Notes

Outline

Chapter 19 Plyometric Training

Plyometric Training Those activities that reach maximum force in the shortest possible time Rate of tension development Plio = more, increase Metric = measure, length Pliometric = eccentric contraction (literally) Pliometric = stretch-shortening cycle (usage)

Plyometric Mechanics and Physiology Power – combination of force and speed Plyometrics enhances power

Mechanical Model and Plyometric Exercise Elastic energy in the musculotendinous components is increased by rapid stretch and then stored. Then immediately followed by concentric muscle action SEC = series elastic component PEC = parallel elastic component

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Neurophyisological Model of Plyometric Exercise Potentiation  (change in F-V characteristics of the muscle’s contractile components caused by stretch) of the concentric muscle by the use of the stretch reflex. If a concentric muscle action does not immediately follow a stretch (e.g., too long a time between stretch and concentric action or movement over too large a range), a potentiating ability of the stretch reflex is negated

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Three Vertical Jumps Squat Jump Counter movement Jump Approach Run and Jump

Plyometric Program Design Mode Intensity Frequency Duration Recovery Progression Warm-up Period

Mode Determined by the body region performing the exercise Lower body plyometrics can be used by virtually any athlete and any sport (T&F throwing and sprinting, soccer, VB, Basketball, FB, and baseball) Require maximal amount of force in a short amount of time.

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Upper-body Plyometrics Rapid powerful, upper-body movements in sports like baseball, softball, tennis, golf, and the throws in T&F Plyometric drills for the upper body are not used as often Medicine ball throws, catches, and several types of push-ups

Trunk Plyometrics Stretch reflex is not sufficiently involved during many trunk exercises to potentiate muscle activity Exercises  for the trunk can be performed “plyometrically” with modifications to the movement, making the movements shorter and quicker.

Intensity Amount of stress placed on the muscles, CT, and joints Plyometric drills cover a wide range of intensities; skipping is relatively low intensity, while drop jumps place high stress on muscles and joints. As intensity increases volume should decrease.

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Frequency Number of plyometric training sessions per week ranging from one to three Depends on the sport and time of year. Recovery time controls the frequency; usually 48-72 hours

Recovery Complete and adequate recovery is required for plyometric drills involving maximum efforts; for drop jumps 5-10s between reps, 2-3 minutes between sets The drills are not cardiorespiratory conditioning but power training. Do not train the same body area two days in succession.

Volume Number of repetitions and sets performed during a single training session. Lower-body:  # of foot contacts per workout, but distance can be used with bounding

Table 19.4 Appropriate Plyometric Volume Experience         Beginning Volume Beginner               80-100* Intermediate         100-120 Advanced              120-140 *contacts per session

Program length Research  has not determined the optimal plyometric program length, but usually last 6-10 weeks Vertical jump does improve quickly within 4 weeks after the beginning of the program Should be used during the off-season, preseason and in-season mesocycles, and go from low intensity to higher intensity  as in the resistance training

Progression A form of resistance training and must follow the principles of progressive overload Progressive overload is the systematic increase in training frequency, volume, and intensity in various combinations. As intensity increases, volume decreases

Warm-up General warm-up Stretching A specific Warm-up For plyometrics, low-intensity dynamic movements

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Plyometrics and Other Forms of Exercise Combination of plyometrics and resistance training  (see table 19.6) Heavy resistance training is normally not done with plyometrics on the same day Complex training: a combination of high-intensity resistance training followed by plyometrics Traditional resistance exercises may be combined with plyometric exercises to enhance gains in muscular power. i.e., squat jump at 30% of 1RM along with the regular squat program

Table 19.6  Sample Schedule for Integrating Resistance Training and Plyometrics Day          Resistance Training        Plyometric Training Monday     High-intensity UB           Low-Intensity LB Tuesday     Low-intensity LB            High-Intensity UB Thursday    Low-intensity UB           High-Intensity LB Friday         High-Intensity LB           Low-intensity UB UB = upper body; LB = lower body

Safety Considerations Not inherently dangerous There is some risk of injury. Not a sufficient strength and conditioning base, inadequate warm-up, improper progression of lead-up drills, inappropriate volume, or intensity for the phase of training, poor shoes or surface, or simply a lack of skill.

Pretraining evaluation Athlete must understand proper plyometric technique and possess a sufficient base of strength, speed, and balance. Sufficient maturity both physically and psychologically.

Strength For lower body plyometrics, the athlete’s 1RM squat should be 1.5 times body weight For upper-body plyometrics, the bench-press 1RM should be at least 1.0 times the body weight of larger athletes (those over 100kg), or 1.5 times body weight for the smaller athletes (<100kg); or 5 clap push-ups in a row.

Speed For lower body plyometrics the athlete should be able to perform 5 reps of the squat with 60% of body weight in 5s or less Concurrent participation in a sprint training and speed-specific resistance training programs are helpful For upper-body plyometrics the athlete should be able to do 5 reps in the bench press with 60 % of body weight in 5s or less

Balance Dynamic balance Static balance Moving away from static balance Moving into static balance

Age High intensity plyometrics like drop jumps are contraindicated for those children whose growth plates have not fused. Psychological maturity is necessary Must follow directions

Physical Characteristics Athletes >100 kg may be an increased risk of injury, by increasing the compressive forces on the joints; drop jumps greater than 18 inches are not recommended Previous injury or abnormalities of the spine, upper or lower extremities may increase the risk of injury

Equipment and facilities Landing surface – shock-absorbing; excessively thick exercise mats will increase the time of amortization phase and not allow efficient use of the stretch reflex Minitramps and thick mats may be used to introduce someone to plyometrics, or for use by those who are recovering from injuries, they are not effective in plyometric training. Training area – Equipment – boxes, medicine balls Proper footwear –

"Supervision –" Supervision – Depth Jumping – recommended heights for depth jumping range from 16-42”, with 30-32” being the norm. Over 100kg the recommended height ranges from 20-30”.