Logic is a function of the brain that improves with data. You can gain data in two ways. The first is by reading detailed information without omissions. The second is through experience.
Unfortunately, it is hard to recover from some experiences. I prefer to gather detailed data before experimenting.
Ankle weights and wrist weights is an example of how logic may completely backfire if you don’t think it through.
The idea of using ankle and wrist weights in martial arts is to improve the kicking and punching speed.
It seems to make sense that if you can strap a 10 pound weight to your ankle, practice kicking with it, you would be able to kick faster when you take them off.
There are three missing pieces in that theory.
First, when you add weights to your ankle, you create a separation within your ankle joint. The ankle weight is resting on top of your foot pulls the foot away from your shin bone. Your ankle is designed for compression force as you stand, walk, run or jog on it.
Your ankle is not designed to be pulled. In fact, many of effective grappling techniques are based on locking and creating separation in the ankle to force submission. Second, by adding an ankle weight, you create additional force on your knee joint that increases the gap. This is not as bad as the ankle but at high-speed kicking, this separation impacts how you’re the muscles around your knee contract.
You could easily lose control over the balance of the muscles that move your knee safely. For example, the contraction of your quadriceps that must be balances with controlled relaxation of your hamstrings is no longer in balance. You create additional force to move the ankle weight without a compensating balance to control the relaxation of hamstrings.
Third, ankle weights shift your center of your gravity away from your naval and hips. Your stabilizer muscles are designed around a stable center of gravity. Once you move that center of gravity, your stabilizer core muscles can no longer work effectively.
Does this mean that you should never use wrist and ankle weights?
No. These three considerations should help you learn and even design your motions to improve your speeds without harming yourself.
For example, instead of practicing a front kick with ankle weights that could easily damage your knee, you can practice straight leg raises which engages your hip flexors and your core. Your front kick becomes faster when your take the weights off.
If you experience pain in your lower back with the straight leg raises, you know your abs and glutes are not strong enough and you need to move to a core exercise with ankle weights like a weighted knee tuck to build up your core.
All this requires that you think through the process, pay attention to your body and don’t jump to conclusions because it seems to make sense.