Have you seen Instagram lately? They’re everywhere. Squat jumps. Lunge jumps. Jumps with a twist. Use plyos to really get that heart rate going. Do 5 rounds of 30 squat jumps, 20 push-ups, 10 burpees. Do 100 box jumps for time.
Whatever. And by whatever, I mean what the fuck.
Plyos are meant to be fast, reactive, and explosive. As such, they are naturally going to be limited by our ability to create energy to supply those highly explosive actions. In reality, they are far more connected to our nervous system and honing that for power production than for muscle development. There’s also more efficient, safer ways to work on anaerobic intervals.
Think hard. Have you ever tried to max out a 30 second time period of squat jumps truly jumping as high as you can for each jump? I would venture to guess it would be REALLY challenging. There is going to be drop off in energy production because biology says so.
Here’s the biology tie-in. Plyo and power work are tailor-made to be kept to shorter intervals in conjunction with the ATP-CP energy system. This system provides the most amount of energy we can create, making it incredibly valuable for explosive movements like power cleans, box jumps, squat jumps, etc. However, we only get that massive output potential for about 10-15 seconds. After that we downshift into fast glycolysis. There is value up to about 30 seconds, but that’s about it.
I would also challenge anyone who has ever played any sport or worked out to find an athletic competition that requires the participant to jump consecutively, with as much power as possible for 30 seconds. Football, one jump. Basketball, maybe 2 or 3. Baseball, 1. Hockey, that would just be scary. Crossfit, still not a sport. At most you might need three jumps, in reality, one jump will cover you for just about every sport.
There’s no crossover. There’s no developmental or growth improvements for that type of endurance power production. Why even do it? Keep it simple and the next time someone tells you to do lunge jumps for 60 seconds, roll your eyes annoyingly, do a handful of reps at a time, keep it clean and crisp, and be smart!
Side bar: Beware of doing these at the end of a session or class after you’ve already burned through a significant amount of work. The risk of injury goes up due to fatigue. Plyos should be done early in the workout to potentiate the nervous system, not beat the crap out of it at the end.