Jan Müller
Low hanging fruit and Rate of force development (RFD) - Week 1
Low hanging fruit
Training history is important when it comes to exercise selection and deciding what to focus on. Quick gains can be made by what we like to call low hanging fruit. When it comes to myself I have noted down a few facts down below:
I train a lot of attractors in the gym because of my work etc.
I didn't really lift heavy weights for probably 2 months.
Aside from some examples/recordings, I didn't really sprint for about 2 months.
Lately, my training has been mainly aimed at getting to know some martial arts.
No or a bare minimum of explosive and reactive jumps.
So going by these points I know for a fact that:
Recruitment and rate coding are far from optimal.
Energy-transport and proximo-distal functioning should be okay.
Muscle-tendon-unit (MTU) stiffness is far from optimal.
Reduction of muscle slack with co-contractions should be relatively okay.
This gives me some pretty straightforward stuff to work on which will probably help me in achieving my goals.
Rate of force development
RFD is a huge athletic performance indicator. Ground contact times in most actions are really short so there is a very limited amount of time to generate force. Improving RFD will impact performance in accelerations and jumps (Thus, low hanging fruit based on training status). Some well and lesser known factors that influence RFD are for example:
Muscle fibre type
Rate coding (The rate at which motor units discharge, higher in balistic movements)
Recruitment (The number of recruited motor units, Higher in slow movement)
Motor unit synchronisation
Muscle slack (Parts of the MTU must be aligned and be taut before force is transmitted.)

So there are a number of factors that go into increasing RFD and it's up to you as a coach to integrate the above principles into your exercises.
For me personally, I like performing exercises where the reduction of muscle slack plays an important role. You can reduce muscle slack by performing a countermovement or by creating pre-tension. Since countermovements take time to perform, and time is a valuable resource in sports, we want to eliminate countermovements in order to reduce muscle slack with pre-tension. (source: Frans Bosch Strength training and coordination)
So if we look at the exercise in the video to the left, the speed is pretty high (good for encoding) but the resistance is pretty low (not ideal for recruitment). There is no countermovement so the muscle slack must be reduced by pre-tension. Since it's also a jump, it's quite similar to the motor pattern of the countermovement jump which should work towards improving the motor unit synchronisation (specificity).
The exercise below is drastically different which makes it focus on different mechanisms behind rate of force development. Try for yourself to reason which ones are mainly at play here!
This may be a little different from the more strength-coordination exercises you are used to seeing from me. But exercises are just a means to an end and the selection should always be based on the goal you are trying to achieve. When it comes to improving countermovement jump height I believe these are very effective exercises. When it comes down to on field performance in chaotic, open skills for professional athletes, these type of exercises should only be a (small) part of their training regime.
Let me know if you have any questions!