How Plyometrics Works

This section serves as a comprehensive guide to help coaches and athletes comprehend the intricacies of optimizing power development through plyometric exercises. The pursuit of optimal power training has witnessed the evolution and integration of various training methods. Historically, heavy resistance training, typically involving weights of 80 to 95 percent of one-repetition maximum (1RM), has been employed to enhance strength and, consequently, athletic performance. Contemporary strategies, however, blend diverse training modalities, including plyometrics and dynamic weightlifting, aiming to elevate explosive power. 

The relationship between strength and power in training is often nuanced. Generally, as resistance increases, the speed of movement decreases. When athletes exert maximal effort, the movement’s speed tends to be slow. Conversely, reducing overall resistance augments the speed of force development and, consequently, increases power. Given that power production is a pivotal determinant of success in sports, athletes are advised to employ training techniques that facilitate the transition of strength gained from heavy, albeit slow, resistance training to high-velocity movements. Plyometric training, characterized by rapid force absorption (e.g., landing from a jump) and force generation (push-off of a jump), plays a crucial role in enabling this conversion. Research indicates that both heavy lifting with external resistance and plyometrics, when utilized individually, effectively enhance power output. The logical next step was to explore whether combining these systems could yield even greater improvements, particularly in specific skills like vertical jumping. Indeed, the integration of both methods has shown promising results, demonstrating significant enhancements in athletic abilities.

Resistance Training for Power: The Dynamic Shift

For resistance training to focus on increasing power, lifts must adopt a more dynamic nature. The jump squat exemplifies this approach, involving a load of approximately 30 to 60 percent of 1RM. This exercise engages all basic components of muscle contraction, preparing athletes for higher-intensity plyometric exercises.

The 5-5-5 squat can be executed with body weight or up to 60 percent of 1RM, utilizing a medicine ball or barbell. The athlete assumes a start position with specific attention to foot placement, abdominal engagement, and spinal alignment. This drill incorporates controlled squats, a quick squat with a different tempo, and explosive vertical jumps. The careful integration of tempo and movement dynamics ensures the desired training effect while minimizing injury risks. Extensive research supports the notion that maximal strength levels can be enhanced by using lighter weights in conjunction with highly accelerated movements. In Eastern European literature, this training method is described as one form of complex training. The integration of maximal power training and plyometrics can yield rapid increases in power, albeit with the acknowledgment that its intensity may be too stressful for prolonged training cycles exceeding 12 weeks. Nevertheless, it finds application in shorter training periods, often in the later stages of the preparation (off-season) cycle within a periodization training scheme.

This type of training proves instrumental in refining the body’s ability to develop force rapidly, ultimately enhancing impulse forces crucial in activities such as jumping, running, and throwing. The overarching message emphasizes the importance of a holistic training approach, acknowledging that athletic development encompasses multiple modes of exercise, each contributing to the athlete’s overall prowess.

Research on Depth Jumps: Unlocking Plyometric Potential

The depth jump, a pinnacle in plyometric training, has captivated researchers seeking to unravel its impact on athletes. Originating as shock training for Russian athletes, this maximal-effort plyometric approach aimed to cultivate explosive speed and strength. Early Soviet research, notably led by Dr. Yuri Verkhoshansky, laid the groundwork for understanding the effectiveness of depth jumps in enhancing athletes’ speed and strength capabilities. Verkhoshansky’s programs, rooted in resistance training and jump-focused drills, contributed to the Soviet Union’s track and field success, garnering global attention and adoption of these techniques, later coined as plyometrics in the United States.

Verkhoshansky, a proponent of evidence-based coaching, emphasized the importance of depth jump height for achieving specific training goals. He designated 0.8 meters for maximum speed and 1.1 meters for maximal dynamic strength, limiting the jumps to 40 in a single session, performed no more than twice a week. Over time, plyometric training has evolved, becoming more adaptable and recognized for its safety and injury-reduction benefits across various athlete populations. A subsequent study by Verkhoshansky and Tatyan underscored the efficacy of depth jumps compared to weight training, jump-and-reach, or horizontal hops in developing speed and strength. The specificity of plyometric exercises, particularly depth jumps, in fostering vertical velocity became apparent. Nevertheless, determining the optimal height for depth jumps has spurred numerous studies, with conflicting findings rooted in varied experimental designs.

Practical considerations in determining the proper height hinge on an athlete’s ability to maximize the body’s center of gravity elevation post-depth jump. Excessive height can lead to prolonged ground contact, undermining the utilization of the stretch reflex phenomenon, essential for powerful jumps. Recent research highlighted the connection between drop jump height and quadriceps activation, emphasizing the need to balance elevation with efficient amortization.

A systematic approach to determine maximum depth jump height involves measuring an athlete’s standing jump-and-reach, followed by performing depth jumps from incrementally increasing box heights. The process continues until the athlete can no longer reach the standing jump-and-reach height, with the last successful box height establishing the starting point for the drill.

Distinguishing between depth jumps (DJ) and countermovement jumps (CMJ), recent studies have explored their mechanical disparities. While the CMJ relies on flexing the hips, knees, and ankles for a rapid descent before a vertical jump, the DJ incorporates eccentric loading via a vertical drop. Athletes trained with plyometric exercises, including DJ, demonstrated more significant improvements in peak power and vertical jump height compared to other groups. Motor learning emerges as a crucial factor in depth jump effectiveness, requiring athletes to grasp timing and positioning nuances. Verbal cues and feedback significantly influence jumping characteristics, as seen in studies emphasizing different jump aspects. The focus on absolute height or ground contact time altered the technique and outcomes of depth jumps, reinforcing the importance of specific training for sport-related tasks.

While the depth jump remains extensively studied and integral to assessing injury risk, the holistic perspective recognizes the contribution of both horizontal and vertical jump training to overall athletic improvement. As running and jumping involve a combination of horizontal and vertical components, incorporating both dimensions in training ensures a comprehensive approach for athletes aiming to enhance performance in various activities. The depth jump, once a simple yet profound movement, continues to be a subject of exploration, unveiling its multidimensional impact on athletic prowess.

Mechanics of Vertical Jumping: Unveiling the Art of Flight

Vertical jumping, a seemingly instinctive athletic move, is, in reality, a skill that can be honed and taught to athletes. Delving into the mechanics of this dynamic action, a closer examination reveals a well-orchestrated sequence. The jump commences with a countermovement, where the center of gravity swiftly drops, involving flexion in the hips, knees, and ankles. Simultaneously, the trunk tilts forward, and the arms are drawn behind the body’s midline.

Preceding the upward thrust, a rapid extension of the hips, knees, and ankles occurs, propelled by the force generated from both the arms and legs. The arms play a pivotal role in this process, swiftly moving forward, exerting a downward force on the body during the initial jump phase. As the arms swing past the midline, the force applied to the ground is recovered, analogous to releasing the compression on a spring, propelling the body upward. Understanding the mechanics of the arms’ contribution emphasizes the importance of their position. To maximize force development, athletes should extend their arms as far back and as straight as possible. The balance lies in finding the optimal arm bend; longer levers generate more force, while shorter levers facilitate swifter movement. This principle is evident in the contrasting arm swing styles of elite triple jumpers and high jumpers.

Research conducted by Dr. Everett Harman and his team sheds light on the significance of the countermovement and arms in vertical jumping. The countermovement, acting as a stretch reflex, is shown to contribute up to 6 percent of total jump height, while the arms can enhance overall jump height by as much as 21 percent. The downward force exerted by the arms in the early jump phase aids in maintaining the body position for effective muscle engagement.

Despite the importance of the countermovement, the research suggests that specific sport situations may not demand a substantial countermovement for effectiveness. For scenarios where speed and reaction time take precedence, a smaller countermovement can be equally effective, as seen in a volleyball block. Given the substantial contribution of the arms to jump height, integrating resistance training exercises that strengthen these areas is imperative. Exercises like reverse pull-downs, triceps dips, and shoulder swings become essential components of comprehensive jump training programs.

Using Muscle Physiology to Optimize Plyometric Training: 

Plyometric training, rooted in the stretch-shortening cycle, offers a powerful avenue to enhance power output and sport-related performance. The interplay between eccentric (lengthening) and concentric (shortening) muscle actions defines many sport skills. For instance, in a long jump, the body undergoes slight flexion upon landing, followed by rapid extension during takeoff.

In the basketball slam dunk scenario, the supporting leg undergoes rapid eccentric action as it absorbs the body’s weight, followed by a concentric action to initiate the jump. These muscle responses, operating without conscious thought, highlight the role of the stretch-shortening cycle in executing dynamic movements. The amortization phase, a critical aspect distinguishing average from elite athletes, involves the timing of muscle actions. Successful execution of this phase, influenced by training and motor learning from plyometric drills, maximizes an individual’s genetic potential in speed and power. Plyometric activities conclude with a momentum phase, propelling body segments as a result of accumulated forces during unloading.

The duration of the contact, from loading to unloading phases, significantly impacts performance. A shorter contact duration generates higher forces and joint moments, emphasizing the importance of a quick coupling between eccentric and concentric actions. This quick coupling, occurring within hundredths of a second, is pivotal for effective plyometric training.

The concept of plyometrics, designed to address the development of a shorter amortization phase, underscores the importance of learning. While strength and inherent speed are crucial, an athlete’s ability to shorten the amortization phase is greatly influenced by skill training atop a foundation of strength development. This intricate interplay of muscle physiology and training optimization forms the backbone of plyometric excellence.

Considerations for Program Design in Plyometric Training:

Program design in plyometric training demands careful consideration, balancing safety, skill progression, and individual characteristics. Several key considerations influence the design of effective plyometric training programs across all levels.

Movement Skills: Teaching athletes the fundamental concepts of plyometric activities is crucial. Coaches should emphasize the distinction between eccentric and concentric strength, underscoring the role of the stretch-shortening cycle in quick starts. Initial activities should be of lower intensity, focusing on skill development and preparation. Proper landing technique is essential, with the athlete’s feet nearly flat, minimizing ground contact time. The arms play a pivotal role, with the elbows swung behind the body to develop force into the ground. Age-appropriate techniques and progressions are vital, ensuring athletes build a strong foundation in plyometric movements.

Age: Attention span and cognitive abilities differ across age groups, influencing how plyometric training is introduced. While elementary school children respond well to plyometric-like activities presented in imaginative contexts, young athletes approaching pubescence can benefit more from direct training. As athletes mature and reach high school, individualization becomes possible, allowing for more structured and sport-specific plyometric drills.

Training Level: Considering the intensity level and the athlete’s experience is crucial when structuring a plyometric training program. Progression from elementary to advanced exercises should align with the athlete’s proficiency and physical readiness. Beginners may start with low-intensity drills, gradually advancing to more complex exercises. High school athletes with weight training experience can handle moderately intense plyometrics, while advanced, college-level athletes may engage in high-intensity ballistic-reactive exercises.

Time Frame or Cycle: Introducing plyometric training necessitates strategic timing within an athlete’s overall training program. Physical development, typically achieved over a 4- to 6-week period, aligns with the concept of periodization. Plyometric training should follow a strength phase, gradually integrated before the competitive season. Coaches must assess the athlete’s sport demands and schedule plyometric training accordingly. The timing is critical, ensuring athletes benefit from increased explosiveness and reactivity without risking fatigue during peak competition periods.

General Adaptation Syndrome and Recovery: Understanding the General Adaptation Syndrome, as described by Hans Selye, emphasizes the importance of exposing the body to various stimuli for optimal adaptation. Off-court or off-field training serves not only for physical improvement but also for recovery. Diverse exercise selection in plyometric training exposes athletes to different stressors, promoting adaptation through neurological and muscular adjustments. Careful attention to program design details, such as exercise selection, intensity, repetitions, and frequency, ensures a well-rounded plyometric program that enhances athletic performance.

In essence, a thoughtful approach to plyometric program design considers the athlete’s age, training level, movement skills, and the broader training cycle, aligning with principles of safety, progression, and adaptability. These considerations, seemingly minor, collectively shape the selection, intensity, and frequency of exercises, ultimately determining the program’s efficacy in optimizing athletic performance.

Plyometric Training Equipment: 

Plyometric training, known for its adaptability, can be executed both indoors and outdoors. However, certain prerequisites must be met, with ample unobstructed space being a fundamental requirement. Whether on gym floors, in expansive weight rooms, or on outdoor fields, the landing surface must be carefully chosen. It should provide a yielding surface to minimize lower extremity impact, options ranging from Resilite wrestling mats to spring-loaded gymnastics floors and grass or synthetic playing fields.

What stands out in plyometric training is its minimal dependence on prefabricated equipment. The essential items needed are both basic and easily obtainable. These include plastic cones for jumping barriers, specially constructed boxes with varying heights, hurdles adjustable for difficulty levels, foam barriers, and steps such as stairways or bleachers. Weighted objects like medicine balls complement upper-body exercises and enhance lower-extremity training.

Best Warm-Up Drills: 

A crucial principle in all exercise programs is the incorporation of lower-level activities as a precursor to major training efforts. Warm-up activities, specific or related to larger efforts, are instrumental in preventing injuries and establishing motor patterns relevant to speed development and jumping ability. While not classified as true plyometrics due to their lower voluntary effort, warm-up drills serve to develop fundamental movement skills and elevate the body’s core temperature.

The warm-up or submaximal plyometric activities encompass various drills performed over short distances with ample recovery between exercises. Typically conducted over 10 to 20 meters, these drills include marching drills that break down running into component parts, jogging drills that can be modified to be plyometric, and skipping drills emphasizing reciprocal limb movements. Each warm-up session consists of 8 to 12 exercises performed 2 to 4 times, aiding in skill enhancement and preparation for more complex skills.

Marching Drills: 

Marching drills, designed to mimic running movements, deconstruct running into its essential components. This breakdown allows coaches to emphasize posture, joint angles, range of motion, and foot placement. Jogging drills, with variations emphasizing speed development, can be modified to be plyometric. Ankling, a specific jogging drill, utilizes the elastic component of calf musculature to enhance foot movement speed during sprinting.

Skipping Drills:

Skipping drills, focusing on reciprocal limb movements, are essential for motor development. These drills involve exaggerated forms of reciprocal motion, ideal for submaximal plyometric activities that warm up athletes. Straight-line skipping emphasizes quick takeoff and landing, with arms moving reciprocally. Single-leg skipping serves as both a drill and an assessment tool, allowing for the evaluation of each leg’s speed, strength, and endurance. Skipping with a pop-off exaggerates the motion for heightened ankle plantar flexion and lift off the ground.

Footwork Drills: 

Footwork drills, as advocated by John Frappier in his Acceleration Training program, serve as valuable supplements to plyometric conditioning programs. These drills, designed to improve agility and quick changes of direction, can also double as effective warm-up exercises. Examples include shuttle drills, multidirectional side-shuffle drills, and drop-step drills, all emphasizing ankle complex engagement. These drills build on simple footwork movements, preparing athletes for more complex plyometric exercises.

Lunging Drills: 

Derived from the fundamental lunge exercise, lunging drills offer diverse forms, such as forward, side, crossover, disassociated multidirectional, reverse, and walking lunges. Employed as submaximal drills, they provide an excellent means of preparation before undertaking extensive amplitude jumps. These drills, often performed with body weight, prove instrumental in building foundational strength in the upper hip and thigh regions.

Alternative Movement Drills: 

Beyond the previously classified movements, alternative drills aim for distinct effects in specific body areas. Each activity focuses on achieving a specialized outcome:

Backward Running: 

Backward running stands out as a valuable exercise for hamstring and hip extension strength. Particularly effective in preparing the hamstrings for the eccentric forces encountered in straight-ahead running, backward running also finds application in rehabilitation after knee and hamstring injuries. Executed best outdoors, with a slight incline if possible, the technique involves short, compact backward steps, maintaining a low center of gravity. Athletes may adopt a defensive back posture or an alternative posture resembling backward skipping, emphasizing distance coverage.

Carioca: 

Carioca, a familiar movement in football coaching, focuses on improving hip rotation and foot placement. The athlete moves laterally down a line, lifting one knee and foot in a crossover position, then rapidly switching to a reversed position. The upper body remains relatively stationary during this sideways movement. Some coaches advocate emphasizing knee lift to accentuate acceleration of the lead knee, although not essential.

These alternative movement drills expand the repertoire of conditioning exercises, targeting specific areas of the body and promoting comprehensive strength and agility development. Incorporating these drills into training programs contributes to a well-rounded approach to athletic conditioning and injury prevention.

Disassociation Drills: 

Disassociation drills constitute functional exercises demanding both body balance and trunk stability concurrently. These exercises compel the upper body to move in one direction while the legs execute a different action. While numerous versions exist, a simple progression proves particularly effective.

Training Considerations: 

Plyometric training can be tailored for individuals or groups, each approach offering unique benefits. Individual training emphasizes personal responsibility, concentration, and follow-through, fostering individual development. Group training extends beyond physical skills, encompassing social aspects like communication, cooperation, trust, and goal-setting feedback.

Implementing a plyometric training program requires careful planning, considering the athlete’s sport, specific movements, age, experience, and athletic maturity. The initiation of such a program carries significant responsibility, emphasizing an enjoyable, organized, and progressive training environment.

Intensity: 

Intensity in plyometrics is the effort exerted in performing a task. Unlike weightlifting, where intensity is regulated by weight, plyometric intensity is influenced by exercise type. Ranging from simple tasks to complex, stressful exercises, intensity can be modified by incorporating light weights, adjusting platform height, or extending jump distances. While classifying exercises by intensity has limitations, the provided guidelines aid coaches in program design.

Volume: 

Volume in plyometrics refers to the total work in a session or cycle, often measured by foot contacts. Low-intensity warm-ups, not included in foot contact counts, should progressively prepare athletes. The number of jumps depends on variables like athlete level, goals, and integration with resistance training. Bounding activities, emphasizing exaggerated running, are measured by distance. Starting with 30 meters per repetition, the distance can be increased to 100 meters as athletes progress.

Frequency: 

Frequency entails the number of repetitions and exercise sessions in a training cycle. Practical experience suggests 48 to 72 hours of rest for full recovery between plyometric sessions. The principle applies, with variations, to lower-extremity training. Plyometrics, being stressful, demand prioritization in workout sequencing. Integration with weight training or running programs can vary, with weight training remaining a priority for developing and maintaining strength.

In conclusion, plyometric exercises, due to their demanding nature, should precede other programs. Integration with weight training in later cycles, known as complex training, is feasible. Tailoring frequency and considering recovery is crucial to ensuring maximal, high-quality efforts in plyometric exercises, optimizing athletic development and minimizing injury risks.

Recovery: 

Recovery plays a pivotal role in determining the efficacy of plyometrics in developing power or muscular endurance. For power training, longer recovery periods of 45 to 60 seconds between sets or groupings are essential to maximize recovery between efforts. A work-to-rest ratio of 1:5 to 1:10 ensures proper execution and intensity, aligning with the anaerobic nature of plyometric training. Shorter recovery periods of 10 to 15 seconds may shift the workout towards aerobic demands due to metabolic system stress.

For combined strength and endurance, circuit training, involving continuous movement between exercises, is effective. The preparation (off-season) cycle should incorporate general motor exercises, gradually transitioning to sport-specific exercises as the preseason approaches. In sports like long jumping or pole vaulting, plyometrics can extend into the in-season cycle, but for vertical-dominant sports like basketball, adjusting plyometric volume during the season may be prudent based on the team’s schedule.

Time Per Session and Cycle Length: 

In a beginner’s plyometric program, actual exercise time should range from 20 to 30 minutes, with an additional 10 to 15 minutes for warm-up and cooldown activities, emphasizing stretching and low-intensity movements. Advanced athletes may extend workout durations for longer, more complex drills.

The length of a training cycle depends on the days available before the season starts. For beginners, a 4 to 6-week basic plyometric program emphasizes skill development. A more extended 12 to 18-week cycle aligns with off-season and preseason training.

Safety: 

Safety in plyometrics hinges on the principle that more is not necessarily better. If a workout feels too easy, impulsively adding more exercises is ill-advised. Quality, not quantity, is the primary goal. Considerations for large, heavy athletes and young athletes emphasize gradual progression and strength development.

Coaches must ensure plyometric programs do not increase injury risks. Fatigue, often at the end of practice, can compromise control, leading to injuries like sprained ankles or twisted knees. Prudence is crucial in planning and integrating plyometrics into overall training.

Adding weight to plyometrics, known as the overload principle, demands caution. Beginners should avoid weighted vests, belts, or bands. Even elite athletes with extensive training experience only occasionally use added weight, and this should be approached with care.

Proper Execution of Plyometrics:

While numerous program design elements exist, coaches should prioritize perfecting jumping and landing mechanics, especially in the early training cycle. Proper landing mechanics are critical for injury prevention and effective takeoff. Evaluation methods, such as box jumps and stepping off platforms, aid in assessing and practicing landing techniques.

Landing softly, distributing weight evenly, and flexing all three joints of the lower extremity are key points in landing technique. Observing athletes from different angles helps identify weaknesses and areas for improvement. Quadriceps-dominant landings and ligament dominance are concerns that need targeted training.

Arm Action: 

Proper arm action during jumping activities contributes significantly to maximal efforts. Athletes should use their arms strategically, such as cocking them back before a jump to generate momentum. Contrast drills can exaggerate arm activity, emphasizing their crucial role in lifting the body off the ground. Coaches can guide athletes on utilizing their arms effectively for various jumps, enhancing overall performance.