Plyometric Training ("plyos")
Plyometrics (“plyos”) are typically a series of jumping and bounding movements of which the aim is to increase the strength of the joints, tendons and ligaments in the legs, as well as to increase muscular power, as differentiated from strength. The difference between strength and power is the speed of the movement, with powerful movements being performed more quickly. A plyometric exercise is a quick, powerful movement using the spring-like action of the tendons. Jumping rope and sprinting can be considered plyometric exercises, with jumping rope being a great option for an extended warmup prior to a strength training (ST) workout.
Power has been associated with improvements in running economy (RE). Studies have appeared in the scientific literature demonstrating that eliminating portions of endurance training in favor of explosive activities or adding plyos to an existing running program for six to nine weeks can improve RE and performances in short-distance racing without needing to see an accompanying change in VO2max. These benefits are evident regardless of ability, gender or age.
These results are best understood in that any time a muscle group becomes stronger and more powerful, fewer muscle fibers are recruited to perform the given task, thus allowing the muscle group to have more fibers in reserve for continued work. Basically, this means that less energy is used to cover the same distance. Since the discovery of this concept, it has been shown that power training, not just ST, will lead to enhancements in running economy. Of course there is no substitute for running if one wants to run faster and farther; however, during peak racing season, as the run volume gradually decreases, plyos are another option for maintaining high-intensity workouts (in addition to speed workouts).
A plyos program is typically done one or two times a week and is based on the total number of foot contacts, or “touches.” For beginners, the recommended range is between 60 - 100 touches for a few weeks, before progressing toward 100 touches for a few more weeks and then beyond (capping the total touches at 140). Reps can be performed as double-leg exercises (both feet jump, or contact the ground, at the same time) or as single-leg exercises, although single-leg plyos should be reserved for experienced athletes. Sometimes additional equipment can be used to add variety and difficulty into these workouts, like small hurdles and boxes.
Plyos are a great compliment to ST and can even be done as a warm-up on lower body ST days, but don’t underestimate how strenuous these exercises can be. For many of the exercises, it’s not necessarily the muscles that are the target for strengthening; rather, it’s the joints, tendons and ligaments. With that said, these aren’t always muscle-burning exercises or workouts, so don’t mistakenly take that mentality into a plyos workout. With that said, before starting any plyos training, I recommend completing at least six weeks of general ST in order to strengthen these body parts that incur more stress when performing various jumping and hopping exercises. I recommend plyos as long as an athlete is familiar/comfortable with jumping exercises in general. Do not do plyos unless there is 100% certainly on the landing mechanics for each exercise. Similar to how I frame a discussion on proper ST technique, if you couldn’t teach jumping and landing mechanics to a small group, then your plyos form probably isn’t ideal.