
These types of exercises provide an excellent stimulus to improve intra and intermuscular coordination at contraction velocities similar to what is required during a game of basketball.
Developing muscular power for basketball requires a strategic approach. This approach must take into account the training status and history of the individual.
Over a period of time training may be general and specific in nature but each training intervention should be targeted toward achieving specific neuromuscular adaptation(s).
To maximize power performance training should expose the athlete to an array of training stimuli which considers the multi-faceted nature of power development and how it pertains to the individual.
Finally, strength and power characteristics developed in the weight room need to be transferred onto the basketball court with an emphasis on specific skill acquisition, during practice and conditioning activities.