By Ken Jakalski
In 1975, the first school where I taught ordered a Leaper machine. An isokinetic trainer, the device was the brainchild of legendary swim coach James “Doc” Councilman and Mini-Gym president Glen Henson. They saw it as a breakthrough in the sports equipment industry. It allowed athletes to do any number of reps at max effort because the machine adjusted with every rep as athletes became fatigued.
Many people heralded the Leaper for its ability to help athletes make big gains in their vertical jump. Indiana basketball star Kent Benson claimed that, after a summer’s work on the Leaper, his vertical jump improved by 4 to 6 inches. He led Indiana to the 1976 NCAA basketball title, which helped the marketing. So did several newspaper articles and even a Sports Illustrated feature on athletes benefiting from the new technology. The company sold over ten thousand Leapers in the 1970s and 1980s. NASA even launched a Leaper into space to help Skylab astronauts maintain their strength in zero gravity.
An Expensive Clothing Rack
My experience with the Leaper (which, in homage to jackrabbits, I nicknamed the Lepus) was different. My athletes hated it. After using it for a month, they draped their warmup jackets and pants on it. Despite the hype, why didn’t they like the Leaper?
For one thing, there was nothing “tangible” indicating strength gains. Athletes would watch a manual dial. The faster they applied force, the higher up the dial moved. This seemed to be an immediate turn-off. As I think about this now, the best explanation may be in one of the many great lines Carl Valle has presented on issues related to analysis and feedback: “Imagine if we painted over the numbers on weight plates and only eyeballed vertical jumps. Most coaches would cry heresy or think one is crazy.”
Perhaps my athletes chose to use the Leaper as a clothing rack for the same reasons. The only way they could gauge their progress was by way of that force dial, which was cheap and clunky-looking even by 1970s standards. Henson himself was not satisfied with mechanical assessment monitor on those early units. Current models now have LCDs that count reps, measure power output and work in foot-pounds, and provide an average work number for all reps done—all good things. And other current products, such the 1080 Quantum Robotic System discussed in a previous blog, that provide meaningful data while continually challenging athletes to achieve higher levels of force, power, and speed.
My Leaper experience became the first of many “epiphany moments” during my track and field career. It pointed out to me the importance of creating the kind of progressively demanding training activities that provide valuable feedback, so athletes maintain their focus and their interest remains high.
Introducting Split Jumps
One example of this is “Split Jumps.” Originally, this in-place alternating-leg jump movement involved a couple of cones and short sections of fiberglass rods. Athletes began at a lower height—like 2 to 3 inches—and progressed to higher heights—4 to 6 inches. I drilled holes in the cones so advancing to a higher height was easy.
How do I complex that drill once athletes get bored with the initial movement?
First, I add a lateral jump component. They jump sideways, clearing one set of cones, and then go back to their original position.
Video 1. Split Jump with lateral component.
Next, I have athletes go two at a time while attempting 180s without breaking stride. The key here is to have athletes make their rotations both to the right and left. Some athletes have a natural rotational bias to turn one way. Making them go the opposite way is challenging.
Video 2. Splits Jumps with 180 complex.
I further complex the tandem jumps by bouncing, lobbing, or chest-passing a med ball to athletes. The goal is catching and firing the ball back without breaking the movement. These throwbacks involve eccentric contractions. They should be fast and explosive. Athletes should not bring the ball to their chests before releasing. This is not easy, especially when the ball is bounced or lobbed. I also fake the toss, looking at one athlete but throwing to the other. This action further forces concentration. If an athlete stops because he has broken his rhythm or disengages the rod, he could still get hit with the ball if he is not looking ahead. Athletes watching this exercise enjoy seeing a teammate get plunked.
Video 3. Splits Jumps with med ball pass.
Duration and Safety Concerns
How long do I keep them split jumping? Early in the season, until one of them breaks stride or drops mishandles a med ball. Two new athletes take their place. As they get better, I stop when they begin slowing down, which is clear from their longer ground contact times.
For safety reasons, I stopped using fiberglass rods and went with 2×4 foam blocks that are 36 inches long. Our pit reconditioner supplies these for free. The next clip shows the foam block in the horizontal position.
Video 4. Foam blocks enhance athlete safety.
I can complex the drill, either by having athletes go from the 2-inch height (horizontal) to 4-inch (vertical) or, as in this last clip, by having athletes attempt the “top-of-the-line,” a clean 360 without any break in movement. This is the most difficult way I can complex the activity. Runners like to get to this point because they know it’s hard to do. Teammates enjoy watching someone attempting a 360. They are pretty vocal when he sticks a clean one going both to the right and left without ever breaking stride. Incidentally, the athletes in these last two clips are distance runners.
Video 5. Add a 360 to the split jump without a break in movement.
What do I most like about these split jumps? For one, they can be done in limited space. We have no indoor facility. To avoid having to come back later in the evening to use the gym after basketball practices, we work out in a classroom or the high school hallways. The first three clips take place in one corner of my assistant coach’s tech lab!
Most important is that split jumps are just fun to do. They engage the athletes in various levels of complexity. Concentration and arousal are always high.
Forty years after the dawn of the Leaper, my athletes now have a few more protocols on which they can confidently hang their hats.
Please share so others may benefit.