So what’s the difference?
Box jumps are when you jump up onto a box and STEP back down.
Box jumpovers are when you jump up onto the box and JUMP back down (usually on the other side).
The physiological effects are DRAMATICALLY different.
There are 3 major effects which I will talk about and which are the reasons why I chose jumpovers rather than simple box jumps.
NUMBER 1: Muscle strength adaptation
If you’ve ever worked with a personal trainer at the gym, you might have heard him/her say that you should focus on slowing down the eccentric part of the movement.
If, for example, you’re doing a push-up, then you focus on slowing down the part when you’re going towards the floor.
The reason is that the eccentric part of the movement causes a lot more tears in the muscle fibres, which in turns causes the muscle to grow stronger when you recover.
The concentric part (pushing up during the push-up) causes a lot less damage to the muscle and therefore the rate of muscle growth and strength growth is much lower.
Now if you’re a runner (or triathlete or obstacle racer), each time your foot lands when you run, your leg muscles are resisting that eccentric force.
This causes small tears in the muscle fibres, and eventually your muscles get tired and you slow down.
But if you’ve trained your muscles by forcing them to deal with this kind of stress (by jumping down from the box), your muscles will last a lot longer before getting fatigued.
NUMBER 2: Tendons and Ligaments
How many runners or athletes get a “‘muscle injury”?
It’s quite rare right? Most injuries are “connective tissue” injuries: tendons and ligaments.
If you just jump up onto the box, you’re not really training your tendons and ligaments to deal with the stress of absorbing the “shock” of your foot landing when you run.
Remember that when you’re running, each time your foot lands, your ENTIRE body weight is on that leg, and those small tendons and ligaments in that leg.
Jumping DOWN from the box trains those tendons and ligaments to become better shock absorbers (which is what they are designed to do).
NUMBER 3: Bone Density
Studies have shown that RUNNERS tend to have GOOD bone density, while CYCLISTS tend to have LOW bone density and higher risk of fractures.
WEIGHTLIFTERS tend to have GOOD bone density while ROWERS tend to have LOW bone density.
Astronauts who go into space tend to lose a lot of bone density during their stay.
Ever wonder why?
It’s because of the effect of your body weight & gravity on your bones.
When your bones are subjected to the stress of carrying your bodyweight against gravity, they are stimulated to increase density to cope with the added stress.
This makes the bones STRONGER over time.
If you subject those bones to an even higher level of stress (running, lifting heavy weights), the stimulus is even higher and bone density increases even further.
This is why older people who keep up the habit of lifting weights in the gym tend to suffer far fewer fractures compared to the general population of their age group.
But do you know which athletes have the best bone density of all?
People who practice gymnastics subject their bones to massive impacts from all the times when they’re flying through the air and have to “land hard” on their feet.
That high level of repetitive stress causes the body to substantially increase bone density (as well as ability of muscles, tendons & ligaments to absorb shocks).
But you don’t have to be a gymnast to get similar results: by jumping off a box onto the ground, you are also subjecting your bones to similar stressors, and therefore you will achieve some of the same benefits.
Disclaimer: if you’re not used to this high level of exercise stress, start gradually with something like rope skipping, and then graduate up to a low box, and then move onto higher and higher boxes.