Muscular Strength and Power Training
Muscular strength is commonly defined as the ability of muscles to generate maximal force and is often expressed in terms of 1 RM or one repetition maximum. It should be noted that muscles are able to demonstrate maximal force production in a variety of different situations. These include concentric, eccentric and isometric contractions, as well as any variety of movement speed velocities for the isotonic actions.

Development of muscular strength can be of benefit for a wide range of athletic endeavours as well as many everyday situations. Competitive powerlifting (1RM squat, deadlift and bench press) is perhaps the ultimate expression of pure strength in a competitive context. Lifting heavy objects from the floor and placing them on a shelf may be an example of an everyday situation where a reasonable degree of functional strength is required.

Power however, is also a key component of neuromuscular conditioning. Power is determined by the rate at which the body can generate force.
Power can be defined as:

Power =

Force x Distance Time

Power can be considered as the amount of work done divided by the time taken to do it. More simply, power is the 'rate of doing work.'

Uses of power in Everyday Life
Mention power in the gym environment and people will naturally think of elite athletes participating in sports and events such as sprinting, jumping and Olympic weightlifting (clean and jerk, snatch). Because of the perception that power is for elite athletes only, many individuals never even consider power training. These widely held beliefs about power and power training are unfortunate as they cause many individuals to miss out on a valuable and enjoyable area of resistance training.

All individuals should be able to build towards the inclusion of power phases in their long term training plan. It is important to note that power training for the general public is very different from the workouts of elite power athletes. Elite athletes are able to tolerate much higher training volumes, intensities and frequencies, as well as having a much more task specific focus to their training. Power training for the average individual should prepare the individual to perform daily tasks with ease, as well as providing them with something different to try when they head to the gym for their daily workouts.

Although most individuals will never be required to perform a long jump, throw a javelin or complete a competitive clean and jerk, everybody will perform tasks on a daily basis that require some degree of power. For an individual to run up a flight of stairs they are required to propel their body mass forward and up against gravity. For the individual to accelerate their mass and become 'airborne' for a fraction of a second between steps, force must be produced at a significant rate within the muscles. This rapid force development demonstrates the application of power to an everyday task.

Strength and Power for all
It is evident then that the majority of people may benefit from periodically being exposed to strength and power exercises in their training. These exercises modalities are not solely the preserve of the elite sports man or woman but make up two of the components of fitness required for optimal health, fitness and function.

Strength and Power:
Contraindications
Whilst strength and power training is suitable for the majority of the population, some special care groups should not perform this kind of work. Individuals suffering from the following conditions should be excluded from strength and power work:

	Hypertensive (implications of the use of valsalva manoeuvre)
	Osteoarthritis / Rheumatoid arthritis
	Severe Osteoporosis
	Obesity

Training for Strength
Following the principles of exercise specificity, in order for an individual to get stronger they need to lift progressively heavier loads over time.

Intensity, Reps and Sets:
The type of training required to develop muscular strength is characterised by maximal or near maximal training intensities. An understanding of the term intensity is important here, as it will ensure that programmes are developed appropriately for your requirements.

The guidelines for strength training is to perform high intensity sets, performed at 85% or more of 1 RM. It is important to remember that this is a general guideline only. It should be noted that there are a number of acute variables that can be manipulated in order to provide the body with progressive, novel stimulus over time, while continuing to adhere to the general recommendations for strength training.

Guidelines for Strength Training

Characteristic: Strength: Intensity High Load as % of 1RM > 85% Reps 1 - 5 Recovery between sets 3 - 5 minutes Sets per exercise 2 - 6 Frequency per muscle group 1 - 2 times per week

Exercise selection:
Exercise selection will significantly influence the results experienced by the individuals participating in strength and power training programmes. The majority of the exercises chosen will be compound, multi-joint exercises. This type of exercise utilises multiple large muscle groups and requires the recruitment of a high number of fast twitch motor units when performed at high intensities. The exercises that will have the greatest strength developing effects are those that stress the largest muscle groups i.e. the musculature of the upper legs, gluteals and back. Each session should focus on one to three key lifts. Many power-lifters workouts consist of one key lift (squat, deadlift or bench press) followed by a small amount of work on assistance exercise.

Isolation or single-joint exercises are of less value to the individual training for strength. This is because most feats of strength require a high degree of intermuscular co-ordination, with the load being distributed across a number of muscles and joints. Isolation muscles (and joints) may not automatically lead to increased force production when those muscles are asked to integrate with other areas of the body during a dynamic movement task. When training to develop muscular strength it is more appropriate to overload the movement pattern as opposed to individually fatiguing the individual muscles involved in that movement. Zatsiorsky (1995) suggests that isolation exercises should only be used as a supplement to the main training programme when focusing on strength.

Programming for strength:
When planning to train for strength over a period of time, we can take the general repetition guideline (1-5 reps per set) and split it in to two further subsections. We shall plan a basic strength phase consisting of sets of 4-5 repetitions, followed by more intensive maximal strength phase of 1-3 repetitions per set.

The basic strength phase will provide you with an introduction to the strength training intensity and volume, without requiring the maximal intensity effort involved in 1RM attempts. This way, I could utilise the principles of periodisation by logically applying increments in intensity to your strength training sessions.

It highly recommended that the individual has spent time progressively moving through the stages of resistance training prior to attempting a basic strength phase.

Training with endurance and hypertrophy exercise intensities prior to performing strength work should ensure that the individual is able to safely tolerate the load and intensity required to obtain the benefits of the strength phase of training. Remember that a brief 'strength for all' training phase can be utilised if necessary to bridge the gap between hypertrophy and strength work.

Progressing to maximal Strength:
Not all individuals will need to progress to a maximal strength phase in their training. This type of training requires maximal/near maximal loading and carries a high risk of musculoskeletal injury.

Maximal strength training is only suitable for clients involved in sporting activities where either maximal loads are handled (e.g. weight lifting) or where high degree of strength are expressed (e.g. rugby).

For the majority of the general training population, maximal training presents too high a risk of sustaining serious injury.

Before placing an individual on a maximal strength programme, I shall consider whether the potential benefit of this type of training exceed the potential risk. If the risk outweighs the benefit, then maximal strength training is probably an unnecessary phase of raining for the individual in question and strength for all or basic strength parameter will yield sufficient results at a much lower risk.

Progressing into Power
Power, as discussed previously, is strength expressed at speed. The main difference between the executions of strength versus power movements is the intent to move quickly.

They key difference between strength and power training is speed of movement, or the intent of the speed of movement used to perform the exercise. Power training requires the individual to attempt to move the weight or load as quickly as possible. If the load is great then the actual movement speed may not be particularly impressive, however the neuromuscular system will adapt positively to the intended movement speed and increase muscular power.

If the load is relatively low the individual will be able to accelerate through the range of movement easily and the movement speed will be significant. Subsequently, the body will adapt and movement velocity will increase. On the other hand, training with maximum loads will increase maximum force output without necessarily increasing velocity (especially if a large degree of strength has already been gained). Ideally, for power training the participant should be able to release the load (throw it), or leave contact with the ground, as in jumping, hopping and bounding drills. This practice allows the participant to accelerate throughout the entire movement, thus maximising power. Maximal power occurs around 30% of maximal load and two-third of maximal velocity.

Holding on to the load my not bring about optimal gains in power. The vast majority of free weight exercises do not allow the individual to release the weight. This inevitably encourages the neuromuscular system to learn to decelerate the load towards the end of the range of movement. This may limit power transfer into the movement. Traditional free weight exercises definitely have a place in build up to power training as they promote enhanced force development, however dedicated power exercises will push the individual on to new levels of performance.

Power Programme Design
Basic Power training principles:
The following principles will be applied to all power type exercises to ensure that maximal benefit can be derived from this type of training. The following principles shall be applied to all power training modalities:

	Employ a specific graduated warm up with includes exercise rehearsals
	Power movements should only be performed using perfect technique
	Movements should be performed with intent of speed (EXPLODE!)
	Deceleration of training implemented at end range of movement is to be avoided
	Sets typically last under 10 seconds and should certainly last no longer than 15 seconds with no drop off in performance
	Recovery should be full or close to full (3 minutes +)
	Quality of exercise execution should be emphasize over quantity of volume performed

Designing Power Workouts
Exercise Selection:
When constructing workouts to enhance muscular power, exercises that are specific to the objective should be selected. This means that the exercises that will be selected for you will allow significant acceleration of the load. The ideal exercises that shall be included will allow the individual to leave the floor or release (throw) an external load. Examples of such exercises would include:

	Jumping
	Hopping
	Bounding
	Depth jumps
	Medicine ball throwing

When selecting these exercises we should seek to:

	Replicate any movement patterns required for sporting objectives.
	Encourage a variety of planes of movement to promote balanced physical development.

More traditional free weight based exercises can be utilised to enhanced muscular power. Ideally these exercises should be performed explosively and require the individual to impart momentum to the bar. This momentum should then be accommodated by the inclusion of a 'catch' or receiving phase at the end of each lift. Some examples of such lifts would be:

	Power cleans
	Push press
	Power snatch (one or two handed)

Plyometric Training:
Plyometric training or jump training has been used by many individuals to increase their explosive power. Plyometric training enhances power by encouraging the body to make efficient use of the stretch-shortening cycle (SSC) and the energy stored within the elastic components of muscle and connective tissue. Plyometric training consists of stimulating muscles through a sudden eccentric stretch prior to any voluntary concentric effort.

The rapid eccentric load stimulates muscle spindles to initiate to protective stretch-shorten cycle reflex. This reflex maximises force production during the voluntary concentric phase providing the point of transition is brief (note that the point of transition is the time taken between decelerating the eccentric phase and initiating the concentric phase). Siff (2003) contends that if the transition phase is any greater than 0.15 seconds the exercise ceases to become Plyometric. Using jumping as an example, in order to minimise the transition phase the individual shall be encouraged to spend minimal time in contact with the floor. Imagining the floor to be red hot and unbearable to touch is a useful teaching point for this type of Plyometric activity.

Due to the nature of Plyometric exercises it is suggested that the load used should remain relatively low. Siff (2003) suggests the use of bodyweight or light medicine balls over heavy weights for Plyometrics, because increased loads would slow the movements down negating the potential benefits of exercise.

Sequencing the Workouts
Exercise order:
When constructing a workout that includes power exercises, as your personal trainer I'll be able to provide you with various options. Beachle et al (2000) suggests that he following sequence should be adhered to:

	Power exercise (Plyometric) in order of skill/complexity
	Non-power compound exercises (squats, deadlifts, bench press)
	Core exercises

Additional to these guidelines the basic programme design rules will always be applied. These are:

	Promote muscular balance
	Train large muscles first
	Perform complex and high skill exercises first
	Train synergists and fixators last