During my years as a college gym rat, I never greatly appreciated plyometrics or truly understood the value plyometric exercise could bring to my training. Whenever I would join my “wide-receiver” training partner for a plyo workout I would always think, “yeah, these exercises are great for athletes who want to jump higher, and increase their agility and explosiveness, but probably not that useful for the general population.” I took a therapeutic exercise course in PT school to help me better understand the other benefits of plyometrics and the value it can bring to other populations.
Instead of immaturely thinking that plyometric exercises are only good for jumps, I’ve come to understand that this type of training is the pure combination of strength and speed of movement (1). In chapter 13 of their book, Musculoskeletal Interventions, Michael Voight and Steven Tippett discuss plyometric exercise as the bridge that connects strength speed, power, and skill (1). They define plyometrics as a “quick, powerful movement involving prestretching the muscle and activating the stretch-shortening cycle to produce a subsequently stronger concentric contraction.”(1) They state the main purpose of this type of training is to “heighten the excitability of the nervous system for improved reactive ability of the neuromuscular system.”(1) They also state that the goal of plyometric training should be to decrease the time needed between the eccentric muscle contraction and the “initiation of the overcoming concentric contraction.”(1) This timeframe between contractions is called the amortization phase.(1) During this phase there is the electromechanical delay, in which the muscle switches from “overcoming work to acceleration in the opposite direction.(1) The longer the duration of the amortization phase, the less force you are able to produce via the stretch-shortening cycle and the previously stored elastic energy will be lost as heat.(1) Hence, the goal of plyometric training will be to improve your ability to quickly and forcefully react to stimuli.(1)
This brings us to the physiological magic of the stretch -shortening cycle, which is the combination of the eccentric-concentric contraction.(1) The stretch-shortening cycle or in other words, a concentric contraction preceded by an eccentric one, is present during many daily life activities. Eccentric activity, or the duration of an activity that produces tension while a muscle is lengthening, occurs during deceleration, landing, descending stairs, assuming a seated position from standing, throwing, and changing directions.(2) Whether during athletics or daily life, the stretch-shortening cycle occurs allowing our muscles to store elastic energy via the stretch and release it during the shortening contraction.(1)
A fun fact that has become ingrained in my head after hearing it repeatedly in exercise science courses in college is: during the initial weeks of beginning a resistance training program, the increases in muscular strength are not due to any increase in muscle size, but instead are due to neural adaptations.(3) These neural adaptations arise due to the “development of more efficient neural pathways along the route to the muscle.”(3) I’ve always heard that 6 weeks is around the time when the neural adaptations learned from the initiation of a training program plateau.(4) That notion has always been vaguely depressing for me to digest.
However, if your first 6 weeks initiating a resistance training program involve the biggest rise and inevitable plateau of your neural muscular adaptations, perhaps incorporating some plyometric drills into your routine could reopen those neural flood gates and create some plateau-busting spikes in your neuromuscular efficiency. Voight and Tippett state that “training with an explosive prestretch of the muscle can improve the neural efficiency,” which will result in increased neuromuscular performance.(1) Plyometric training has the potential to create change within your neuromuscular wiring that can result in an increased force output via increased control of contracting muscles and their synergists.(1) This translates into more fluid and automatic movements that can produce a “greater net force even in the absence of morphological adaptation of the muscle.”(1) Which means hypertrophy #GAINZ are not a prerequisite to generating more force. We get stronger initially through other means.
To summarize, plyometrics can be described as quick eccentric loading of your musculoskeletal complex, which will train your neuromuscular system to increase your preparedness to handle increased strength loading.(1) Plyometrics can also increase your preparedness to respond with max speed to the lengthening of muscles.(1) So maybe your neural efficiency doesn’t have to completely hit that depressing plateau around week 6 of a new resistance training program after all. Plyometric exercise isn’t just for athletes. It can create a more fluid neural network to better connect strength, speed, power, and skill.(2) Improved reactive abilities can be of value to people of many different training backgrounds.
It is recommended to get cleared for participation in a plyometric program by your physical therapist or doctor. A physical therapist may perform a biomechanical exam and functional tests to determine if you would have an increased risk of injury while performing plyometric exercise.2
Plyometric Exercise Examples
- Jump Rope
- Cone Jumps (side to side, in-line, forward & backward)
- Plyo-Ball Shoulder Throws
- Depth Jumps (double or single leg)
- Wall Push Ups
- Tuck Jumps
- Ladder Drills
- Plyo-ball Sit Up & Throw
- Two-Hand Chest Pass
- Depth Jump with Catch/Throw
Quick Plyometric Tips
- Total plyometric workout volume is measured in number of foot contacts (low intensity 75-100) (mod 200-250)(1)
- Frequency 2x/week (no more than 3/week)(1)
- Greatest benefit after normal workout(1)
- Begin with double leg activities before progressing to single leg
- Suggested recovery time between sets(1):
- Power training: work/rest 1:3 or 1:4
- Endurance training: work/rest 1:1 or 1:2
P.S. If you’re interested in more specific jumping progressions I’ve written extensively in the past about these. Click the links below for my favorite plyometric progressions:
- Voight ML, Hoogenboom BJ, Prentice WE. Musculoskeletal Interventions: Techniques for Therapeutic Exercise. United States of America. The McGraw-Hill Companies, Inc.; 2007.
- Demers K. Eccentrics/Explosions, and Plyometrics. Therapeutic Exercise II Course Notes. University of St. Augustine for Health Sciences. Austin, TX. Published Summer 2016. Accessed August 21, 2016.
- Resistance Training: Adaptations and Health Implications. University of New Mexico: Len Kravitz, Ph.D. https://www.unm.edu/~lkravitz/Article%20folder/resistben.html. Accessed September 15, 2016.
- Sale DG. Neural adaptation to resistance training. Medicine and Science in Sports and Exercise. 1988; 20(5 Suppl): S135-45.