This simple principle is what separates the greatness from mediocrity. Training for sports requires more than buying the program of a jacked up someone looking for a pump.
Why do we choose certain exercises more than others? To give you the most bang for your bucks. You can’t obviously replicate a given movement and add it in the gym (ex: please don’t shadow box with 10 pounds) but you can improve « specific » movement strength curves and functional strength with specific exercise selection and planification.
Let’s take a closer look at MMA fighters.
As soon as the foot is planted on the floor, a chain of movement is initiated to give maximum power and speed. The kicking leg is extending, in preparation for the hip flexors and knee extensors to load or eccentrically stretch for the forward movement in order for the kicking leg to strike. Then, the planting leg and foot (left) points out, opening up the hip, planting the foot and firing up the posterior chain for a fraction of a second, while both arms arm pull down and back as a contro-lateral force to increase the power of the hip flexors to lift the kicking leg.
The final stage is the impact, extending the knee a few degrees, at its most powerful angle, just at the right moment, the last 15 degrees. In this case, think working with bands and chains, telemark squats/split squats, etc.
Additionally, the kick is preceded by a long jab, which has a specific purpose/combination. The jab extends the left arm, which increases the range between the left shoulder and the right kicking hip and leg. See anything in particular? What type of exercise could come close to it?
A coach should see some posterior chain, hip flexors and core work. As for upper body, pulling strength will have a huge impact on kicking strength, which is what coaches often disregard. Pull ups, front barbell split squats and lunges are some of the best tools you can add to your programs to name just a few.
This is the why of predictor lifts. They are not the only thing to focus on, in fact, they are just a small piece of the equation. However, an increase of strength, power or explosiveness in some of the predictor lifts will bring on an almost immediate increase in sport performances.