Plyometrics and Athlete Development – Part I

This Newsletter will be divided into 3 Parts (April/May/June) to discuss the importance of Plyometrics in developmental programs and the underlying concepts for correct application and implementation. Parts II and III provide a series of upper- and lower-body exercises that can be incorporated into programs.‍ ‍

*The Post by Jim Kielbaso has been partially modified by Schloder.‍ ‍

Recently, I have observed numerous developmental programs across several sports in which plyometric concepts and principles were misapplied. USA IYCA CEO Jim Kielbaso (Impact Sports Performance) sent me his thoughts in an email post titled “Plyometrics Through the Ages: Are You Training Power- or Just Practicing Jumps?”

… Kids jumping on boxes that are way too high, doing endless “explosive” circuits, chasing highlight clips instead of real development. It looks impressive. But a lot of it isn’t helping athletes—and in some cases, it’s increasing their risk of injury. Plyometrics, when used correctly, are among the most powerful tools we have to build speed, power, and resilience. When used incorrectly, they’re just noise…(Kielbaso, 2026).

As coaches head into practice sessions this week, it is a great opportunity to reflect and question whether athletes are actually developing power, or just practicing jumping.
‍ ‍
The Two Types of Plyometrics (and why it matters)

IYCA CEO Jim Kielbaso discussed in his post two key categories to be emphasized:

Power-Based Plyometrics (Intensive)
These are the maximum-effort outputs:

• Long jumps

• Vertical jumps

• Med Ball Throws with variation: standing, sitting, single or with a partner The goal is to produce as much force as possible.

  • Low Reps. Full recovery. High Intent.

Reactive / Extensive Plyometrics (Reactive Strength Index-RSI)
These are about Speed and Elasticity:

• Line hops

• Pogos

• Quick bounds/bounding

  • The goal: How fast can an athlete absorb and reapply Force?

  • Most athletes are undertrained here, which shows up in their speed and change of direction.

The Big Mistakes: ‍ ‍

• Chasing height instead of ability.

• Athletes jump onto a high box, and it looks great… But a closer look reveals:

  • Knees tucked to chest

  • Deep landing

  • Slow ground contact versus quick rebounding

  • Valgus effect* That’s not Power - that’s a Workaround.

• The question of usage is not the height of the box but how much force is actually produced.

*Valgus Effect: It is a medical term describing a condition where a bone or joint segment, distal to the midline, is angled outward (laterally), away from the body’s center, most commonly affecting the knees (knock-knees) or feet. Causes include genetics, arthritis, injury, or developmental issues.

Focus Per Age Group:

Ages 8–10

• FUN – Fitness and Fundamentals. Keep it playful with many variations!

  • Skipping, hopping, bouncing, bounding

  • Jump rope/single and group

  • Teaching basic landing mechanics and shock absorption

  • Focus on Rhythm, Coordination, and confidence.

*If it looks like a High school workout, you’re doing too much!

Ages 11–13

*TEDC Stage:
Teaching – Error Detection/Cocorrection Phase

• Emphasize landing mechanics

• Introduce basic Jumps and Medicine Ball exercises/drills

• Begin low-level Reactive work

Most important question:

• Can they control their body? If not, they’re not ready for more intensity!

Ages 14+

We train with Purpose.

• Balance power and reactive work

• Focus on intent and quality

• Align plyos with speed and strength training

Remember:

• Too much power work = slow athletes

• Too much reactive work = weak athletes

• You need both.

Watch for:

Paying Attention to:

• Ground contact: Quick and elastic, or slow and heavy?

• Landing: Controlled or collapsing?

• Intent: Are they actually trying to be explosive?

Most Importantly:

• More Reps won’t fix bad movement...they reinforce it!

• If mechanics break down, stop the set. Avoid pushing through it.

Overall:

• Plyometrics aren’t just about jumping.

• They’re about:

  • Producing force

  • Absorbing force

  • Transitioning between the two...quickly

  • That applies to every movement, sprint, and change of direction athletes make.

  • When applying the correct principles and performing exercises and drills correctly, everything improves.

Plyometric training isn’t snazzy, stylish, chic, dashing, glamorous, sparkling, or striking, but it is moving efficiently with good rhythm and flow.

• Stay healthy

• Perform when it matters

• When stepping onto the floor, field, mat, court, or staring block, the focus is on quality, intent, and progression.

References:

Kielbaso, J. (2026, April 19). Plyometrics through the ages: Are you training power or just practicing jumps? IYCA (International Youth Coaching Association). Post. jim@impact-sportsperformance.com‍ ‍
Schloder, M.E. (2026, to be released). E P-P T (Effective Pre-Post Training). Chapter: Training with Plyometrics, pp. 179-193.
Schloder, M.E. (2016). Ballet for swimmers: Modified exercises for cross-training. Dual DVDs. Interactive PDF. Calgary, Alberta, Canada: www.coachingbest.com Schloder, M.E. (2016). Ballet for athletes: Modified exercises for cross-training. Dual DVDs. Interactive PDF. Calgary, Alberta, Canada: www.coachingbest.com Schloder, M.E. (2018). The Kalos exercise collection: PDF [45 pages]. Calgary, Alberta, Canada: www.coachingbest.com