The following is an exclusive excerpt from the book Developing Power, published by Human Kinetics. All text and images provided by Human Kinetics.

Assessing Power in Youth Populations

A wide of range of equipment now exists to assess the kinetics and kinematics of isometric and dynamic athletic performance, with the most predominant testing protocols involving various forms of jumping, sprinting, or projection (51) (see chapter 2). Measurement tools previously used to assess neuromuscular power in youth populations include force plates and linear position transducers (15, 27), mobile contact mats (43), motion analysis systems (37), and isokinetic dynamometry (11). Another piece of equipment often used to determine short-term power output in youth is the cycle ergometer, on which children and adolescents have often been assessed for performance using the Wingate anaerobic test (2). Regardless of the testing equipment or protocol used, the manner in which these tests are administered is critical. Youth require familiarization sessions, clear and child-friendly instructions, and, wherever possible, child-sized equipment.

While studies have used the Wingate anaerobic cycle test to assess short-term power output, performance is less dependent on neuromuscular coordination and arguably more reliant on biochemical endurance (50). Consequently, in order to determine how two children compare in terms of neuromuscular power or in order to assess the effectiveness of a training intervention, practitioners are encouraged to use test protocols that require single maximal efforts at submaximal velocities and loads. The test protocol that appears most often in the pediatric literature and that is used most frequently by practitioners is the vertical jump (45). As stated in chapter 2, using a force plate, peak power is quantified from the ground reaction forces and velocity of center of mass displacement, whereas peak power can be calculated indirectly by jump height and body mass using a contact mat. Because of their relative ease of administration, vertical-jump protocols are routinely used within the pediatric setting, with practitioners favoring lower-cost contact mats or similar jump-and-reach equipment over more costly equipment such as force plates. Vertical-jump performance has been used to track motor skill development in school age youth (25, 31), assess physical performance in young athletes (48), and monitor the effectiveness of training interventions (47) and is commonly used as a component of talent identification protocols in sport (69).

Research shows that muscular power increases in a nonlinear fashion throughout childhood and adolescence, with both boys and girls of all ages and maturity levels able to show improvement as a result of growth and maturation alone (7). This is an important factor for researchers and practitioners to consider as they plan and deliver strength and conditioning programs, because growth and maturity-related increases in neuromuscular power may be misinterpreted as training-induced adaptations. Consequently, practitioners should understand the typical gains in performance expected as a result of growth and maturation in addition to the measurement error associated with the testing equipment used in order to confidently determine meaningful changes in performance associated with training.

With Developing Power, the National Strength and Conditioning Association (NSCA) has created the definitive resource for developing athletic power. With exercises, drills, assessments, analysis, and programming, this book will elevate power and performance in all sports. The book is available in bookstores everywhere, as well as online at the NSCA Store.